NASA/CP-2001-211029

National E,Jucators' Workshop:Update 2000

Standard Experiments in

and Technology

Engineering, Materials Science,

Compiled by

Edwin J. Prior and James E. Gardner

Langley Research Center, Hampton, Virginia

James A. Jacobs

Norfolk State University, Norfolk, Virginia

Louis A. Luedtke

National Composite Center, Kettering, Ohio

August 2001
The NASA STI Program Office... in Profile

Since its founding, NASA has been dedicated

to the advancement of aeronautics and space

science. The NASA Scientific and Technical

Information (STI) Program Office plays a key

part in helping NASA maintain this

important role.

The NASA STI Program Office is operated by

Langley Research Center, the lead center for

NASA's scientific and technical information.

The NASA STI Program Office provides

access to the NASA STI Database, the

largest collection of aeronautical and space

science STI in the world. The Program Office

is also NASA's institutional mechanism for

disseminating the results of its research and

development activities. These results are

published by NASA in the NASA STI Report

Series, which includes the following report

types:

TECHNICAL PUBLICATION. Reports of

completed research or a major significant

phase of research that present the results

of NASA programs and include extensive

data or theoretical analysis. Includes

compilations of significant scientific and

technical data and information deemed

to be of continuing reference value. NASA

counterpart of peer-reviewed formal

professional papers, but having less

stringent limitations on manuscript

length and extent of graphic

presentations.

TECHNICAL MEMORANDUM.

Scientific and technical findings that are

preliminary or of specialized interest,

e.g., quick release reports, working

papers, and bibliographies that contain

minimal annotation. Does not contain

extensive analysis.

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technical findings by NASA-sponsored

contractors and grantees.

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Collected papers from scientific and

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often concerned with subjects having

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Specialized services that complement the

STI Program Office's diverse offerings include

creating custom thesauri, building customized

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research results.., even providing videos.

For more information about the NASA STI

Program Office, see the following:

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Page at http;//www.sti.nasa.gov

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NASA/CP-2001-211029

National Educators' Workshop:Update 2000

Standard Experiments in Engineering, Materials Science,

and Technology

Compiled by

Edwin J. Prior and James E. Gardner

Langley Research Center, Hampton, Virginia

James A. Jacobs

Norfolk State University, Norfolk, Virginia

Louis A. Luedtke

National Composite Center, Kettering, Ohio

National Aeronautics and

Space Administration

Langley Research Center

Hampton, Virginia 23681-2199

Proceedings of a workshop sponsored jointly by the National

Aeronautics and Space Administration, Washington, DC;

Norfolk State University, Norfolk, VA; the National Composite

Center, Kettering, Ohio; the National Institute of Standards and

Technology, Gaithersburg, MD; the Department of Energy, Oak

Ridge National Laboratory, Oak Ridge, TN; Wright-Patterson

Air Force Base, OH; University of Dayton, Dayton, OH; and

Gateway Coalition, Drexel University, Philadelphia, PA

and held in

Dayton and Kettering, Ohio

October 29-November 1, 2000

August 2001
The use of trademarks or names of manufacturers in this report is for accurate reporting and does not constitute an [

official endorsement, either expressed or implied, of such products or manufacturers by the National Aeronautics and

Space Administration.

Available from:

NASA Center for AeroSpace Information (CASI)

7121 Standard Drive

Hanover, MD 21076-1320

(301) 621-0390

National Technical Information Service (NTIS)

5285 Port Royal Road

Springfield, VA 22161-2171

(703) 605-6000
PREFACE

NEW:Update 2000, hosted by the National Composite Center, Wright-Patterson Air

Force Base, and Wright State University, in Ohio, was held October 29 - November 1,

2000.

The 15th Annual NEW:Update was built on themes, activities and presentations based on

extensive evaluations from participants of previous workshops as we continued efforts to

strengthening materials education. About 150 participants witnessed demonstrations of

experiments, discussed issues of materials science and engineering (MS&E) with people

from education, industry, govemment, and technical societies, heard about new MS&E

developments, and chose from nine, three-hour mini workshops in state-of-the-art

laboratories. Faculty in attendance represented high schools, community colleges,

smaller colleges, and major universities. Undergraduate and graduate students also

attended and presented.

This year's hosts provided excellent support. The National Composite Center, WrightPatterson Air Force Base, the University of Dayton's Research Institute, Wright State

University, and Advanced Integrated Manufacturing helped to coordinate the many

scientists, engineers, professors and other staff, provided funding, opened their facilities,

and developed presentations and activities.

NEW:Update 2000 participants saw the demonstration of about fifty experiments and

aided in evaluating them. We also heard technical updates relating to materials science,

engineering and technology presented at mini plenary sessions

The experiments in this publication provide valuable guides to faculty who are interested

in useful activities for their students. The material was the result of years of research

aimed at better methods of teaching materials science, engineering and technology. The

experiments developed by faculty, scientists, and engineers throughout the United States

and abroad add to the collection from past workshops. There is a blend of experiments

on new materials and traditional materials in addition to engineering concepts.

Experiments underwent an extensive peer review process. After submission of abstracts,

selected authors were notified of their acceptance and given the format for submission of

experiments. Experiments were reviewed by a panel of specialists through the

cooperation of the International Council for Materials Education (ICME). Comments

from workshop participants provided additional feedback, which authors used to make

final revisions, which were then submitted to the NASA editorial group for this

publication.

The ICME encourages authors of experiments to make submissions for use in the Journal

of Materials Education (JME). The JME offers valuable teaching and curriculum aids,

including instructional modules on emerging materials technology, experiments, book

reviews, and editorials to materials educators.

As with previous NEW:Updates, critiques were made of the workshop to provide

continuing improvement of this activity. The evaluations and recommendations made by

participants provide valuable feedback for the planning of subsequent NEW:Updates.

°..

Iii
NEW:Update 2000 and the series of workshops that go back to 1986 are, to our

knowledge, the only national workshops or gatherings for materials educators that have a

focus on the full range of issues on strategies for better teaching about the full

complement of materials. NEW:Updates, with its diversity of faculty, industry, and

government MSE participants, served as a forum for both formal and informal issues

facing MSE education that ranged from the challenges of keeping faculty and students

abreast of new technology to ideas to ensure that materials scientists, engineers, and

technicians maintain the proper respect for the environment in the pursuit of their

objectives.

We demonstrated the second edition of Experiments in Materials Science, Engineering &

Technology, (EMSET2) CD-ROM with over 450 experiments from NEW:Updates. This

CD-ROM is another example of cooperative efforts to support materials education. The

primary contributions came from the many authors of the demonstrations and

experiments for NEW:Updates. Funding for the CD came from both private industry and

federal agencies. Please see the attached information for obtaining the CD. To obtain a

demonstration edition or to order the full version of EMSET2 CD-ROM call 1-800-922-

0579 or go to Intemet site http://MST-Online.nsu.edu and link to the World of Materials,

Science, & Technology.

We express our appreciation to all those who helped to keep this series of workshops

viable. Special thanks go to those on our national organizing committee, management

team, hosts, sponsors, and especially those of you who developed and shared your ideas

for experiments, demonstrations, and novel approaches to teaching.

We hope that the experiments presented in this publication will assist you in teaching

about materials science, engineering and technology. We would like to have your

comments on their value and means of improving them. Please send comments to Jim

Jacobs, School of Science and Technology, Norfolk State University, Norfolk, Virginia

23504.

The use of trademarks or manufacturers' names in this publication does not constitute

endorsement, either expressed or implied, by the National Aeronautics and Space

Administration.

iv
MANAGEMENT TEAM

James A. Jacobs

Workshop Co-chairperson

Norfolk State University

Louis A. Luedtke

Workshop Co-chairperson

National Composites Center

Diana P. LaClaire

Assistant Director

Norfolk State University

Robert Berrettini

International Council on Materials

Education

Paul Brown

International Council on Materials

Education

Raymond G. Boeman

Oak Ridge National Laboratory

S. Raj Chaudhury

Norfolk State University

Harry J. Couch

National Composite Center

Jeanne Deatherage

ASM International Foundation

Leonard W. Fine

Columbia University

James E. Gardner

NASA Langley Research Center

Said Jahanmir

National Institute of Standards and

Technology

Kenneth L. Jewett

Materials Science & Engineering

Laboratory-NIST

Thomas F. Kilduff

Thomas Nelson Community College

Steve Krause

Arizona State University

P. K. Mallick

University of Michigan-Dearborn

James V. Masi

Northeast Center for

Telecommunication Technologies

Alfred E. McKenney

IBM Corporation, Retired

Robert L. Mott

University of Dayton

Tony Polsinelli

Advanced Integrated Manufacturing

Center

Edwin Prior

National Aeronautics and Space

Administration

Heidi Ries

Air Force Institute of Technology

Laura L. Sullivan

American Society for Engineering

Education

Katie E. G. Thorp

AFRL/MLBC Wright-Patterson Air

Force Base

C. David Warren

Oak Ridge National Laboratory

V
Acknowledgements

We greatly appreciate the support provided by these organizations:

Department of Energy Office of Energy Efficiency and Renewable Energy

National Composite Center

National Aeronautics & Space Administration Langley Research Center

School of Science and Technology Norfolk State University

Materials Science & Engineering Laboratories-NIST

Energy Efficiency and Renewable Energy Program Oak Ridge National Lab

Air Force Research Laboratory Materials and Manufacturing Directorate Wright-Patterson AFB

United States Automotive Materials Partnership

Center for Lightweight Materials & Processing University of Michigan-Dearborn

The ASM International Foundation

University of Dayton

Gateway Engineering Coalition

Advanced Integrated Manufacturing Center

American Society for Engineering Education

Columbia University

Dayton Power & Light

Edison Welding Center

Fifth Third Bancorp

Gottschlick & Portune

Hardcore Composites Operations LLC

International Council for Materials Education

McDonald Investments (Key Bank)

Mead World Headquarters

Northeast Center for Telecommunication Technologies

Reynolds & Reynolds

Wright State University

vi
CONTENTS

PREFACE .............................................................. iii

MANAGEMENT TEAM .................................................... v

ACKNOWLEDGEMENTS .................................................. vi

REVIEWERS OF EXPERIMENTS ............................................ xi

EMSET2 CD ROM ........................................................ xii

GROUP PICTURE ....................................................... xiii

PARTICIPANTS .......................................................... xv

SESSIONS ........................................................... xxix

MINI WORKSHOPS ............................................ xxxvii

EDUCATIONAL OUTREACH AT WRIGHT-PATTERSON AIR FORCE BASE ............ 1

Kathy Schweinfurth - Wright-Patterson Air Force B ase

PROGRAMMABLE POWDER PREFORM PROCESS .............................. 19

Correen Schneider - National Composite Center

EXPERIMENTS IN LIQUID CRYSTALS: DIFFERENT STATES AND DEVICES .......... 41

James V. Masi - Northeast Center for Telecommunications Technologies

DOOR RADIUS VS OPENING FORCE OR FREE-BODIES VS FISH-SCALES ............. 55

Edward L. Widener - Purdue University

STRUCTURE AND MECHANICAL PROPERTIES OF THERMOPLASTIC

COMPOSITES ........................................................... 59

W. Richard Chung - San Jose State University

LIGHTWEIGHT AUTOMOTIVE MATERIALS DATABASE ......................... 69

P. K. Mallick - University of Michigan-Dearborn

FRACTURE BEHAVIOR OF NYLON MONOFILAMENT FISHING LINE ............... 81

Wayne L. Elban - Loyola College

EARTHQUAKES, MATERIALS AND AN EDIBLE VILLAGE: AN EDUCATIONAL

EXPERIMENT FOR HIGH SCHOOL STUDENTS ................................ 113

Neda Fabris - California State University, Los Angeles

DATA REPORTING AND ANALYSIS IN SCIENCE AND ENGINEERING COURSES ...... 121

John P. Ellwood, Shingara S. Sandhu - Clafin University

vii
A REMOTE EXPERIMENT FOR CLASSROOM USE 133

Richard B. Griffin, Carlos L. Yapura, Dimitris C. Lagoudas - Texas A&M University

LECTURE WORK NOTES FOR INTRODUCTORY MATERIALS

ENGINEERING CLASSES ................................................. 141

Stephen Krause - Arizona State University

A DECADE OF CERAMICS OUTREACH ...................................... 149

Mark Glasper - The American Ceramic Society

MODERN MODEL AIRPLANES AS FLYING COMPOSITES ........................ 153

L. Roy Bunnell - Southridge High School

MICROWAVE DIELECTRIC ANALYSIS OF SELECTED MATERIALS ................ 159

J. No Dahiya - Southeast Missouri State University, J. A. Roberts -

University of North Texas

LEARNING THE PRINCIPLES OF GLASS SCIENCE AND TECHNOLOGY

FROM CANDY MAKING .................................................. 169

Himanshu Jain, Isha H. Jain - Lehigh University

DETERMINATION OF VISCOSITY USING A FALLING SPHERE VISCOMETER ........ 183

Harvey Abramowitz - Purdue University Calumet

TWISTY GLUE STICKS OR TORSIONAL CHARACTERISTICS OF HOT

MELT ALL PURPOSE GLUE STICKS ........................................ 197

Alan K. Karplus - Western New England College

MAKING THE JUMP FROM ROTE LEARNING TO APPLICATION IN 50 MINUTES ..... 215

Donna C. S. Summers - University of Dayton

DEVELOPMENT OF COMPOSITE MATERIALS MANUFACTURING AND

EXPERIMENTAL EVALUATION FACILITIES FOR UNDERGRADUATE

ENGINEERING STUDENTS ................................................ 221

Ronald B. Bucinell - Union College

NANOTECHNOLOGY EDUCATION: EXPLORING A COMPACT DISK STAMPER ....... 227

B. L. Ramakrishna, Eddie W. Ong, Jeremy Rowe, Andrew Chizmeshya - Arizona State

University

PROJECT 100: ACCELERATED COMMERCIALIZATION OF FRP COMPOSITE

BRIDGE DECK PANELS .................................................. 243

Mark Mutton - National Composite Center

BASIC CERAMICS: FIRING TEMPERATURE AND SIZE EFFECTS .................. 273

Kurt C. Schulz - University of the Pacific

USING HISTORICAL EXAMPLES TO ENHANCE TEACHING OF "MODERN"

ENGINEERING AND SCIENTIFIC SUBJECTS .................................. 285

Daniel Eylon - University of Dayton

o°°

Vlll
ANTI-STOKES TRANSITIONS IN POLYFLUORENE . .'........................... 293

Bruno Ullrich - Bowling Green State University

A REVOLUTION IN MANUFACTURING COMPOSITES: CURING WITH

ELECTRON BEAMS ..................................................... 297

Don Klosterman - University of Dayton

STUDY OF THE MAGNETOSTRICTIVE EFFECT ............................... 333

John Marshall - University of Southern Maine

COMPOSITE MATERIALS IN CHEMICAL ENGINEERING ........................ 339

Tony E. Saliba - University of Dayton

OFF-SITE SCANNING MICROSCOPY OF SILVER-COPPER ALLOYS:

FIRST STEPS TO INTERNET-BASED MICROSCOPY ............................. 359

L. Roy Bunnell - Southridge High School, Stephen K. Kennedy - RJ Lee Group, Inc.

UNIVERSITY - INDUSTRY COOPERATION AND INSTRUCTION IN MATERIALS

SCIENCE AND ENGINEERING: GOOD INTENTIONS AND REALITY ................ 369

Witold Brostow, Victor M. Castano, Pablo E. Montemartini - University of North Texas

MASS TRANSFER SENSORS AND MEMS DEVICES TO MEASURE SHEAR ............ 375

Vijay Modi - Columbia University

THE MAGSET PROJECT MATERIALS AS THE GATEWAY (AND GLUE) FOR

SCIENCE, ENGINEERING AND TECHNOLOGY ................................ 383

Don L. Evans - Arizona State University

TECHNOSPHERE: AN ENVIRONMENTAL STUDIES SEMESTER FOR

UNDERGRADUATE MATH, SCIENCE, ENGINEERING, AND TECHNOLOGY

MAJORS .............................................................. 395

Leonard W. Fine, Morton Friedman - Columbia University

OVERVIEW OF MATERIALS SCIENCE AND ENGINEERING LABORATORY.

PREVIEW NEW:UPDATE 2001 .............................................. 403

Gale A. Holmes - National Institute of Standards and Technology

USING MST-ONLINE TO IMPROVE INSTRUCTION ............................. 429

James A. Jacobs, Curtiss E. Wall - Norfolk State University

THE BLACK BOX ....................................................... 437

Mike L. Meier - University of California, Davis

PARAMETER SELECTION IN AUTOMATIC GAS METAL ARC WELDING ............ 443

Alessandro Rengan, Mahmoud Abdallah, John Mingus - Central State University

LAB MANUAL & RESOURCES FOR MATERIALS SCIENCE, ENGINEERING

AND TECHNOLOGY ON CD-ROM ........................... ... ............. 451

James A. Jacobs, Alfred E. McKenney - Norfolk State University

ix
THE BI-SN EQUILIBRIUM PHASE DIAGRAM .................................. 463

Mike Meier - University of California, Davis

RELATING ATOMIC BONDING FORCE AND ENERGY CURVES WITH

OBSERVED MATERIAL PROPERTIES ....................................... 483

Robert A. McCoy - Youngstown State University

THE BRAGG BUBBLE RAFT FILM .......................................... 491

Mike Meier - University of California, Davis

GALVANOSTATIC POLARIZATION CURVES FOR TEACHING PURPOSES PART III .... 497

Carlos E. Umana - University of Costa Rica

STRESS CONCENTRATION EFFECTS IN A THIN SHEET ......................... 505

Aaron S. B licblau - Swinbume University of Technology

CURRENT AND FUTURE USE OF STRUCTURAL AUTOMOTIVE COMPOSITE

MATERIALS ........................................................... 515

Tom Dearlove, Ed Hagerman - GM R&D Center

UNDERGRADUATE EDUCATION IN COMPOSITE MATERIALS .................... 549

James M. Whitney - University of Dayton

WORKSHOP PRESENTATIONS

TEACHING WITH SIMULATION .......................................... 583

Tom Carlisle - Sinclair Industrial Engineering Technology Department

PROGRAMMABLE POWDER PREFORM PROCESS (P4) WORKSHOP:

DEVELOPING LOW COST COMPOSITES .............................. 591

Mike Melton, Scott Reeve, Correen Schneider

VACUUM ASSISTED RESIN TRANSFER MOLDING (VARTM) FOR

FABRICATION OF BRIDGE DECKS AND OTHER STRUCTURAL

APPLICATIONS ........................................................ 599

Presented by Mike Murton - National Composite Center

X
REVIEWERS FOR NEW:UPDATE 2000

Else Breval

Senior Research Associate

Materials Research Laboratory

The Pennsylvania State University

Witold Brostow

Professor of Materials Science

Center for Materials Characterization

University of North Texas

L. Roy Bunnell

Southridge High School

William Callister

Adjunct Professor of Metallurgy

University of Utah

James Clum

Director, Center for Industrial & Manufacturing Engineering

University of Detroit, Mercy

Wayne L. Elban

Professor of Engineering

Loyola College, Maryland

Mark Palmer

Assistant Professor of Mechanical Engineering

Virginia Commonwealth University

Ransom Douglas

Assistant Professor Industrial Technology

Norfolk State University

Technical notebooks were provided by

NASA LANGLEY RESEARCH CENTER

Announcements of the workshop were provided by

The ASM International Foundation

xi
TheNewEMSET2 CDROMfrom

JimJacobs, AIMcKenney and

Prentice Hall Publishing

The CD ROM Experiments in Materials Science, Engineering and Technology 2 (EMSET2) will be

available soon!

For more than a decade, the National Educators' Workshops have enabled educators to participate in

seminars of peer-reviewed experiments and demonstrations in materials science, engineering and

technology. Following each workshop, these papers were published in an annual compendium, with the

generous support of NASA.

Now, with the assistance from NASA and many other governmental, educational and industrial

organizations, we have been able to publish thirteen yearly volumes of these papers in an easily used

format, the EMSET2 CD ROM. This is an expanded and updated version of the original EMSET CD ROM.

This new version runs on all platforms and uses the universally-accepted Adobe Acrobat format for

retrieval, display and printing.

To help the user, the nearly 350 experiments and demonstrations are indexed under the following seven

categories: 1)Structure, Testing and Evaluation, 2)Metals, 3)Polymers, 4)Ceramics, 5)Composites,

6)Electronic and Optical Materials, and 7)Materials Curriculum. The user can find the material he or she

wants by browsing the tables of contents or by searching for author, title, institution, or key word. Then

the documents can be reviewed and used by displaying an exact image of the paper(s), including text,

graphs, pictures, formulae, etc. or by printing the paper as written or even by copying the text and/or

graphics into a word processor for editing.

To preview an individual demo version (available Summer 2000) please reference ISBN 0130194751 and

contact:

Melissa Orsborn

Marketing Assistant

445 Hutchinson Ave. Fourth Floor

Columbus, Ohio 43235

1-614-841-3622

McIissa_Orsborn_renhaII.com

Or

To purchase the complete EMSET2 CD ROM (available Summer 2000) please reference ISBN 0130305340

and contact:

Prentice Hall Customer Service

1-800-922-0579
xiii

NATIONAL EDUCATORS' WORKSHOP 2000

PARTICIPANTS

Harvey Abramowitz

Department of Engineering

Purdue University - Calumet

2200 169th Street

Hammond, IN 46323

219-989-2473

harveya@calumet.purdue.edu

Wade Adams

Chief Scientist

AFRL/MLBC

2977 P Street, Suite 1

Materials and Manufacturing Directorate

Air Force Research Laboratory

Wright-Patterson Air Force Base

Ohio 45433

937-255-6825

wade.adams@afrl.af.mil

Loft Aldridge

Northwestem High School

2503 W. Main Street

Rockhill, SC 29732

803-547-0969

111516@aol.com

Ronald B. Bucinell

Union College

Department of Mechanical Engineering

Schenectady, NY 12308

518-388-6023 (Pat 6264)

bucinelr@union.edu

Robert Berrettini

209 Kenmar Drive

Monroeville, PA 15146-1717

412-373-7975

berrettini@juno.com

L. Roy Bunnell

6119 W. Willamette

Kennewick, WA 99336

509-734-3800

Bunnro@ksd.org

W. Richard Chung

Department of Chemical and Materials Engineering

San Jose State University

San Jose, CA 95192-0082

408-924-3927

wrchung@email.sj su.edu

Michelle Churma

Prentice-Hall, Inc.

445 Hutchinson Avenue 4th floor

Columbus, OH 43235

614-841-3636

Michelle_..Churma@prenhall.com

Michael A. Czayka

Kent State University

3325 West 13th Street

Ashtabula, OH 44404

440-964-4266

czayka@astabula.kent.edu

Jai N. Dahiya

Physics Department

Southeast Missouri State University

One University Plaza

MS 6600

Cape Girardeau, MO 63701

573-651-2390

dahiya@physics.semo.edu

Tom Dearlove

GM R&D Center

MC: 480-106-316

30500 Mound Road

Warren, M! 48090-9055

810-986-1267

thomas.j.dearlove@gm.com

Jeane Deatherage

Administrator,Foundation Programs

ASM International Foundation

Materials Park, OH 44073-0002

1-800-336-5152

jdeather@asmintemational.org

Efremfon Frank Ekpo

Bethune-Cookman College

640 Dr. M. M. Bethune Blvd.

Daytona Beach, FL 32114

904-255-1401 ext. 532

ekpoe@cookman.edu

Wayne L. Elban

Loyola College

4501 N. Charles Street

Baltimore, MD 21210

410-617-2853

welban@loyola.edu

xv
JohnElwood

ClaflinCollege

400MagnoliaStreet

Orangeburg, SC29115

803-535-5242

AkbarEslami

ElizabethCityStateUniversity

TechnologyDepartment

ElizabethCity,NC27909

252-335-3441

aeslami@mail.ecsu.edu

DonL. Evans

Director,CenterforResearchonEducation

in Science,Math,Engineering, & Technology

ArizonaStateUniversity

Tempe,AZ 85287-5006

480-965-5350

devans@asu.edu

DanielEylon

ProfessorandDirector

GraduateMaterialsEngineering

Universityof Dayton

300CollegePark

Dayton,OH45469-0240

937-229-2551

eylon@notes.udayton.edu

NedaS.Fabris

Mechanical Engineering

CaliforniaStateUniversity,LosAngeles

5151StateUniversity

LosAngeles,CA90032

213-343-5218

nfabris@exchange.calstatela.edu

LeonardW.Fine

Department of Chemistry

ColumbiaUniversityin the

Cityof NewYork

HavemeyerHall

NewYork,NY 10027

212-854-2017

fine@chem, columbia,edu

MichaelFreed

AdvancedIntegratedManufacturingCentr

MortonFriedman

ColumbiaUniversity

500West120thStreet

Room510Mudd

NewYork,NY 10027

212-854-2986

friedman@columbia.edu

xvi

JamesE.Gardner

TechnicalStaffAssistant

NASALangleyResearchCenter

Building1219,Room217

MS118

Hampton,VA 23681-0001

757-864-6003

j.e.gardner@larc.nasa.gov

DennisGerdeman

Universityof Dayton

MarkGlasper

Directorof Communications

TheAmericanCeramicSociety

P.O.Box6136

Westerville,OH43086-6136

614-794-5898

mglasper@acers.org

RichardB.Griffm

Department of MechanicalEngineering

TexasA&M

CollegeStation,TX 77843

409-845-9779

rgriffm@mengr.tamu.edu

WilliamGrissom

CentralStateUniversity

ManufacturingEngineeringDept.

1400BrushRowRoad

Wilberforce,OH45384

EdHagerman

GM R&DCenter

30500MoundRoad

Warren,MI 48090-9055

SteveHelba

PrenticeHall

445HutchinsonAvenue

Columbus,OH43235

800-228-7854

Steve__Helba@prenhall.com

GaleA. Holmes

PolymersDivision(854)

PolymersBuilding(224),RoomB116

NationalInstituteof StandardsandTechnology

100BureauDrive,Stop8543

Gaithersburg, MD20899-8543

301-975-5280

gale.holmes@nist.gov
James A. Jacobs

Norfolk State University

700 Park Avenue

Norfolk, VA 23504

757-823-8109

jajacobs@.nsu.edu

H. Jain

Department of Materials Science and Engineering

Lehigh University

5 East Packer Avenue

Bethlehem, PA 18015-3195

610-758-4217

hj00@Lehigh.edu

Isha H. Jain

Student

Peter Joyce

U. S. Naval Academy

590 Holloway Road

Annapolis, MD 21402

410-293-6533

pjoyce@usna.edu

Alan K. Karplus

Department of Mechanical Engineering

Western New England College

Springfield, MA 01119-2684

413-782-1220

akarplus@wnec.edu

Stephen K. Kennedy

RJ Lee Group, Inc.

350 Hochberg Road

Monroeville, PA 15146

724-325-1776

skennedy@rjlg.com

Thomas F. Kilduff

504 Brafferton Circle

Hampton, VA 23663

757-857-0272

tkilduff@whro.net

Don Klosterman

Laboratory for Research on Electron

Beam Curing of Composites

University of Dayton

300 College Park

Dayton, OH 45469-0131

937-229-2517

Don.Klosterman@notes.udayton.edu

°°

XVll

Steve Krause

Dept. of Chemical and Materials Engineering

Arizona State University

Tempe, AZ 85287-2050

skrause@asu.edu

Diana P. LaClaire

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-9072

dplaclaire@nsu.edu

Louis A. Luedtke

National Composites Center

2000 Composites Drive

Kettering, OH 45420

937-297-9512

lluedtke@compositecenter.org

P. K. Mallick

Department of Mechanical Engineering

University of Michigan.-Dearborn

Dearborn, MI 48128

313-593-5119

pkm@umich.edu

John Marshall

University of Southern Maine

John Mitchell Center

Gorham, ME 04038

207-780-5447

jmarshal@usm.maine.edu

James V. Masi, Director

Northeast Center for Telecommunications

Technologies

One Federal Street

Springfield, MA 01105

413-731-3155

masij @email.msn.com

Seaton McLennan

Linn Benton Community College

6500 SW Pacific Blvd.

Albany, OR 97321

541-917-4630

mclenns@ml.lbcc.cc.or.us

Robert A. McCoy

Mechanical Engineering Department

Youngstown State University

Youngstown, OH 44555

330-742-1736

ramccoy@cc.ysu.edu
Alfred E. McKenney

516 Fairfax Way

Williamsburg, VA 23185

757-221-0476

aem2@prodigy.net

Mike Meier

University of Califomia Davis

Department Chemical Engineering

Science

Davis, CA 95616

530-752-5166

mlmeier@ucdavis.edu

& Materials

Mike Melton

National Composite Center

Vijay Modi

Columbia University in the City of New York

240 SW Mudd

New York, NY 10027

modi@columbia.edu

Pablo E. Montemartini

University of North Texas

Materials Science Department

Denton, TX 76203-5310

pmontema@yahoo.com

Robert L. Mort

University of Dayton

Engineering Technology

300 College Park

Dayton, OH 45469-0249

937-229-2685

Robert.Mott@notes.udayton.edu

Mark Murton

National Composite Center

2000 Composite Drive

Kettering, OH 45420

937-297-9528

Mmurton@CompositeCenter.org

B. Ramakrishna

Center for Solid State Sciences

Arizona State University

Tempe, AZ 85287-1704

480-965-6560

bramakrishna@asu.edu

Alessandro Rengan

Central State University

Manufacturing Engineering Dept.

1400 Brush Row Road

Wilberforce, OH 45384

937-376-6429

arengan@csu.ces.edu

Heidi R. Ries

Air Force Institute of Technology/ENR

2950 P Street, Bldg. 640

Wright-Patterson Air Force Base, OH 45433-7765

937-255-3636 ext. 4544

Heidi.Ries@afit.af.mil

Thomas E. Roberts

Milwaukee Area Technical College

700 W. State Street

Milwaukee, WI 53233

414-297-7280

robertte@matc.edu

Bill Ross

Muskegon Community College

221 S. Quarterline Road

Muskegon, MI 49442

616-777-0367

rossb@muskegon.cc.mi.us

Scott Reeve

National Composite Center

Merrill Rudes

Energy Concepts, Inc.

595 Bond Street

Lincolnshire, IL 60069

847-821-1900 ext. 312

ecisales 1@aol.com

Tony E. Saliba

Professor and Chairman

Chemical and Materials Engineering Dept.

University of Dayton

Dayton, OH 45469-0246

937-229-2627

Tony.Saliba@notes.udayton.edu

Correen Schneider

National Composite Centr

2000 Composite Drive

Kettering, OH 45420

937-297-9521

cschneider@compositecenter.org

xviii
RaoulSchroeder

BowlingGreenStateUniversity

Physics& AstronomyDept.

104OvermanHall- RidgeStreet

BowlingGreen,OH43403

419-372-8785

raoul@kottan-labs.bgsu.edu

Kurt C.Schulz

KhouryHall

Universityof thePacific

Mechanical EngineeringDepartment

3601PacificAvenue

Stockton,CA 95211

209-946-3081

kschulz@uop.edu

KathySchweinfurth

Wright,PattersonAir ForceBase

Educational OutreachOfficeCoordinator

AreaB.,Bldg.45,Room01

WrightPattersonAir ForceBase,OH45433

937-255-0692

Kathleen. Schweinfurth@wpafb.af.mil

Mike Shuman

Kent State University

Electron Beam Technology Program

NEO Beam

P. O. Box 1028

Middle field, OH 44062

440-632-1780

mshuman@kent.edu

Ram N. Singh

St. Louis Community College at Flo. Valley

3400 Pershall Road

St. Louis, MO 63135-1499

314-595-2311

rsingh@stlcc.cc.mo

Karla Strong

AFRL/MLBC

2941 P Street

Wright-Patterson Air Force Base

OH 45433-7750

Donna C. S. Summers

University of Dayton

Industrial Engineering Technology

300 College Park Drive

Dayton, OH 45469-0249

937-229-2974

dsummers@engr.udayton.edu

xix

Katie E. G. Thorpe

AFRL/MLBC

Wright-Patterson Air Force Base

OH 45433

katie.thorp@afrl.af.mil

Tia Benson Tolle

AFRL/MLBC

2941 P Street, Room 136

Wright-Patterson Air Force Base

Oh 45433-7750

Tia.BensonTolle@wpafb.af.mil

Bruno Ullrich, Assistant Professor

Dept. of Physics & Astronomy

Center for Materials Science

Bowling Green State University

Bowling Green, OH 43403-0224

419-372-7245

bruno@newton.bgsu.edu

Carlos E. Umana

Department of Materials

School of Mecanical Engineering

University of Costa Rica

San Pedro, Costa Rica

506-207-4548

caruma@terraba.ring.ucr.ac.cr

Curtiss E. Wall

Norfolk State University

700 Park Avenue

Norfolk, VA 23504

757-823-9571

cewall@nsu.edu

James W. Watson

Senior Research Engineer

A. K. Steel Corp.

Middletown, OH

513-727-5832

Jay_Watson@aksteel.com

James M. Whitney

Dept. of Civil and Environmental Engineermg

and Engineering Mechanics

University of Dayton

300 College Park

Dayton, OH 45469-0243

937-229-3847

James .Whitney@notes .udayton.edu
Edward L. Widener

Purdue University

Knoy Hall 119

West Lafayette, IN 47907-1317

765-494-7521

elwidener@tech.purdue.edu

August Witt

Massachusetts Institute of Technology

77 Massachusetts Avenue, Room 13-4138

Cambridge, MA 02139

617-253-5303

afwitt@mit.edu

Debbie Yamell

Prentice Hall/Pearson, Education

5H084

One Lake Street

Upper Saddle River, NJ 07458

201-236-7805

debbie__,yamell@prenhall.com

xx,
PROFESSOR

Robert Mott - University of Dayton

STUDENTS' NAMES

James Coleman

Jason Glock

Carolyn Gudaitis

Tim Hague

Ben Lambers

Brian Noel

John Rowland

Lynn Stonebrook

Zach Williams

PROFESSOR

Robert Chasnov - Cedarville University

STUDENTS' NAMES

Torrey Wycliffe Adams

Charles P. Aman

Lindy A. Anderlini

John Thomas Bailey

Andrew L. Bennett

Ehren Duane Bfinkrneier

Jonathan Samuel Brockman

Joseph S. Burke

Bradford Wesley Desatnik

David James Drye

Lance Everett Ferguson

Nicholas A. Forshee

Nicholas Edward Grisco

William Hamilton Jenks

Jared M. Koverman

Jeremy Alan Mailer

Kenneth L. Mansfield

Timothy John McCorkle

Kenneth Jay Moore, Jr.

Stephen C. Moseley

Matthew Paul Nealis

Bradley Eugene Nicol

Steven Mikel Page

Stephen Wesley Parker, Jr.

Christopher Recktanwald

Francis Wingate Saul III

Andrew Douglas Schmidt

Cameron James Stephan

William John Walker

Brian Maris White

David P. Wolf

Adam J. Yingling

xxi

NATIONAL EDUCATORS' WORKSHOP

Update 2000: Standard Experiments

in Engineering Materials, Science,

and Technology

October 29 - November 1, 2000 - Kettering, Ohio

Sponsored by

Department of Energy

Office of Energy Efficiency and

Renewable Energy

School of Science and Technology

Norfolk State University

Air Force Research Laboratory

Materials and Manufacturing Directorate

Wright-Patterson Air Force Base

_ TheASM

International

Fotnxt,xi_

The ASM International Foundation

National Composite Center

IvISEL.

Materials Science &

Engineering LaboratoriesNIST

USAMP

United States Automotive

Materials Partnership

DAYTON

University of Dayton

National Aeronautics & Space

Administration

Langley Research Center

Energy Efficiency and Renewable

Energy Program

Oak Ridge National Laboratory

Center for Lightweight Materials

and Preeessing

University of Michigan - Dearborn

Gateway Engineering Coalition

with the support of

Advanced Integrated Manufacturing Center

Columbia University

Edison Welding Center

Gottschliek & Portune

International Council for Materials Education

Mead World Headquarters

Reynolds & Reynolds

American Society for Engineering Education

Dayton Power & Light

Fifth Third Bancorp

Hardcore Composites Operations LLC

McDonald Investments (Ke3t Bank)

Northeast Center for Telecommunication Technologies

Wright State University

xxiii
xxiv
WELCOME

OPENING SESSION

Jim Jacobs

XXV
OPENING SESSION

Louis A. Luedtke

National Composite Center

Heidi R. Ries

Wright Patterson Air Force Base

xxvi
REGISTRATION

Diana LaClaire

xxvii
NATIONAL COMPOSITE CENTER STAFF

6*4

XXVII1
SESSIONS

xxix
SESSIONS

(continued)

XXX
SESSIONS

(concluded)

xxxi
BREAKS

Jim Gardner and Bob Berrettini

xxxii
XXX111
University of Dayton

xxxiv
BRIDGE BUILDING

AI McKenney and Alan Karplus

XXXV
BRIDGE BUILDING

(concluded)

A1 McKenney

xxxvi
MINI WORKSHOPS

PROGRAMMABLE POWDER PREFORM PROCESS

Demonstration - hands-on project. A review of the

process for producing high volume, net shape

preforms for structural composites at the

National Composite Center

Presented by Mike Melton, Scott Reeve, Correen Schneider

National Composite Center

COMPOSITE MATERIALS LABORATORIES

Characterization, properties testing, electron beam

curing, and rapid Prototyping of complex-shaped

composite at University of Dayton Research

Institute Composite Research Facility

Presented by Dennis Gerdeman

University of Dayton

VIRTUAL ENGINEERING

Overview of the range of virtual engineering

tools and processes employed by the AIM Center

to improve manufacturing performance and

productivity at the AIM Center

Presented by Michael Freed

The Advanced Integrated Manufacturing Center

COMPOSITES LAY-UP AND TESTING AT THE

AIR FORCE RESEARCH LABORATORY

Hands-on composite fabrication, characterization, and

testing at the Materials and Manufacturing Directorate

of the Air Force Research Laboratory

Presented by Katie E. G. Thorpe

AFRL/MLBC Wright-Patterson Air Force Base

VACUUM ASSISTED RESIN TRANSFER MOLDING (VARTM)

FOR FABRICATION OF BRIDGE DECKS AND

OTHER STRUCTURAL APPLICATIONS

A demonstration of the composite

bridge deck construction program in Ohio

Presented by Mark Murton

National Composite Center

xxxvfi

EDUCATIONAL OUTREACH AT

WRIGHT-PATTERSON AIR FORCE BASE

Kathy Schweinfurth

Wright-Patterson Air Force Base

Educational Outreach Office Coordinator

Area B., Bldg. 45, Room 01

Wright-Patterson Air Force Base, Ohio 45433

Telephone: 937-255-0692

e-mail Kathleen. Schweinfurth @wpafb.af.mil
: Kathy Schweinfurth
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PROGRAMMABLE POWDER

PREFORM PROCESS (P4)

Correen Schneider

National Composite Center

2000 Composite Drive

Kettering, Ohio 45420

Telephone: 937-297-9521

e-mail cschneider @ compositecenter.org

19
Correen Schneider

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40
EXPERIMENTS IN LIQUID CRYSTALS:

DIFFERENT STATES AND DEVICES

James V. Masi

Director

Northeast Center for Telecommunications Technologies

One Federal Street

Springfield, Massachusetts 01105

Telephone 413-731-3155

e-mail masij @email.msn.com

41
James V. Masi

42
Experiments in Liquid Crystals: Different States and

Devices

James V. Masi

Northeast Center for Telecommunications Technologies

Springfield, MA 01105

(413)731-3155, FAX (413)734-0515

masi@ stcc.mass.edu

Abstract:

A thermotropic liquid crystalline state occurs in certain materials, in a temperature region

between the solid and liquid (isotropic) states. The material in this region possesses some

properties of both liquids and solids. The anisotropies of this liquid crystal (L.C.) material gives

it some of the most interesting, beautiful, and useful devices, challenged only by nature itself.

This set of five experiments shows the electrical, thermal, magnetic, optical, and

mechanical properties and anomalies responsible for the useful effects and devices resultant

from these materials. From soap to thermometers, from displays to filters, from acoustic to nonlinear devices, liquid crystals and the experiments one can easily do will make this experience a

useful and entertaining one. Demonstrations, hands-on tests, and samples will be included in

these experiments

Key Words: Liquid crystals, displays, thermotropic, nematic, liquid crystal polymers.

Prerequisite Knowledge: The student should be familiar with the basics of materials science,

metallography, and chemistry. Levels at which these experiments are performed are second

semester junior year and either semester senior year. The students are first given lectures the

properties of materials including organic liquid crystals and polymer liquid crystals (PLCs).

They should have already had a laboratory experiment on metallography and sample preparation.

Objectives: The objectives of these experiments'are to show how the unique properties of liquid

crystals lend themselves to applications involving thermal, electrical, magnetic, and optical

properties and how they are incorporated in a variety of devices. These experiments contain all

of the elements of good design, with the caveat that a novelty in structure is sometimes a part of

design. The students learn the process of designing materials for the world of

telecommunications, analyze those already used, and suggest possible solutions to the problems

involved with present technology.

Equipment and Supplies:

(1) Metallurgical preparation and polishing apparatus (eg. Buehler Co., Port Washington, NY).

(2) Varieties of liquid crystal chemicals (Roche Chemical Div., Hoffmann-LaRoche Inc., Nutley,

NJ; Baker Chemical, Licristal Materials.)

(3) Low voltage 60Hz power supply, Polarizers, 1⁄4 wave plates (Edmund Scientific)

43
(4) Miscellaneousgraduates,glassware,ovens (Fisher Scientific),

(5) Indium-tin oxide coated glass and plastic (Tecknit Corp., Cranford, NJ)

(6) Miscellaneous meters and power supplies.

(7) Metallurgical microscope (Olympus, Zeiss, etc.).

(8) Liquid crystal displays (LCD Planar Optics, Farmingdale, NY)

Introduction:

Liquid Crystal Materials

In the process of forming crystalline solids, organic materials (anthracene, camphor, etc.)

exhibit long range ordering. Their molecular centers are set on a repetitive lattice. These

molecules also have a definable orientation with respect to the rest of the lattice. Usually, when

compounds such as these melt, they form an isotropic liquid, losing most of their long range

(over two molecules) order and, in large part, any of their orientation properties that they had as

a solid. Less than 0.5% of all organic compounds have a range of temperatures and conditions

where they exhibit an state which is intermediate to the crystalline solid and the isotropic liquid.

This state is called their "liquid c_stal'" state. Long-range order is maintained for a range of

temperatures below the melting point. Compounds such as MBBA (p-methoxybenzilidene pbutyl aniline, an early SchiffBase material), shown in Figure 1, have alternate double and single

bonds in a rigid, elongated structure and tend to form liquid crystals.

and choles_eryl acetate

CR(Me_.CH2.CR2.CH2oCII.He2

Me

MeCO,O 14.e_

Figure 1. MBBA Liquid Crystal Material

This particular material, when mixed in eutectic composition with EBBA (p-ethoxybenzilidene

p-butyl aniline) form an electrically active material which is a liquid crystal over a range of 0 oc

to 55 oc. When an electric field is applied across these materials, they change from clear to

milky white. These are called dynamic scattering materials (named after the hydrodynamic

turbulence caused by the electric field influence). The resultant properties of these materials and

other liquid crystal materials in other classes, such as esters and biphenyls, are quite unusual.

The unique properties and the control of the chemistry leading to these properties make these

methods excellent teaching and learning tools. A typical schematic of liquid crystal types is

shown in Figure 2. At Western New England College and the Northeast Center for

Telecommunications Technologies, laboratories have been developed involving four distinct

44
properties (and chemicals) of liquid crystal materials 1. An overview of liquid crystal materials

and properties 2 is given in the Appendix for use as a pre-lab lecture or as reference for the

student and laboratory instructor.

_olid 4_ LiQuid Cfyl;tOt

Temperoture

_lsotroplc L_ quiet

_:_ e_. %.-'J "_ _',l _

Isolropi¢ l. iq uL "_

_ " _.'7._"-/0 "-_'_ .0 _ _ ,_.'_ ,,

Cholel ter|c

V,O vU

U u

o2od OOoUo u o

nuO0 0u_00v0a

"0000.0_ 0 -0_

Nemoti¢

Figure 2. Types Of Liquid Crystals and Temperature dependence

Procedure:

The specific aims of these experiments are to classify the mechanisms of liquid crystal

chemistry, optical electric, thermal, and magnetic properties and devices, and to compare the

results with theory. There are four experiments that the student should perform. The first is the

observation of dynamic scattering in liquid crystals_; the second is a cholesteric color

temperature indicating cell; the third is the fabrication and test of a liquid crystal light valve; and

the fourth is a color cell produced by using polarization and quarter wave interference _.

Experiment 1: Observation of Dynamic Scattering in Liquid Crystal Cells

In the dynamic scattering cell, there is no need for "anchoring" the molecules on either

side of the ITO (indium tin oxide) coated glass (see experiment 3). The fabrication procedure is

simple, consisting in obtaining indium tin oxide coated glass plates (e.g. Tecknit Corp), Mylar

spacers, and epoxy sealers (Figure 3).

45
/

$n02 coated gloss

.,/

._dar_e up ce;;

Celt con_itructic:n

Figure 3. Schematic representation of cell construction

Once the cell is filled with the dynamic scattering liquid crystal material and the cell is sealed

(see Appendix), the cell is ready for observation and test.

1. Place one of the metered a.c. supply terminals on one of the extended ITO electrodes,

and place the other on the electrode of the opposite ITO coated glass.

2. Observe both macroscopically and microscopically, noting visibility vs angle of view.

3. Take observations (photometric if available) and measure either backscatter from

ambient or transmitted light vs voltage. Plot Transmission vs voltage (RMS).

4. The observations are taken to the point where hydronamic turbulence occurs.

5. Observations should correspond roughly to those shown in the Appendix.

Experiment 2. Cholesteric temperature indicating cell

This experiment shows the pitch change of the cholesteric L.C. with temperature.

1. Take a clean piece of white polypropylene or polyester plastic (approximately 2 cm. x 4 cm.

x 1 mm.) and a piece of clear polyester of the same size.

2. Place a drop ofa cholesteric L.C. (e.g. cholesterol nonanoate) onto the white plastic in the

center.

3. Take the clear polyester and place it onto the white plastic with the L.C. and seal the edges,

making sure to press the L.C. material to a uniform thickness.

4. Take the sealed cell and place it onto a large aluminum block (10 cm. x 10 cm.) along with a

surface thermometer (Fisher Scientific) and register the temperature of the block vs. the color of

the cholesteric liquid crystal sandwich.

5. Discuss the construction of a wide temperature range L.C. thermometer.

Experiment 3. Fabrication and test of a nematic liquid crystal light valve

Fabrication of the nematic light valve involves the observation of birefringence change

under the influence of an electric field (see Appendix).

46
1. Constructa light valve with nematic L.C. material as in experiment 1, with the added step of

surface alignment on each side of the ITO coated glass (Appendix).

2. After sealing the cell, no macroscopic changes will be noted with the application of 2-4 volts

d.c., due to the higher resistivity of the material and the fact that only the director (index of

refraction) changes with field application.

3. Now place the cell onto a light table or place a light source behind the cell, and place a

polarizer on either side of the cell, either parallel or perpendicular to each other's axis (Figure 4).

I_ltml ¢:_t

E:l,maerga • _ ....... _ ....

_._

Figure 4. Nematic L.C. Cell

4. Measure transmission vs voltage and transmission vs frequency (signal generator) for this

cell. Also measure transmission vs angle of view.

5. _ raise the temperature of the cell on a hot plate and observe the nematic to isotropic

transition temperature. Allow it to cool and watch the reversal.

Experiment 4. Color nematic quarter wave interference cell

This experiment shows the other side of birefringence, namely color.

1. Take the cell made in experiment 3, along with its polarizers.

2. Place a quarter wave plate at 45 degrees to the polarizer optic axis on either side of the

sandwich and place the assembly on the light table.

3. Turn the light valve "on" (i.e. 3-5 v.d.c.) and observe the color of the cell vs the angle of one

of the quarter wave plates as it is rotated.

4. Explain the mechanism responsible for this phenomena.

Comments:

These experiments exhibit some of many possible electro-optic and magneto-optic

effects in liquid crystals. They demonstrate how to obtain either scattering or birefringence

changes, the latter giving optically observable effects when the cell is placed between polarizers.

Appendix: Liquid Crystals 2

Anisotropy

Although the properties of its constituent molecules are usually anisotropic, a normal

liquid exhibits isotropic behavior due to spatial and temporal averaging and best-fit charge

47
compensation. In a liquid crystal, orientational order exists over distances of many micrometers,

and their macroscopic properties are anisotropic. Figure A1 shows the way in which molecules

might be arranged in a normal liquid and in a liquid crystal. A preferred direction (or director)

in a normal liquid does not exist, but one does in a liquid crystal. The interactions between liquid

crystals and light, electric and magnetic fields, X-rays, diffusing species, and the like, are

dependent on the angle between the impressed forces and the director.

/ /

I\/ __.

I f," I _/"

\ I / _--'/J I

,1 / -"

// t \i \/ /

i/ -11 /

Director

/ "-..

1tl,////1

\_"_ \ lilt t _1////

"'_\_ii,t/t//,/./

fi / •

,,, ',01s/:/

Normal Liq.i0 Liquid Crystal

Figure A1. Normal Liquid and Liquid Crystal

Response to an applied field

Both normal liquids and molecules in a liquid crystals respond to applied magnetic and

electric fields. Electric field induced molecular alignment (5-30%) in normal liquids (Kerr

effect) results from th.e couple exerted on permanent and induced dipoles by the applied field in

the presence of thermal agitation. In liquid crystals, the effect is two orders of magnitude greater

because all the molecules move together. Because of this, a field of 106 V/m induces virtually

100% alignment.

Large liquid crystal displays can be fabricated

By anchoring the molecular orientation at the surfaces of a thin crystal layer it is possible

to create a single crystal with a thickness up to about a hundred microns. Only the molecular

alignment is unique, the positions of the centers of the molecules change with time.

Liquid Crystal Types

The primary types of liquid crystals are shown in figure A2. They are as follows:

Nematie. Positional order is completely absent but the rod like molecules try to lie parallel to

one another. Only molecules that are separated by several tens of micrometers show any

significant departure from parallel alignment. Some Schiffbases, esters, and biphenyls exhibits

a nematic liquid crystalline phase.

48
!_r4%__ /

neme_, _ smecUc-_ smectic-C

_nd cholestedc. Chemi_sl s_ucture of three

t;o,_l-r..r,n_ molecule_ is Shown:

,e.m_ber_er_v_e has hemal.

.snnec_A, and leme_ar cryst_lne sme_tic_6

p_esem _ct,_-cy_,_oblphe_ hss a

nemsticph_so end a smectio.A phe_e (in the

m _ _.4 _ the m_l_Jl_r le_l_,

whk_ ind_atM molecules are p_md

mrra_y m the _vO _mown he_e);

chales_eral nonanaele is _plcet

: of Ille chiral moieties that h_vs &

cho!este_ ph_e_

_:_!_ .._!._ _:!_ -_,

/////////m

/ Elm

g gg

T_ r_e_ _ _._n._

Gh_e_

Cho!ostemlP,onennete

Figure A2. Types of Liquid Crystals 3

Smeetic. There are several smectic types all of which exhibit the same tendency for molecular

parallelism in all 3 dimensions. Smectics have a layered structure due to the tendency for the

molecular centers to lie in well-defined planes. The director may or may not be normal to these

planes and the centers may be random within the planes or may have varying degrees of order.

Smectics, have high viscosity, and are sometimes used for memory additives for nematic

crystals. By the way, smectic liquid crystals were originally used as alignment agents in

detergents, due to their anisotropy.

Cholesterie. This liquid crystalline state occurs when the molecules are planar rather than rodlike. Thus, the molecules may stack parallel within one plane but may lie at a well defmed angle

to one another along' the normal to that plane. The structure is much like a nematic that has been

twisted about the normal to the director. The pitch of the helical structure is a function of

temperature, molecular type, and they often exhibit "chromatic" effects due to their layered

pitch.

Optical Properties

The most obvious consequence of anisotropy is the highly refractive and sometimes

turbid optical effects of liquid crystals in bulk form. The angle between the director and the light

beam varies spatially and with the passage of time. As a result, the light is steered by the

49
refractive index variations and there is strong scattering away from the incident direction

although very little light is backscattered. In nematics, the material is locally uniaxial, and the

optical axis is parallel to the director. As expected, there are the usual birefringent or doubly

refractive properties. In cholesterics, the symmetry axis is the helical axis so that optic axis and

director are normal to one another. In addition to birefringence there are optical rotary effects.

Alignment and patterns

In the case of a thin (10-100 _tm) liquid crystal layer contained between two ITO coated

glass plates, surface treatment (coating with PVA or polyimide and rubbing unidirectionally) of

these plates can lead to a stable well defined director orientation throughout the layer. Figure A3

shows orientation of the liquid crystal molecules perpendicular or parallel to the plane of the

container walls. Cholesteric liquid crystals can only sustain a unique orientation when the

director is in the plane of the glass surfaces. Then, the helical (optic) axis is normal to the

surfaces and there are considerable optical effects along this axis. The structure, called

Grandjean, is unique, it being impossible to achieve any other arrangement by surface control:.

Cholesterics frequently take up a structure in which short helical sections are packed in a more

complicated, strongly scattering state which, although not fully stable can survive for long

periods.

Z,_ro fi_l,(l &tafe_i #f _"iol_ilTriCs (tRiJ itOf'i_OflC_.

Figure A3. Orientation of liquid crystal molecules at the substrate: (a) homeotropic or normal;

(b) non-aligned; and (c) homogeneous or parallel alignment.

Response to electric fields

When the liquid crystal resistivity is very high (> than 1012 ohm-cm) and only dielectric response

is involved, the applied field acts on both permanent and induced dipoles. The molecules have

axial symmetry so that when the polarizability is greater parallel to the axis than perpendicular to

it, the molecules align parallel to the field in order to minimize the energy as shown in Figure

A4. For materials with greater polarizability across the

50
(a)

(b)

Liquid

Polyim ide

(d)

Figure A4. Liquid crystal alignment in an electric field 4

molecular axis, the director aligns perpendicular to the applied field. The difference between the

polarizabilities is expressed in the dielectric anisotropy (e//- e±), being positive when the parallel

component is greater. The anisotropy usually seen in data sheets is for low frequencies and it

should be remembered that it may diminish or change sign at frequencies above 5-10 kHz.

The addition of significant charge transport leads to a more complicated response. Fig_r2e- A5

illustrates the response of a nematic liquid crystal, with relatively low resistivity, (<10 2 ohmcm) and significant negative low frequency dielectric anisotropy. In zero field, surface control is

used to set the director at right angles to the surfaces (parallel to the applied field). At a few

volts, an applied field acts on the dielectric anisotropy and over most of the film, the director

aligns perpendicular to the applied field. This situation is shown in Figure A5. As the applied

field is increased, significant current is passed. Any distortion of the director, such as may be

caused by thermal or vibrational effects, leads to a sideways displacement of charge due to the

conductivity anisotropy. As indicated, this provokes an increase in the distortion and the

situation is unstable, leading to a cellular, forced convection in the liquid. The same

phenomenon may take place in a cholesteric liquid crystal with negative dielectric anisotropy. If

the anisotropy is very small and the director is initially arranged to be parallel to the field,

cellular convection may not occur. On the other hand, if the material has very weak positive

51
anisotropy and the director is initially arranged perpendicular to the applied field, cellular

convection may occur.

(a) (b) (c)

(d) (e)

Figure A5. Patterns fordynamic scattering L.C. with voltages (a) 0V, (b) 1 V, (c) 2 V, (d) 3 V,

and (e) turbulence above 4 V (RMS)

Device Fabrication

To make a crude electro-optic device, two glass plates, coated with a transparent

conductor are spaced by a 25 micrometer thick Mylar spacer which is in two parts (Figure 3).

After suitable surface treatment the plates are clamped to the spacer and are sealed together with

epoxy resin all round the perimeter of the spacer except for two small areas corresponding to

gaps in the spacer. The clamps are taken off when the epoxy has hardened and the cell is filled

in vacuum by capillary action. A drop of liquid crystal is placed near one filling hole and the cell

is placed on a tilting table in an enclosure which is rough pumped. After a suitable interval, the

table is tipped, the liquid crystal fills the cell and air is let into the enclosure. Finally, the filling

holes are sealed, care being taken to avoid contaminating the liquid crystal. This technique

allows one to use very small quantities of material.

Electro-Optic Effects

(a) Dynamic Scattering

A nematic liquid crystal material, with low resistivity and negative dielectric anisotropy,

will in general exhibit dynamic scattering. It is usual to treat the cell surfaces with lecithin or a

similar surfactant to make the director normal to the cell surfaces. An applied steady voltage of

about 2V/25 Bm swings the director round until it lies in a plane normal to the field. This

phenomenon, sometimes called the Frederiks Effect, is independent of frequency up to 50 kHz or

above (see Figure A6). Further increase in a steady or low frequency (- 50 Hz) applied voltage

52
leads to the convection, and, if this is driven beyond the streamlined flow condition, turbulence

occurs. This disrupts all structure in the nematic film, causing strong light scattering ('dynamic

scattering') which ceases when the current is reduced to zero. As shown in Figure A6, the •

dynamic scattering threshold voltage rises rapidly at the dielectric relaxation frequency which is

inversely proportional to resistivity and dielectric constant. At low frequencies, the space

charge inhomogencity which results from the conductivity anisotropy, reverses its sense in

sympathy with the applied field. The force exerted on the space charge is therefore unchanged as

the applied field oscillates but only as long as the space charge distribution can reverse

accordingly. Above the dielectric relaxation frequency, the alternating field acts on some mean

charge displacement that causes the director to oscillate about its mean position. This causes

scattering which is weak and has a threshold RMS voltage which increases as the square root of

the frequency.

(b) Twisted Nematic Light Valve

Polarizer _tass Plate

F l " f'| Tr.nsparent

electrode _lter r_ sp. 0,l-d' , f r .....[

Lkluid crysta_

(or) TWISTED NEMATtC DISPLAY

?class plates

Ed, _ka_t.. A--- Transparent

"_t_. ; ........ :- : :._ _..7..conducti,,

Liquid crystal Reflector

Figure A7.

(b) D't'NANIC SCATTERING & D'_E PHASE CI-_NC_

DISPLAYS

Construction of L.C. Valve for twisted nematic and dynamic scattering

Again a nematic liquid crystal is used, but resistivity, dielectric anisotropy and surface

preparation are all different. The resistivity is made as high as possible by material purification,

and the anisotropy is chosen to be positive. The surfaces are treated so that the director lies in the

plane of the surface and along a well defined direction. However, this direction on one surface is

arranged at right angles to the special direction on the other surface. The result is a twisted

nematic structure that has the effect of rotating the plane of plane polarized light through 90 °. A

sandwich of the cell between two crossed polarizers leads to transmission whereas a cell

between parallel polarizers leads to virtually no transmission (see Figures A4 and A7). When a

small voltage (2_V)ois applied, the director rotates until the optic axis lies along the incident light

direction. The 90 twist is lost and the transmitting sandwich becomes opaque (or the opaque

sandwich transmits). The original effect is regained when the field is switched off.

(c) Cholesteric to Nematic Phase Change.

A cholesteric with positive dielectric anisotropy and high resistivity is used. The

cholesteric is originally set in the clear stable structure with the optic axis normal to the cell

53
surfaces. An applied field aligns the molecules parallel to the field and parallel to one another.

The result is that the material is no longer cholesteric but is nematic although the film remains

clear. On removing the applied field, the cholesteric phase grows randomly throughout the film

and the result is a disordered structure that scatters light and persists for some time. The

working material canbe made from a mixture of a normal cholesteric (usually having low

anisotropy) and a high positive anisotropy nematic.

(d) Cholesteric_Memory Effect.

This effect which involves a negative anisotropy cholesteric with low resistivity can be

understood from a study of Figure A6 for dynamic scattering. The memory effect is in fact

simply dynamic scattering, but in a cholesteric, the scattering state reverts only very slowly to the

clear original structure. The optic axis is arranged perpendicular to the cell plates and so the film

starts off clear. Application of a low frequency voltage leads to disruption of the film into a

•scattering condition which can persist for months after the current is stopped. Application of an

alternating voltage above the Frederiks threshold and beyond the cut-off frequency causes a

Frederiks effect which regains the original clear structure. The device thus has one stable and

one metastabte off state and thus exhibits memory.

References:

1. T. Kountotsis, "Liquid Crystal Display Design", Western New England College Summer

Design Project, June, 1998 (present address General Dynamics, Pittsfield, MA) and B. Wilson,

"Design of Color Liquid Crystal Display System", Western New England College Senior Design

Project, June 1986 (present address AOX Corp, Dallas, TX).

2. J. Kirton., "Electro-Optic Effects In Liquid Crystals", Proc. Conf. Liquid Crystals, Kent State

Univ., 1982. pp.46-57.

• 3. J. Litster and R. Birgeneau, Physics Today, Vol. 35, No.5, 1982. pp. 26-33.

4. G. P. Crawford, SAMPE Jnl., 32, 4 1996. pp. 22-28

54
DOOR RADIUS VS OPENING FORCE

OR FREE-BODIES VS FISH-SCALES

Edward L. Widener

School of Technology

Mechanical Engineering Technology

Purdue University

1417 Knoy Hall, Room 145

West Lafayette, Indiana 47907-1317

Telephone: 765-494-7521

e-mail elwidener @tech.purdue.edu

55
Biography:

Prof. Widener has taught at Purdue University since i 978, concentrating on mechanics, materials,

recycling, and communicating. Ed was in Malaysia from April 1995 - June 1996, teaching

Metals Lab for new technology teachers. Membership_include ASEE, ASM, ASME, ISA,

TAPPI. A registered P.E. in New York & Indiana, he was ABET accreditation visitor, from

1983-1990; and NSF lab-grants reviewer in 1989 and 1990. Between 1994-1977, he had night

classes in Indianapolis, IN (ILrPUI) and Danville, IL (Jr. College). Degrees from Purdue are BS

'49 (physics) and BS '51 (ME); MSEM 62 (Hydraulics) is from University of Kansas. Between

1952-1978, Ed was a process or project engineer for Continental Group, Baker-McHenry-Welch,

Kimberly-Clark. E.I.DuPont, Union Carbide, & U.S. Steel. In WW II, he was U.S. Navy S1/c

aboard light-cruisers Vicksburg & Astoria.

Edward L. Widener

56
DOOR RADIUS vs OPENING FORCE

or Free-Bodies vs Fish-Scales

by Edward L. Widener, PE

Purdue University, MET Department

W. Lafayette, IN.

Key Words: Force, friction, gravity, inertia, moment, weight

Prerequisite Knowledge: Force=mass x acceleration; Weight=mass x gravity

acceleration; Friction=coefficient of friction x normal force; Potential energy=weigh t x

height; Kinetic energy=(1/2)(mass)(velocity squared).

Objective: To promote open-ended problem solving. To compare analytical solution

(via free-body diagram) with experimental solution (via fish-spring scale).

Equipment & Materials:

1) Fisherman's Spring Scale (Sports Dept., Wal-Mart, 28-1b capacity, $3.00).

Read to nearest quarter pound (4-oz avoirdupois).

2) Loop of String (cord or twine).

Fasten scale hook to door handle.

3) Screw Driver (if needed).

Disconnect door-closer piston.

Abstract:

New doorframes in commercial 6'hallways often are 5'x7', with 3'x7' and 2'x7'

doors, mounted side-by-side. Often the 3'door has an automatic opener, for wheelchairs

or cart clearance. Routinely we may use that 2'manual door to save energy. We assume

the pull on our light-weight door (with 2'moment arm) is LESS than on the heavier door

(with 3'moment). Your assignment (if you choose to accept it) is to PROVE IT.

Analytically, a free-body diagram (3D) involves astute assumptions of door-construction

and hinge-friction. But experimentally, a simple reading of a spring-scale showed our

3'door needed about 10% more pull than the 2'door.

Procedure:

Pulling forces can be rapidly and repeatedly read from a fisherman's spring-scale,

hooked into a door handle. Some latches may require a loop of string to hook into. Does

the pulling angle vary with wall-clearance? Does a fast pull take more force? Does a

slow pull show less fluctuation? Does a panic-bar affect the pusher force (for oncoming

traffic)?

Our scale is read to the nearest 1⁄4 lb (4-oz); it also reads kilograms (force) to a tenth.

And there is a built-in 3'steel ruler (1-metre long), read to 1/32 inch or 1-mm.

Other methods may involve a thin rubber strip (say 1/4"wide x 3'long), which is cut

from an inner-tube (in bicycle or truck tire). Holding a ruler aside the strip and reading

elongation is generally a 2-man job, assuming elastic behavior.

Other elastic bands involve white sewing-tape, with tan latex or white spandex fiber.

Typically a 1⁄4" or 1⁄2" width (1' or 2' long) provides adequate stretch. Using a thin, long,

57
rubber"tie-down" is anoption, if clearanceis noproblem).Countfloor-tiles (12" or 9"

squares)to estimatedistancesandmomentarms.

SeeFIG.I (3-D FreeBodyDiagram)

Results:

Thisplain scaleconsistentlyregistereda9-1bpull for the3'door (versus8-1bfor

2'door) with slowmotion. Disconnectingthedoor-closeror openerlevershadnoevident

effect.Oncemoving,eachdoorwaseasierto pull (about1-1bless).Of course,increasing

the door-speedorpull-angledid increasethepull force,sayanotherpound.However,our

springthenfluctuatedandaccuracysuffered;purchasingabetterscale(about$30)is

recommended.

Conclusions:

Usingthe2'door doesindeedsaveeffort(say10%)aswell aselectricpower(avoid

automaticopener)andequipmentmaintenance(leversandswitches).Clearlytheinstalled

costis lower(7 % lessdoor area;no automaticopener).But lateralclearanceis less

(33%).Safetyis enhanced(nosuddenautomaticswing).

We shouldcomparecostsof two standardautomatic3'doors,versus3'/2'combination.

In a6' hallway,this is "Value Engineering".

For globalequivalence,convertto S.I.metric architectures.

References:

1) Jacobs,J.A.,& Kilduff, T.F.,"EngineeringMaterialsTechnology",4thed.,

Prentice-Hall,ColumbusOH, c.2001.

2) Parker,S.B.(Ed.),"McGraw-Hill Dictionaryof Scientific& TechnicalTerms",5th

ed.,NYCity, c.1994.

3) Hibbeler,R.C.,"EngineeringMechanics:Statics& Dynamics",7thed.,PrenticeHall, EnglewoodCliffs NJ, c.1995.

58
STRUCTURE AND MECHANICAL

PROPERTIES OF THERMOPLASTIC COMPOSITES

W. Richard Chung

Department of Chemical and Materials Engineering

San Jose State University

San Jose, California 95192-0082

Telephone: 408-924-3927

e-mail wrchung@email.sj su.edu

59
Biography:

Prof. W. Richard Chung joined the faculty of San Jose State University in 1987. His

primary teaching responsibility is in the Department of Chemical and Materials

Engineering. He holds a Bachelor's degree in Chemical Engineering, a Master's degree

in Materials Engineering, and a Ph.D. in Mechanical Engineering. He has six years of

industrial experience in three fields: paper and pulp, plastics manufacturing, and nuclear

power plant design and construction. He also worked as a consultant for IBM, HP, Intel,

and Lockheed Martin. His research interests include failure analysis of materials, smart

composites, and failure behavior of plastics encapsulated microchips.

60
Structure and Mechanical Properties of Thermoplastic Composites

W. Richard Chung, Department of Chemical and Materials Engineering, San Jose State

University, San Jose, California 95192-0082

Abstract:

In recent years there has been an immense interest in the fiber-reinforced thermoplastic

composites. The main reasons for the interest are associated with the potential

improvements in manufacturability, recyclability, reformability, composite properties,

and work environment. The main attractions of using a thermoplastic matrix rather than a

thermosetting one are related to the ease of manufacturing and the strengths achieved in a

short time with no chemical reaction during the solidification process. In this study, glass

and graphite fibers will be used to reinforce various thermoplastic matrices such as

polyethylene, polypropylene and acrylonitrile-butadiene-styrene (ABS). Material

parameters such as stacking sequence, reinforcement orientation, and fiber volume

fraction will be varied in order to study their overall influence in mechanical properties.

A set of control samples using the same types of fibers and thermosetting polyester will

also be manufactured. A simple cost-effective compression molding technique will be

used to manufacture the aforementioned composite laminates. Custom-made composite

laminates will be machined into coupons that will be subjected to in tensile, impact, and

flexural tests. The ASTM standard testing procedures will be carefully followed.

Comparisons of mechanical properties between thermoplastic and thermosetting

composites will be addressed. Emphasis will be placed on the relationship between

structure and properties relative to material performance. The test results and failure

mechanisms will be discussed and presented to the workshop.

Key Words: polyethylene, polypropylene, ABS, thermoplastic composite, thermosetting

composite, consolidation, tensile test, impact test, and flexural test.

Prerequisite Knowledge: Basic knowledge of the difference between thermosetting

and thermoplastic polymer matrix materials relative to manufacturing methods and

mechanical behaviors.

Objectives: To understand the structure and mechanical properties of fiber-reinforced

thermoplastic composites, and how their mechanical properties compare to those of

thermoset composites,

Equipment and Materials:

1. A lamination press with temperature and pressure controls.

2. Metal molds for manufacturing composite square rods and panels.

3. Various types of thermoplastic resins (ABS, PE, PP), and a thermosetting

(polyester) resin.

4. A bucket of cold water for cooling the specimens.

Safety Precautions:

1. Safety glasses and leather shoes must be worn when working in the

laboratory.

61
.

.

.

Many chemicals, solvents, and catalysts can cause severe bums or irritation to

skin and eyes. For this reason, every effort should be made to avoid contact

with them. To prevent skin injuries, wear a pair of gloves, an apron, a shop

coat, or even an old shirt or jacket.

Dust masks must be wom at all times when working on sanding, fine

polishing, or machining of lab projects; these operations produce hazardous

debris. Respirators must be worn when working with chemical fumes such as

polyester, ABS, etc.

Thermal gloves must be wom during the process of transferring the heated

metal molds to the water bath.

Introduction:

Continuous fiber-reinforced thermoplastic composites have emerged as a fast-growing

area of the composite industry. Their excellent mechanical properties enable them to

penetrate the traditional markets of wood, metals, and thermosetting

polymers/composites. The growth rate for continuous fiber-reinforced thermoplastic

composites has been 30% per year from 1990 to 1999. [Ref.1] The major benefit of

switching from these traditional materials to the thermoplastic composites is to improve

fracture toughness, shear strength, and to reduce manufacturing cost. [Ref. 4-7] The high

market demand for thermoplastic composites is primarily driven by automotive

applications. These include integrated front ends, load floors, truck beds, instrument

panels, and integrated door panels. Based on a market overview released by the Society

of Plastics Engineers, similar large part application development is occurring in

recreation vehicles such as all terrain vehicles (ATV's), golf carts, snowmobiles;

packaging applications such as pellets and containers; building and construction such as

fencing, lumber replacement, etc. [Ref. 1&3] Melt impregnation using thermoplastic

pultrusion is the dominant manufacturing technique used for continuous fiber-reinforced

thermoplastic materials. However, other alternative manufacturing methods are also

widely used: solution impregnation, powder impregnation, and extrusion impregnation.

The powder impregnation method is the most economical in the manufacture

thermoplastic composites.

Experimental:

In this experiment, commercially available glass and graphite fibers are used to reinforce

thermoplastics such as polyethylene, polypropylene, and ABS. Melt impregnation via

thermoplastic powder impregnation is employed to help manufacture custom made

samples. For the purpose of comparison, a set of control samples using glass, graphite

fibers, and thermosetting polyester resin are also produced. Two types of sample

geometry are used: laminate panels and square rods. Material parameters such as stacking

sequence, reinforcement orientation, and fiber volume fraction will be incorporated in

order to study their influence in the overall mechanical properties. In this case, fiber

orientations used are as 0, 45, and 90 degrees. A stacking sequence 0/45/90 is used

throughout.

Unidirectional glass and graphite fabrics (1.5-mm and 1.7-mm thick, respectively) are cut

to size (203.2 mm x 203.2 mm) and laid in a custom designed aluminum mold (Figure 2).

62
Thermoplasticresinsin apowderfrom,rangingfrom 9to 20gms,areuniformly

dispersedontotheglassor graphitefabrics.A laminatewith twenty-fourlayers[+45/-

45/0/90/-45/+4512s, approximately3-mmthick, wasproduced.Thefiber volumefraction

in thelaminateswasabout55-60%.Thegeneralmanufacturingprocedurefor

thermoplasticcompositesis to heatup thefabricswith theembeddedresinpowders

abovethemeltingtemperatures(125°Cfor PE,175°Cfor PPand240°CforABS), and

thenapplyarelativelyvery low pressure.ForPEandPPmatrices,theultimateoperating

temperatureis higherthantheirmeltingtemperatures,soasto eliminateall spherulite

nucleiandthento re-solidify amoreuniform crystallinestructure.Thelaminateis then

transferredto alaminatingpressthatisheld atatemperatureslightlybelowthemelting

temperature(Figure 1).Thepressureis approximately4 MPa,andis appliedfor 30

minutesto ensuregoodconsolidation.In this consolidationprocessthepressurebrings

thepliesinto intimatecontact,andremovesanyentrappedairbubblesor voids.This

pressureapplicationtime permitsadequateresinflow andensuresstronginterlaminar

adhesion.Any reduction in pressure and/or pressure-application time that doesn't

comprising laminate quality will enhance production cost and production rate. The mold

is finally placed in a cold water bath such that the desired shape is maintained. After

cooling to room temperature the mold is opened, the formed part is removed, and

secondary operations such as a trimming and machining are performed.

Tensile and three-point bending specimens are cut from the laminates: impact bars are

machined from the square rods. A "V" notch is cut into each of the impact specimens.

Tests are performed in accordance with ASTM standards [D790 (bending test), D638

(tensile test), and D-256 (Izod impact test)]. Loading of tensile and bending specimens is

relatively low such that deflection is below a maximum of 10 mrn/min. Fractured samples

are then examined using optical and scanning electron microscopy.

Results:

Test results are shown in Tables 1 and 2. Table 1 presents the mechanical properties for

fiber-reinforced thermoplastic and thermosetting composites, whereas Table 2 contains

properties for the graphite-reinforced materials. As noted in these tables, thermosetting

composites (both glass- and graphite-reinforced) have higher tensile strengths. However,

their impact and flexural strengths are generally lower than their thermoplastic

counterparts. Among the thermoplastic composites, those with the ABS matrix exhibit

the best mechanical properties. The fracture mechanism for impact damage from highspeed loading involves fiber breakage, matrix cracking, and delamination. On the other

hand, a slow loading rate such as is found in tensile and flexural tests produces composite

fracture behavior that is determined by the interracial bonding strength and strain energy

in the composite. Figure 3 and 4 (optical photomicrographs) show that the fracture

process is often initiated from a large crack site; this is followed by crack propagation

through the fiber-matrix interface. Studies using scanning electron microscopy, the

results of which are shown in Figures 5 and 6, indicate that the poor interfacial bonding

develops in the interlaminar area.

Conclusions:

Experimental data suggest no significant difference in unidirectional tensile properties

between thermoplastic and thermoset composites. With different fiber orientations, the

tensile properties for thermosetting composites are superior to thermoplastic ones. This is

63
mainly dueto fiber fractureprocess.In general,thermoplasticcompositesoffer better

impactproperties.Thermosettingcompositesoffer strongtensileandflexural strengths.

Recommendations:

Further research work in the determination of fiber wetting condition and interracial

boding strengths of thermoplastic composites will be desirable. Projects can be extended

to structure design, processing techniques, and environmental considerations

(temperature, solvent, aging process).

References:

1. Bowen, Stephen T. Long Fiber Reinforced Thermoplastics (LFRTP) Market

Overview, SPE Newsletter, Composite Division, Vol. XI, No.2, April 2000.

2. Carlsson, LiefA. (Editor), Thermoplastic Composite Materials, Vol.7, Elsevier

Science Publishing: New York, New York, 1991.

3. Holty, David H., Greene, Tim L., Muzzy, John D., and Parkin, Michael J.

Performance Advantages of Thermoplastic Composite Tubes in Sports Applications,

SME Composites in Manufacturing, Vol. 12, No. 1, First Quarter 1996.

4. Kausch, Hans-henning (editor), Advanced Thermoplastic Composites:

Characterization and Processing, Hanser Publishers: Munich, Germany, 1993.

5. Newaz, Golam M. (editor), Advances in Thermoplastic matrix Composite Materials,

STP 1044, ASTM: Philadelphia, Pensylvania, 1989.

6. Rasato, Dominick V., Designing with Reinforced Composites, Hanser/Gardner

Publications: Cincinnati, Ohio, 1997.

7. Swanson, Stephen R., Introduction to Design and Analysis with Advanced Composite

Materials, Prentice-Hall: Upper Saddle River, New Jersey, 1997.

64
Table 1. Mechanical Properties of Glass Fiber-Reinforced Thermoplastic and

Thermosetting Composites

Types of

Composites

Tensile Stress

OIPa)

Strain to

Failure

(%)

2.7

Notched Izod

Impact Strength

(J/m)

0/90 Glass/PE 63 65

+45/0/90/+45 65 2.8 60 89

Glass/PE

0/90 Glass/PP 95 2.4 93 112

+45/0/90/+45 100 2.2 95 120

Glass/PP

0/90 Glass/ABS 101 2.4 109 125

+45/0/90/_+45 113 2.1 113 129

Glass/ABS

0/90 85 1.1 77 206

Glass/Polyester

+45/0/90/__+45 90 0.9 75 210

Glass/Polyester

Flexural

Strength

(MPa)

86

Table 2. Mechanical Properties of Graphite Fiber-Reinforced Thermoplastic and

Thermosetting Composites

Types of

Composites

Tensile Stress

OIPa)

Strain to

Failure

(%)

Notched Izod

Impact Strength

(J/m)

Flexural

Strength

(MPa)

0/90 Graphite/PE 75 1.7 66 56

+45/0/90/+45 76 1.5 70 69

Graphite/PE

0/90 Graphite/PP 93 1.1 80 88

+45/0/90/+45 97 0.9 82 89

Graphite/PP

0/90 112 1.3 88 119

Graphite/ABS

+45/0/90/+45 118 1.5 85 121

Graphite/ABS

0/90 Graphite 570 0.6 59 335

/polyester

+45/0/90/+45 695 0.4 54 366

Graphite/polyester

65
Figure 1. Lamination Presses in the Composite Laboratory.

Figure 2. AnAluminumMold Is Being Placed between TwoHeated Platens with

Pressure.

66
Figure3. CracksInitiatedatLowerRight Comer;InterlaminarFiberDebonding.

Figure4. FractureCracksPropagatedthrough0 and90-DegreeFiberOrientations

67
Figure 5. Fracture in Thermo _lastic Matrix with Extensive Delamination.

Figure 6. Poor Interfacial Bonding and Fiber Breakage Shown in Thermoplastic

Composites. 68
LIGHTWEIGHT AUTOMOTIVE

MATERIALS D ATABASE

P. K. Mallick

Department of Mechanical Engineering

University of Michigan-Dearborn

Dearborn, Michigan 48128

Telephone 313-593-5119

e-mail pkm@umich.edu

69
P. K. Mallick

70
71
72
73
74
75
76
77
78
79
....... L ....

II

0

81
FRACTURE BEHAVIOR OF NYLON

MONOFILAMENT FISHING LINE

Wayne L. Elban

Loyola College

Department of Electrical Engineering and

Engineering Science

4501 North Charles Street

Baltimore, Maryland 21210

Telephone: 410-617-2853

e-mail welban@loyola.edu

81
Biography:

Since 1985, Professor Elban has

taught engineering science courses at

Loyola College, including introductory

materials science, materials science lab,

mechanical properties of materials, and

transformations in solids. He received a

BChE with distinction ('69) and a PhD

in Applied Sciences: Metallurgy ('77)

from the University of Delaware and a

MS in Engineering Materials ('72) from

the University of Maryland, College

Park. From 1969-1985, he was a

research engineer at the Naval Surface

Warfare Center, White Oak Laboratory,

Silver Spring, Maryland. He is a

member of ASM International.

Wayne L. Elban

82
FRACTURE BEHAVIOR OF NYLON MONOFILAMENT

FISHING LINE

Wayne L. Elban

Dept. of Electrical Engineering and Engineering Science

Loyola College

Baltimore, Maryland 21210

ABSTRACT: A procedure is described for characterizing the fracture behavior of

commercial 6-1b test nylon monofilament fishing line. A bench-top universal testing machine

is used to obtain determinations of tensile fracture load (strength) and displacement

(elongation at break). Emphasis is given to placing specimens in several fixture

configurations to distinguish valid experimental data from that influenced by testing artifacts.

Specimens with a single overhand knot are tested to determine its stress concentrating effect.

As-manufactured fishing line and exterior sample surfaces immediately behind the fracture

surfaces are examined using a reflected light microscope. Experimental determinations of

mechanical properties are compared to values appearing in the literature.

KEY WORDS: Uniaxial tensile testing, reflected light microscopy, mechanical deformation

properties, fracture, stress concentration, manufacturing defects, thermoplastic polymers,

nylon, monofilament fishing line.

PREREQUISITE KNOWLEDGE: sophomore-level undergraduate laboratory experiment

requiring basic knowledge of thermoplastic polymers and their mechanical

deformation/fracture behaviors and of mechanical property testing as described in an

introductory materials science course and accompanying laboratory course.

OBJECTIVES:

(a) Experimental Goals:

.

to measure the uniaxial tensile mechanical properties to fracture of a

commercial thermoplastic polymer;

2. to distinguish valid versus invalid experimental data;

3. to assess the effect of stress concentration in a thermoplastic polymer;

. to identify possible manufacturing defects in a commercial thermoplastic

polymer using reflected light microscopy; and

5. to assess the brittle-ductile character of fracture of a thermoplastic polymer.

83
(b) LearningGoals:

.

to become familiar with uniaxial tensile testing, a prominent technique for

characterizing the mechanical response of materials;

.

to become familiar with the occurrence of testing artifacts and their effect on

experimental data and their interpretation;

,

to become familiar with bulk-deformation processing (extrusion/drawing) and

its effect on the mechanical properties of thermoplastic polymers;

. to become familiar with the effect of stress concentration on material

deformation/fracture behaviors;

.

to become familiar with reflected light microscopy, a prominent technique for

assessing material microstructure, using various types of illumination; and

6. to become familiar with the distinctive features of brittle and ductile fracture.

EQUIPMENT AND MATERIALS: (1) Chatillon model LRX universal testing machine

(bench top model with 500-1b capacity); (2) Wedge-action grips (Chatillon model TG15N);

(3) Bollard wire, yarn, and thread grips (Chatillon model TG12N); (4) Metric universal dial

caliper (Brown and Sharpe 559-579-13); (5) Ruler; (6) Zeiss model ICM 405 bench

metallograph; (7) Extruded nylon monofilament fishing line [South Bend No. M-146 6-1b test

(or equivalent)] (Instructor Note 1); (8) Extruded nylon monofilament fishing line [South

Bend No. M-146 6-1b test (or equivalent)] attached to 1" x 1.5" cardboard tabs using hot

glue gun (Instructor Note 2).

SAFETY PRECAUTIONS: Care must be taken to avoid being burned when using hot

glue gun to attach fishing line to cardboard tabs. (Instructor Note 2)

INTRODUCTION:

Problem Statement: You have recently been hired as a materials engineer by a manufacturer

of nylon (Table 13.1, Ref. [1]) monofilament fishing line. You are asked to investigate

whether customer complaints of 6-1b test nylon monofilament line breaking at loads below

the advertised test force are valid. Your company recently acquired a new universal testing

machine (Chatillon model LRX) equipped with a couple of different types of grips. The

tester is computer controlled and has computer data acquisition capabilities, and your boss

wants you to use it with appropriate grips in your assessment of the maximum force and

corresponding displacement (extension) of the fishing line in question. Further, your boss

suspects that the real explanation for any low-force failures is the presence of knots in the

line that are introduced by the customers or more likely by their children. (Instructor Note 3)

Your boss also asks you to perform a microscopic examination to gain relevant

microstructural information. There is an interest in determining whether surface flaws are

84
present in the as-manufactured fishing line and in assessing the character of the resultant

fracture surfaces and their vicinities.

Nylon is a prominent example of a large class of industrially important materials

known as thermoplastic polymers. Their structure is usually linear, although branching is

possible. Nylon is synthesized by condensation reaction, and typical uses include outdoor

fabrics, carpet fibers, and monofilament fishing lines (introduced by Berkley in 1957 [2]).

Upon heating above room temperature, thermoplastic polymers undergo significant changes

in their elevated temperature mechanical properties as determined, for example, by uniaxial

tensile testing, including decreases in elastic (Young's) modulus and fracture strength and

increase in elongation at break. However, chemical decomposition is minimal.

Taking advantage of the elevated temperature properties of thermoplastic polymers,

filaments are manufactured by a continuous extrusion process [3-5]. The starting materials

are pellets, granules, or powders of polymer already synthesized to the desired molecular

weight. These are delivered into an extruder barrel containing a slightly undersized screw

that blends and transports the starting material along the barrel. Frictional heating results,

that can be supplemented by exterior heaters, causing the polymer to melt. A pressure buildup also occurs as the material progresses down the barrel. The molten polymer then travels

through multiple cylindrical dies located at or beyond the far end of the barrel. The

extrudate is typically water-cooled and collected onto rollers or spools. This material then

passes through a series of rollers to draw or stretch the filaments.

From a materials science viewpoint, the essential characteristic of the drawn filament

is its highly anisotropic structure and properties. The intense shearing action during the

extrusion process causes some segments of the linear polymer molecules to begin aligning

themselves in the flow field, particularly as they travel through a die. The drawing operation

greatly improves the alignment of molecules along the filament longitudinal axis. As a

result, the highest tensile strength is realized in this direction as desired, for example, in

nylon monofilament fishing line. However, transverse strength is significantly lower.

The purpose of this experiment is to investigate the fracture behavior of nylon

monofilament fishing line. To this end, a quantitative evaluation of fracture strength and

elongation at break will be made from uniaxial tensile testing measurements. The usefulness

of several different specimen fixtures will be assessed by noting where specimen failures

occur. Line diameters will be measured before and after testing. Subsequently,

representative resultant fracture surfaces and their immediate vicinities will be examined to

determine their character (i.e., degree of brittle versus ductile fracture) using reflected light

microscopy. As-received line and other regions of tested line will also be examined for

manufacturing defects and evidence of slip and kink band formation, respectively. To verify

determinations of strength and elongation, the experimental values will be compared with

those values for nylon appearing in the literature.

85
PROCEDURE:

A. TENSILE TESTING (Instructor Note 4)

1. Measurements:

a. Measure the diameter of each specimen using a dial caliper prior to tensile testing.

b. Perform tensile testing (specimen gage length = 4 in. or 43⁄4 in. when using

bollard grips; crosshead speed (CHS) = 1 in./min -- Instructor Note 5) on five (5)

specimens minimum for the following sample types:

(i) bare 6-1b test nylon monofilament line using wedge-action grips (Instructor

Note 6);

(ii) 6-1b test nylon monofilament line with cardboard tabs using wedge-action

grips (Instructor Note 6);

(iii) bare 6-1b test nylon monofilament line using bollard grips; and

(iv) bare 6-1b test nylon monofilament line with single overhand knot

(positioned roughly in middle) using bollard grips.

For each specimen, note where failure occurred.

. After testing, place transparent tape around both specimen pieces near gripped ends;

tape keeps specimen pieces together and provides a convenient label for handwritten

identification.

3. Retain all specimen pieces for subsequent dimension measurements and examination.

. Record your measurements and any relevant observations in your laboratory notebook

with one or more drawings as appropriate.

B. DIAMETER MEASUREMENTS OF RECOVERED SPECIMENS

. Using a dial caliper, measure the diameter of each specimen no more than several

millimeters away from the break.

. Record your measurements and any relevant observations in your laboratory notebook

with one or more drawings as appropriate.

C. MICROSCOPIC EXAMINATION OF RECOVERED SPECIMENS

1. Preparatory Reading Assignment:

a. Read Restivo [6], providing information on the operation of reflected light

microscopes and types of illumination.

86
.

.

.

b. Read Vander Voort [7], providing additional information on types of illumination.

Using the Zeiss model ICM 405 bench metallograph with brightfield illumination,

examine a segment of untested (as-manufactured) fishing line for the presence of

surface flaws.

Begin by devising a technique to view the segment along the filament axis. Describe

this technique with appropriate drawing in your laboratory notebook. (Instructor Note

7)

Record any relevant observations of the surface in your laboratory notebook with one

or more drawings as appropriate.

Examine a representative tensile specimen, both with and without a knot, tested with

bollard grips.

Record your observations of the fracture surface and neighboring regions along the

line axis. Pay particular attention to the degree of roughness of the fracture surface

and whether it is nominally perpendicular to the line axis. Since the transverse

strength of the line is expected to be considerably below the longitudinal strength,

axial splitting is also possible. Assess whether brittle or ductile failure [8] appears to

have occurred. Determine whether the line has undergone a significant decrease in

diameter (i.e., necking as shown in Figure 13.18, Ref. [9]) in the vicinity of the

fracture surface. Also, determine whether there is any evidence for slip band or twin

boundary formation (Figure 2.5, Ref. [10]) and look for porosity and microcracks.

For a representative specimen with and without a knot tested with bollard grips,

obtain a low magnification (i.e., 50X) photomicrograph using Polaroid Type 57 film

(3000 ASA/36 DIN) with each of the following illuminations [6,7] (Instructor Note

8):

a. brightfield;

b. darkfield;

c. polarized light; and

d. differential interference contrast (Nomarski).

° Record any benefits and additional microstructural information gained using the latter

three illuminations.

D. ANALYSIS

Perform the following analyses and respond to any questions as completely as possible,

being sure to show all of your work and reasoning as partial credit can be earned.

87
.

.

.

.

.

.

.

Tensile testing measurements -- for each sample type, do the following:

a. Tabulate the measured values of fracture force and displacement at break; and

b. Calculate [11] the average and standard deviation, a, for both sets of values.

Discuss what happens when bare fishing line is tested using wedge-action grips.

Emphasis should be given to the validity of the data and explain what is physically

happening to the specimens.

Discuss what happens when fishing line attached to cardboard tabs is tested using

wedge-action grips. Emphasis should be given to the validity of the data and explain

what is physically happening to the specimens.

Discuss what happens when bare fishing line is tested using bollard grips. Emphasis

should be given to the validity of the data and explain what is physically happening to

the specimens.

Discuss what happens when bare fishing line with a single knot is tested using bollard

grips. Emphasis should be given to the validity of the data and explain what is

physically happening to the specimens.

Conclude which is correct, the complaints of customers or the suspicion of your boss.

Be sure to justify carefully your answer based on the measurements that you obtained.

For the line tested using the bollard grips:

a. Calculate fracture strength (crf) and elongation at break (eb) for each specimen

using engineering stress-strain relationships (e.g., Eqns. (2-1) and (2-2), Ref.

[12]):

af = Ff/(rdo2/4), (1)

where Fe = fracture force in force-displacement curve, lbf, and

do = initial diameter of specimen, in.; and

b.

eb = Alb/lg, (2)

where A1 b = corresponding displacement at fracture (break) in forcedisplacement curve, in., and

lg -- specimen gage length.

Calculate [11] the average and standard deviation, tr, of these determinations

(Instructor Note 9).

88
C. Compare calculated values to literature values for nylon reported in Table

13.3, Ref. [13]. Discuss the reason(s) why agreement is poor if that is the

case.

8. Specimen diameter measurements:

a. Calculate the change in diameter, Ad, in units of mm, for each specimen

using:

Ad =dt- do, (3)

where d t = diameter of recovered specimen tested in tension, mm, and

do = initial diameter of specimen, mm.

b. Calculate [11] the average and standard deviation, tr, of this determination for

each sample type.

. Discuss the effect that tensile testing has on the dimensional stability of the

specimens.

10. Discuss the evidence for as-manufactured surface flaws in the fishing line.

11. Discuss the character of the fracture surface for specimens with and without knots.

12. Discuss any microstructural features observed along the fishing line away from the

fracture surfaces.

13. Discuss the benefits of using darkfield, polarized light, and differential interference

contrast (Nomarski) illuminations.

COMMENTS with Data Sheets and Plots:

All of the experimental steps were performed a number of times to verify that the results are

reproducible. The data sets appearing in this section are considered to be representative for

the South Bend line. A complete set of measurements obtained for 6-1b test line from a

different vendor (Berkley) appears in the Appendix. (Instructor Note 1)

Effect of Specimen Fixture on Uniaxial Tensile Testing Response: Force and displacement

measurements taken from experimental curves (e.g., Figure 1) are given in Table I for the

South Bend fishing line placed in various fixtures. The average breaking force of the bare

line tested in the wedge-action grips is 3.00 lbf (13.3 N), which is 50.0% of the line's

advertised lb-test rating. However, the results obtained with this fixture are invalid because

fracture occurred at one of the grips rather than in the specimen middle as desired. The

fracture location indicates that the grip has a stress concentrating effect on the line causing

premature failure at an artificially low force.

89
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monofilament fishing line (specimen SB1400) tested with bollard grips

in uniaxial tension.

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The average breaking force of line with cardboard tabs tested with wedge-action grips

improved to 4.22 lbf (18.7 N), corresponding to 70.3 % of the line's rating. These results

are also invalid because failure now occurs by filament pull-out, which is analogous to the

interfacial failure that is sometimes observed in continuous fiber/polymer matrix composites

[14]. The filament end is devoid of adhesive (hot glue), indicating that the filament/adhesive

interfacial bond broke. Failure by filament pull-out results in a series of pronounced load

drops in the tensile response (Figure 2). Maximum force (reported in this case, rather than

fracture force which did not occur) is achieved immediately prior to commencement of pullout. Successive extension is accompanied by additional pull-out events, each occurring at a

force lower than that necessary for the initial event since the bonded area is decreasing.

Bare line tested in bollard grips yielded an average breaking force of 5.49 lbf (24.4

N). Although this is the highest value obtained using the three specimen fixtures, it is still

only 91.5 % of the line's rating. The force-displacement curve (Figure 1) exhibits what

appears to be a yield point a little prior to breaking that is believed associated with the

observations of kinking in recovered specimens. Four of the six specimens broke in the

middle, while fracture in the remaining two occurred near (but not at) a bollard. As such,

the bollard that takes up the filament before it is clamped in each grip successfully isolates

the specimen from the deleterious effect of clamping. Thus, all of these measurements are

valid, and assertions by customers are credible.

Effect of Specimen Knot on Uniaxial Tensile Testing Response: Bare line with a single

overhand knot tested in bollard grips yielded an average breaking force of 3.71 lbf (16.5 N).

This corresponds to attaining 67.6% of the breaking force for the same line without a knot

and compares favorably with a number of values obtained [15] from analogous sets of

measurements for different 30- and 50-1b test nylon monofilament lines. The tensile curve

(Figure 3) failed to exhibit the apparent yield point seen in Figure 1, presumably because the

breaking force was below that necessary to cause prominent kinking. As expected, all six

specimens broke at the knot, demonstrating the notch weakening effect that occurs in nylon.

The stress-concentration factor for the knot is relatively modest: estimated [16] to be about

1.3 initially and to decrease to 1.2 as the knot tightened to breaking. The combined results

reveal that the boss' suspicion has a sound technical basis.

Literature Comparison: The resultant fracture strength and corresponding elongation

determinations for bare South Bend fishing line tested in bollard grips appear in Table II.

There is very poor agreement between the experimental strength of the oriented nylon

monofilament fishing line and that appearing in the literature for bulk polymer; an average

value of 78,400 psi (540 MPa) was obtained for the fracture strength versus a value of

11,800 psi (81.4 MPa) reported [13] for the tensile strength of commercial-grade material.

However, there is very good agreement for the ductility parameter; an average value of 56%

was obtained for the elongation at break compared with a reported [13] value of 60%. The

relatively high fracture strength of the fishing line is attributed to the polymer molecules

becoming aligned during the drawing operation along what is to become the tensile axis. As

such, a relatively high percentage of strong intramolecular bonds oppose the applied force

compared to relatively randomly oriented bulk polymer, where a much higher percentage of

significantly weaker intermolecular bonds participate.

93
7.500 .......................................................................................

Load (ibf)

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Extension(in) 2,500

Figure 2. Force-displacement curve for South Bend six-pound test nylon

monofilament fishing line with cardboard tabs (specimen SB0900) tested

with wedge-action grips in uniaxial tension.

94
7.500 .................. -r-............. -,-................ -,-.................................

Load (ibf)

0.0000

0.0000

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Extension(in) 5,000

Figure 3. Force-displacement curve for South Bend six-pound test nylon

monofilament fishing line with single overhand knot (specimen SB2400)

tested with bollard grips in uniaxial tension.

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Diameter Change Assessment: Diameter measurements obtained before and after testing each

specimen appear in Table III. Changes in diameter are also provided. For a given sample

type, no statistically significant change in diameter was measured, indicating that necking did

not occur, unless extremely localized in the vicinity of the break.

Microscopic Observations: Fishing line specimens were examined with all four illuminations

to assess their usefulness. Brightfield illumination yielded photographs with a great deal of

undesirable scattered light, while darkfield illumination was impractical because so little light

reached the objective lens making for extremely long exposure times. Both polarized light

and differential interference contrast (Nomarski) provided excellent results, and several

photomicrographs are referred to in the discussion that follows.

Examination of as-received line revealed (Figure 4) numerous small surface pits and

several longitudinal scratches. The most prominent defects were a series of nearly equally

spaced, shallow circumferential grooves that resemble small necked regions and probably

formed during the drawing operation. Other portions of the line segment had frequent

surface pits without additional grooves, indicating that the grooves are not present

throughout. Nonetheless, these observations additionally support customer claims that the

fishing line does not perform as rated since the defects would serve to initiate fractures

resulting in reduced breaking forces.

The fracture surface (and immediate vicinity) of line tested with bollard grips revealed

(Figure 5) that brittle tensile failure occurred in the absence of axial splitting. A high degree

of roughness was present as the fracture surface was jagged and appeared to be torn. The

irregular surface is attributed to the fracture path "seeking out" low molecular weight, low

crystallinity regions that are interspersed unevenly among regions of high molecular weight

and high crystallinity. [17] The low molecular weight, low crystallinity regions serve as

"Griffith-like" flaws; brittle fracture results when the material experiences high enough stress

to cause these flaws to grow. There was no apparent necking, but a short kinked region may

be present. A separate kinked region about 1⁄4 in. from the break had (Figure 6) two bright

transverse bands near the center of the bent region and numerous fine transverse lines that

may be more closely spaced in the bent region, all of which are attributed to slip and kink

band formation [18].

The knotted region behind the fracture surface exhibited (Figure 7) significant

ductility manifested as pronounced flattening of the line resulting from transverse

(compressive) loading as the knot tightened during tensile testing. Examining the other

fracture surface of this specimen revealed that brittle fracture also occurred, although

compared to Figure 5, the degree of surface roughness was significantly less. Axial splitting

did not occur for the knotted specimen either.

INSTRUCTOR NOTES:

1. This particular nylon monofilament fishing line is estimated to be about ten years old and

has undergone degradation in mechanical properties that is typical of nylon line this old, such

that the 6-1b test rating is no longer achieved. This line was chosen because this unexpected

97
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Figure 4. Photomicrograph (differential interference contrast: Nomarski)

of exterior surface of as-manufactured South Bend six-pound test nylon

monofilament fishing line.

100
Figure 5. Photomicrograph (polarized light) of near-fracture surface region

of South Bend six-pound test nylon monofilament fishing line tested with

bollard grips (specimen SB1400).

101
Figure 6. Photomicrograph (polarized light) of kinked region - _,_ in.

from fracture surface of South Bend six-pound test nylon monofilament

fishing line tested with bollard grips (specimen SB1400).

102
200/lm

Figure 7. Photomicrograph (polarized light) of fracture surface region

of South Bend six-pound test nylon monofilament fishing line with

knot tested with bollard grips (specimen SB2400).

103
(for the student) complication allows the student to exercise critical thinking skills beyond

having to sort out which specimen fixtures give invalid test data. A second set of test

data/results for more recently manufactured line from a different vendor (Berkley) is included

in the Appendix. This material still yields (actually exceeds) the stated (6-1b) test rating.

2. This specimen fixture must be created before actual testing. The procedure is done the

day before to allow the glue to set up completely. Students can be given this task depending

on their schedules. Preparatory to assembling specimens, 1" x 1.5" cardboard tabs are made

using a paper cutter. The cardboard backing on paper pads provides excellent starting

material. If students are involved, they should be shown how to operate a hot glue gun and

to position line specimens onto tabs while being glued. See SAFETY PRECAUTIONS.

Line is centered along the long dimension of one tab, and hot glue is applied directly to the

line/tab. The second tab is quickly laid on top and firmly pressed down for about a minute

until the glue gels. The procedure is repeated to create a second "sandwich" (line between

two tabs). Once cool, excess line and glue can be easily trimmed with scissors.

3. This part of the experiment relates to a previous year's National Educators' Workshop

paper [19] providing a very nice description for evaluating the load reducing (stress

concentrating) effect of knots in various lines and threads.

4. Students should be shown how to operate the universal testing machine and to position

specimens in the machine prior to actual testing. Consideration should be given to having

students develop a written standard operating procedure (SOP) during the week before actual

testing. This activity provides valuable practice because an SOP is often required before

approval is given to operate equipment in laboratory or manufacturing venues.

5. It recently has come [20] to the author's attention that while a standard test procedure

apparently has not been formally established, nylon monofilament fishing line is typically

tested wet (after soaking in tap water for two hours) using a gage length = 12 in. and a CHS

= 10 in./min. Five specimens are evaluated for each test sequence. Nylon is water

conditioned because its mechanical properties decrease [21] when exposed to water, and

hence the attempt to simulate service life conditions. While water degrades mechanical

properties, the slower CHS used in the current experiment should result in a lower strength

because of nylon's strain rate sensitivity.

6. The first two specimen fixtures provide invalid experimental data but are included to allow

students the opportunity to distinguish valid versus invalid test data, all obtained by computer

and reported to four significant figures. The faces of wedge-action grips have a relatively

sharp sawtooth profile that "bites" into the specimen to inhibit slippage during testing.

However, the bare, small diameter line is significantly pinched by the grips creating a stress

concentration, and the notch sensitive character of nylon is manifested by the fracture

occurring at one of the grips with consequent artificially low fracture load. Tabs are

attached with glue to isolate line from the grip faces during testing. While the approach

accomplishes this objective, invalid data also results because the glue does not adhere to the

line sufficiently well. An artificially low load is obtained since the filament pulls out of one

of the tabs during testing before fracture can occur.

104
7. Fishing line can be readily viewed by taping it to the microscope stage in one or two

places to keep it from moving while the stage is being manipulated. Transparent tape is

suggested because adhesive residue is not left upon removal from the specimen or stage.

8. Long exposure times (on the order of 30 s) are required to obtain photomicrographs with

illuminations other than brightfield. Spurious light entering the inverted objective lens can be

avoided by turning off the overhead lights while the camera shutter is open.

9. The uncertainty in the elongation determinations is large because displacement was

obtained indirectly from constant CHS rather than using the preferred technique of affixing

an extensometer to the specimen, thus providing a direct measurement. Fortunately, the

fracture strength of fishing line is of much greater interest than its strain capacity. However,

an appropriate laser extensometer is available from Ametek (Chatillon) for small diameter

fishing line specimens undergoing large extensions; in addition, an IR light extensometer

suitable for such measurements is currently under development. [22]

REFERENCES:

[1] Flinn, R.A.; and Trojan, P.K.: Engineering Materials and Their Applications, 4th

Edn., Houghton Mifflin Co. (now John Wiley and Sons, Inc.), 1990, p. 548.

[2] Evans, S. (Ed.): "Trout Fishing History and Lore," in Sports Afield Trout Fisher's

Almanac: Expert Advice from America's Greatest Anglers, The Atlantic Monthly

Press, 1997, pp. 1-29.

[3] Kalpakjian, S.: Manufacturing Processes for Engineering Materials, Addison-Wesley

Publishing Co., 1991, pp. 650-652.

[4] Strong, A.B.: Plastics: Materials and Processing, 2nd Edn., Prentice-Hall, Inc., 2000,

pp. 351-390 and 400-403.

[5] Dugger, A.: "Line Lotto: Different Lines for Different Needs," Sport Fishing,

Volume 7, February 1992, pp. 70-77.

[6] Restivo, F.: "A Simplified Approach to the Use of Reflected Light Microscopes,"

Form No. 200-853 (1987), Leco Corporation, 3000 Lakeview Avenue, St. Joseph,

Michigan, 49085.

[7] Vander Voort, G.: "The World Beyond Brightfield Illumination," Tech-Notes: Using

Microstructural Analysis to Solve Practical Problems, Volume 1, Issue 3 (1997),

Buehler Ltd., 41 Waukegan Road, Lake Bluff, Illinois 60014.

[8] Hertzberg, R.W.: Deformation and Fracture Mechanics of Engineering Materials, 4th

Edn., John Wiley and Sons, Inc., 1996, pp. 298-303.

[9] Flinn, R.A.; and Trojan, P.K.: op. cit., p. 586.

105
[10] Flinn, R.A.; and Trojan, P.K.: _, p. 93.

[11] Holman, J.P.: Experimental Methods for Engineers, 6th Edn., McGraw-Hill Book

Co., 1994, p. 58.

[12] Flinn, R.A.; and Trojan, P.K.: _, p. 88.

[13] Flinn, R.A.; and Trojan, P.K.: _, pp. 560-561.

[14] Flinn, R.A.; and Trojan, P.K." _, pp. 661-663.

[15] Dugger, A.: "Break Point: We Test 50- and 30-Pound Lines," Sport Fishing, Volume

12, April 1997, pp. 48-54.

[16] Hertzberg, R.W.: op. cit., p. 276.

[17] Warner, S.B.: Fiber Science, Prentice-Hall, Inc., 1995, pp. 53-59.

[18] Zaukelies, D.A.: "Observation of Slip in Nylon 66 and 610 and Its Interpretation in

Terms of a New Model," Journal of Applied Physics, Volume 33, September 1962,

pp. 2797-2803.

[19] Karplus, A.K.: Knotty Knots, in National Educators' Workshop: Update 93, NASA

Conference Publication 3259, 1994, pp. 369-372.

[20] Blodgett, D.: Telephone Conversation, International Game Fishing Association, Dania

Beach, Florida 33004, May 17, 2000.

[21] Kalpakjian, S.: op. cit., p. 646.

[22] Critoph, A.: Telephone Conversation, Ametek, Largo, Florida 33773, November 9,

2000.

SOURCES OF SUPPLIES: Commercial-grade nylon monofilament fishing line is

inexpensive and readily available at numerous retail stores from a variety of vendors. It is

also possible that some fishing line manufacturers will supply complimentary small spools of

test material and accompanying information. One such example is Pure Fishing Angler

Service, 1900 18th Street, Spirit Lake, Iowa 51360, which sent upon request a student kit

that contained the following: (1) 110-yd Berkley Trilene 10-1b test XL (extra flexible, smooth

casting) line; (2) 110-yd Berkley Trilene 10-1b test XT (extra tough, abrasion resistant) line;

(3) 100-page booklet entitled "Berkley: Catch More Fish"; (4) knot card; and (5) 7-page

research paper entitled "Nylon Monofilament Fishing Lines"

ACKNOWLEDGEMENTS: Special thanks to Mark A. Elban for analyzing all of the

experimental data leading to preparation of Tables I to III and A-I to A-III. Helpful

discussion regarding the fracture behavior of nylon monofilament fishing line was provided

106
by Dr. Ronald W. Armstrong, Professor Emeritus, Department of Mechanical Engineering,

University of Maryland, College Park, who not only has imparted to the author his

wonderful enthusiasm for materials research but also his immense love for fishing, especially

with dry flies. The identification of any manufacturer and/or product in this report does not

imply endorsement or criticism by the author or Loyola College.

APPENDIX: A complete set of test data/results for Berkley Trilene 6-1b test XL line appears

in Tables A-I to A-Ill that follow. (Instructor Note 1)

107
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112
EARTHQUAKES, MATERIALS AND AN

EDIBLE VILLAGE:

AN EDUCATIONAL EXPERIMENT FOR

HIGH SCHOOL STUDENTS

Neda Fabris

Mechanical Engineering Department

California State University, Los Angeles

5151 State University

Los Angeles, California 90032

Telephone 323-343-5218

e-mail nfabris @exchange.calstatela.edu

113
Biographical Information:

Neda Fabris has taught at Cal. State LA since 1979. She teaches classes in

manufacturing, materials, mechanics and design. She holds a Master of Engineering

degree from the University of Sarajevo, Bosnia, and a M. S. and Ph.D. from Illinois

Institute of Technology Chicago Ill, and was a postgraduate researcher at Technishe

Hoch Schule in Aachen, Germany. Her recent awards include the Society of

Manufacturing Engineers "Distinguished Manufacturing Educator" award of Region 12

(Southwest U.S.) in 1998 and the "First Ca1 State LA Distinguished Women

Achievement Award" in 1999. She has contributed several times to this conference.

114
Earthquakes, Materials and an Edible Village:

An Educational Experiment for High School Students

Neda Fabris

California State University Los Angeles

Los Angeles CA 90032

Abstract: This paper describes hands on experiments that demonstrate the influence of

soil, construction material and a structure's shape and size on the performance of a

building during earthquakes. Participmats in the experiment build structures from

toothpicks, marshmallows, breadsticks and gummy balls and place them on the two

containers with different types of "soil". "Soil" is made from clay to represent bedrock

and from gelatin to represent landfill. The containers are then shaken manually,

simulating an earthquake, while participants observe the behavior of different structures.

The experiments are fun, as well as educational, and are suitable for outreach activities

and demonstrations of structural design principles in the "Introduction to Engineering"

class.

Key Words: Natural Frequency, Stiffness, Mass, Resonance

Prerequisite Knowledge: A basic knowledge of algebra and physics as well as a

curiosity to understand what causes some structures to withstand earthquakes better than

others do.

Objectives: The objective of this experiment is to introduce the participants to structural

and materials engineering by demonstrating important concepts in materials, vibrations

and dynamics of structures using structures that they build from every day objects.

Equipment and Materials: No spec!al equipment is necessary. The amount of material

used is dependent upon how many groups of participants there are. The list of material

below is based on one group and has to be multiplied by the number of groups.

We like to team four-five people in one group.

1. 2 pounds of firm artist clay

2. 2 large packages gelatin dessert

3. 2 package unflavored gelatin

4. Boiling water

5. Box of toothpicks

6. 1 pound marshmallows

7. 1 pound of Jelly Drops ("Spice Drops") or gummy balls

8. 1 pound of breadsticks

9. 9"x 6" container

115
Safety Precautions: The only possible problem with this experiment is the mess created

by spilling gelatin during the preparation period, as well as a temptation to eat, throw and

play with "structural elements."

Introduction

This experiment was developed for the "All Geared Up" Girl Scout Engineering Program

in February 2000. It was also performed several times by the participants of the "MotherDaughter" Academy at California State University, Los Angeles during spring and

summer 2000. The experiment was very well received, due to its interactive components

and simple but insightful explanation of the common phenomena in Los Angeles:

earthquakes. Participants worked in teams, used their own creativity and had fun while

learning several engineering and scientific concepts.

Theoretical Background

Earthquake waves propagate through the ground with a frequency between 0-20 HZ. The

structure that has a first natural frequency in that range will be prone to resonance,

causing extensive damage. To avoid resonance, high amplitude shaking and potential

damage, the goal of engineers is to design and build structures with a natural frequency

that is higher than the range of an earthquake frequency.

First natural frequencyfof the undamped single degree-of-freedom system of mass m

and stiffness k can be expressed asX:

Where: k is the stiffness in lb./in, or N/m.

m is the mass in lb. mass or kg

Natural frequencies of the undamped, lumped parameter system with more then one

degree of freedom is given by a similar equation

Where C is the function of number of degrees and ratio of mass and stiffness of each

degree of freedom in the system. For example, for the three degree-of-freedom system,

consisting of three equal masses m and three equal springs k: C=0.445 for the first, 1.25

for the second and 1.80 for the third natural frequency 2.

Although structures are continuous systems with some damping properties, this

simplified model is often used in engineering studies and works very well for introducing

116
participants to the most important factors in structural and seismic design, which can be

summarized as:

A structure with a small mass (weight) and a high stiffness has a high natural frequency.

If that frequency is above an earthquake frequency the building will not resonate during

earthquakes and it will not sustain substantial damage.

High stiffness in a structure is achieved by using building materials with higher modulus

of elasticity (like steel or reinforced concrete) or material with low weight like wood.

Heavy materials (stone, brick and concrete blocks) which are connected to material with

low stiffness, is forbidden for structural use in earthquake prone areas.

Naturally, stiffness of the support (type of ground and anchoring of the structure) as well

as the shape, size and design of a structure, play an important role in the actual stiffness

of the structure.

Experimental Demonstrations

In order to demonstrate concepts discussed above, we prepared in advance the "soil" for

the experiments: a" bedrock" plate made from clay in the container and "landfill" soil

made from gelatin. Gelatin dessert and unflavored gelatin were mixed together and

prepared according to directions for the gelatin dessert to make thicker gelatin that is less

prone to softening during the experiment. Using double amounts of gelatin desserts but

using 50% less water can produce a similar effect. The mixture is poured into a 9x6

Plexiglas baking pan and cooled overnight. For this experiment gelatin must be at least 1

in. deep.

We provided participants with both trays and with boxes of toothpicks, marshmallows,

jelly drops and bread sticks. Participants also received instructions as reproduced below.

Participants had fun making one-story, two- and three- story building of different shapes,

sizes and from different material, as seen from the pictures below. We placed the

buildings on the clay and gelatin "soil" and then shook the containers, simulating

earthquakes, while we observed the damage that the buildings sustained.

In this experiment, participants have learned fast that:

• Buildings made with marshmallows sustain less shaking then those made with

gummy drops (difference in stiffness)

• A one-story building is more resistant to shaking than a three-story building

• Pyramids shapes provide for the stiffest structures

• Buildings on a clay support can sustain more shaking than buildings on gelatin

• You can increase the stiffness of a building by bracing it with diagonal sticks

117
Work SheetGivenTo Students

The following instructions were given to participants.

A. Earthquake Performance of Structures

Goal: The goal of the workshop is to demonstrate the influence of the type of soil (earth),

as well as buildings' size, shape and materials on the stability and endurance of

structures during earthquakes.

In Southern California we have all experienced earthquakes. We have also witnessed that

some buildings and structures fall apart, while others remain intact. Why does this

happen?

In this workshop we will investigate three important factors that influence the behavior

and endurance of structures:

. Type of soil on which buildings are located:

To demonstrate the effect of the ground on the integrity of structures, we will make a

"three-story building" from toothpicks and marshmallows, connecting toothpicks with

marshmallows in each corner. We will erect and shake this "building":

a) on clay (which represents bedrock)

b) on the tray with gelatin (which represents, landfill)

What did you observe? Which building will survive better? What cities were

damaged the most during the 1994 Northridge earthquake? Did the cities built in the

valleys (landfills), like Northridge, or the cities built on the hills (bedrock), likes

Beverly Hills, sustain the most damage?

. Size of the building

Using toothpicks and marshmallows, make four buildings: one single-story, one twostory, one-three stories and one four-story high. Put all of the buildings "landfill"

(tray with gelatin) and shake.

118
What did you observe? Which building survives best, and why? The more stories a

building has, the more the shaking is amplified. Where would you feel an earthquake

more, in a ranch house or in a skyscraper?

. Shape of the building

Using toothpicks and "edible" construction elements (breadsticks, marshmallows, and

gelatin candies), construct buildings of different sizes and shapes (cube, pyramid and

others, be creative).

Which shape survived the "earthquake" best? Can you guess why pyramids are

several thousands of years old? _

. Influence of the material used in building the structure

Makes a one-story "building" from breadsticks and marshmallows and an other with

breadsticks and jelly candies (roughly the same size and shape).

Which one of your materials, a marshmallows or jelly candy, is stronger and stiffer?

Which one survived the earthquake better?

Note: The earth shakes at the relatively low frequency of 0-20 HZ (cycles per

second). A building should be designed to have a higher natural frequency (the

frequency when it vibrates with largest amplitude) than the frequency of the ground

so that it does not resonate with the ground (resonance amplifies the vibration). The

natural frequency of a one-story building is proportional to the square root of the

stiffness divided by its mass. That means: buildings with low stiffness and large mass

do not withstand earthquakes very well (like those made from heavy stones or bricks

with not so stiff cement connections), while the buildings made from strong and stiff

material, like steel or light wood, survive earthquakes very well.

B. Design of an Earthquake Resistant Edible "Village"

When you have learned and understood all of the above, make a village from "edible"

building elements (i.e. breadsticks, marshmallows, jelly beans) that will, in your opinion,

survive the earthquake the best. Your village should consist of five buildings, no two

exactly the same. We will test each village for earthquake survival on the gelatin tray.

Let's see who's village will be the best.t The best group of designers will be recognized as

the most promising civil engineers. Good luck. t

After the buildings were finished, we helped students place the structure on gelatin and

clay bases and then shook the containers to simulate earthquakes.

119
Discussion and Conclusions

In addition to being fun this experiment was an educational experience for participants,

and it demonstrated to the students several important physical concepts. The idea for this

workshop came from my daughter's science textbook, which she used to teach high

school science. 3 In the textbook, the experiments were conducted with only identical

types of "buildings": three-story buildings made from toothpicks and marshmallows and

placed on two different types of ground. I have expanded the concept, using different

building materials and shapes and added the explanation of the underlining theory in

simplified terms. My high school student assistant was instrumental in suggesting

material for the buildings (Gummy Drops, breadsticks).

For the Girl Scouts Engineering Day, we expected 200 participants. My volunteer

assistants, mostly engineering students and members of the Society of Women Engineers,

and I made 15 trays of gelatin, making a big mess in our homes. Actually, we did not

need so many trays, since we had only approximately100 participants, so we used the

same tray for several groups of students.

The workshop was very well received by students, girl scouts chaperones and helpers,

who were quite intrigued to see how earthquake' damage can be simply demonstrated and

explained.

We conducted this experiment during different sessions of, my "Mother-Daughter"

workshops, where the reception was also very good. The experiment was also featured in

the local newspapers. This time we made only four trays of gelatin.

References:

1. Steidel R.F. Jr, An Introduction to Mechanical Vibrations, (3rd ed.), J Wiley & Sons,

New York, 1989

2. Harris C.M. and Crede E.C. (Editors), Shock and Vibration Handbook (2nd ed.),

McGraw-Hill, New York, 1975

3. Aldridge B. and al. Science Interactions (Course 1), Macmillan/McGraw-Hill, New

York, 1993

Acknowledgment:

I would like to thank my daughter, Nicole Fabris, who is a student in the New York

Medical College, for introducing me to this experiment and helping with its execution.

Also my thanks goes to Lisa Grosskopf-Boutwell and Linzi Boutwell for constructive

suggestions and organization of a Girl Scouts Engineering Day. I am especially thankful

to NSF, Division of Human Resource Development, for sponsorship of the "MotherDaughter Academy".

120
DATA REPORTING AND ANALYSIS IN

SCIENCE AND ENGINEERIING COURSES

John P. Elwood

and

Shingara S. Sandhu

Clafin University

400 Magnolia Street

Orangeburg, South Carolina 29115

Telephone: 803-535-5242

121
122
Data Reporting and Analysis in Science and Engineering Courses

Dr. John P. Elwood

Department of Chemistry

Claflin University

Orangeburg, SC 29115

USA

Dr. Shingara S. Sandhu

Department of Chemistry

Claflin University

Orangeburg, SC 29115

USA

Abstract:

. This workshop explores and demonstrates techniques for fully incorporating

professional data reporting and ahalysis into upper level science and engineering courses. The

ifiethods use basic spreadsheet and graphics s6ftware packages.

abo A terrible disparity is often found between what science and engineering students learn

ut computers add what they use them for. The authors have found this opinion to be common

to a large humber of other faculty members. Data storage, analysis, and presentation are essential

to the success of a research scientist. These tasks can all be performed frith one software

package, the modem-day spreadsheet. The use of the spreadsheet for these tasks also reinforces

such non-computer concepts as dependent variable, independent variable, statistics, parameter,

regression analysis, graphs, outliers, etc.

• Tla.e authors, from many years of practical experience, lmve also found it useful to .

separate data up into such categories as physical constants, corthguration data, environmental

data, and run data. Of course, the workshop will also discuss, in a very applied fashion, such

other concepts as spreadsheet functions, derived data, unit specification, essential components of

graphs, etc.

Many advanced instruments today do come with these capabilities built in. However, it is

not clear that the student appreciates the value of such features or would be able to develop such

systems for an itr--house experimental setup. lhese techniques and principles are now being

used quite successfully in the authors' Physical Chemistry and Anal_ftical Physical Chemistry

courses.

Key Words: Data storage, Data Analysis, Dependent Variable, Independent Variable, Statistics,

Parameter, Regression Analysis, Graphs, Oufliers, Spreadsheet Functions, Derived Data, Unit

Specification

Prerequisite Knowledge: Basic knowledge of computer spreadsheets and functions. That is,

entry of labels, numbers, formulas, functions, etc. Prior experience performing scientific

experiments and preparing laboratory reports.

123
Objective: To understand the method of analyzing and presenting experimental data using

standard computer soRware packages.

Equipment and Materials:

°

2.

3.

4.

5.

DOS or Windows base computer

DOS 6.0 or higher or Windows 95 or higher operating system

Lotus 3.0 or higher or Excel 97 or higher spreadsheet package

Graphics capable printer

Apparatus for experiment being recorded and analyzed

Safety Precautions:

As required for experiment being recorded and analyzed

Introduction:

The need for instruction in the use of spreadsheets for data storage, analysis, and

presentation became apparent to the authors from two different facets of their work in an

academic setting- research and teaching.

The need to prepare data for technical presentations is obvious to research scientists. In

reporting work done at Claflin on the high temperature combustion of halogenated hydrocarbons,

the authors developed spreadsheets that served the multiple purposes of storing data, performing

statistical analysis, and yielding presentation data tables and presentation graphics. Samples of

these are included in references 1 and 2.

It also became apparent that a template could be prepared on which to store and analyze

data for different runs. The analysis and graphical presentation was almost identical for all runs.

In fact, much identifying data, such as sample formula, background gas, and date, could be

automatically inserted into titles, legends, and other text.

The above considerations indicate a need for Run Data (partial pressures and absorbance)

and Environmental Data (temperature, sample name, background gas, and atmospheric pressure).

However, the apparatus used included a state-of-the-art, gas phase FTIR spectrophotometer.

This unit not only had temperature control, but also two different sample cells - one with a 10

cm optical path length and one with a 10 m optical path length. These two cells had not only

different optical path lengths but also different volumes. The volume of gas sample per se does

not enter into the calculations (essentially the Beer-Lambert Law) but does create significantly

different manifolding (tubing and valve) requirements. Thus the need for Configuration Data

(optical path length, tubing length, tubing diameter) appeared.

124
The wide range of sample gas partial pressures (concentration) used created small

inaccuracies in final concentrations due to changes in the levels of mercury in the arms of the

manometers. (Pressure measurements were made with simple mercury manometers - one closed=

ended for low sample concentrations and one open=ended for total pressure near atmospheric.)

Formulas were entered into the spreadsheet to make first=order corrections for these changes

assuming the Ideal Gas Law. Hence a data section was created to hold Physical Constants (gas

constant).

At the same time that the authors were conducting the research described above, they

were teaching in the rapidly expanding Department of Chemistry at Claflin University. More

students of ever increasing capabilities and aspirations were enrolling in the sciences at Claflin.

(A major stimulus in recruitment resulted from grants received by Dr. Sandhu, in some cases

with Dr. Elwood, for pre=eollege programs.) It was noted, however, that as today's students

absorb the ever-increasing number of scientific principles, theories, and concepts, they may lose

track of some of the seemingly obvious questions:

What is a large number?

What is a small number?

Are a series of points in a straight line?

It almost seems as if the evolution from slide rule to calculator to computer has taken away the

need for efficiency and dexterity in the use of numbers. For example, a student might enter the

temperature in Celsius in one column, then calculate the temperature in Kelvin by hand and enter

this in another column

Thus it was decided to as much as possible utilize spreadsheets and derived graphics in

laboratory sessions of advanced chemistry courses. These would be similar to the spreadsheets

and graphs utilized in the research mentioned above.

Experimental:

Figure 1 shows an early version of the gas phase FTIR apparatus. The much more

complex manifolding system developed later is shown in Figure 2. Figure 3 is a spreadsheet

developed for this research. It varies slightly from the description under Introduction above in

that Environmental Data is labeled BASELINE DATA and there is no section for Physical

Constants. Figure 4 is the graph generated by the spreadsheet in Figure 3.

Figure 5 shows a spreadsheet that adheres rigidly to the standards set up for coursework.

It goes with an experiment on the use of the Gas Chromatograph. Figure 6 is the graph which is

generated by the spreadsheet in Figure 5.

The following specifics should be pointed out:

.

2.

Wherever possible, data is calculated by spreadsheet formulas (e.g.

temperature in K and Concentration in % by Volume).

Units are always shown, and in separate cells from the data.

125
.

4.

5.

6.

7.

Powers of 10 are included with units when necessary to make cell entries

reasonable numbers.

Titles of spreadsheet and graph include entered data by way of

concatenated text.

A spreadsheet regression function is used to estimate the Extinction

Coefficient, the essential output of the experiment.

Best-fit straight lines are shown on the graph.

A value for R2 or other statistical test of fit is usually given.

Results:

Fig. 6 shows that the peak area is directly proportional to Concentration as a % by

volume. This relationship is linear. Furthermore the best straight fit line appears to go through

the origin. Both peaks show the same linear relationship to concentration but with different

extinction coefficients.

Conclusions:

1.

2.

3.

The spreadsheet serves the multiple purposes of storing, analyzing, and

presenting experimental data.

The graph generated provides a clear illustration of the relationship

between peak area and concentration.

The spreadsheet and graph give a view of the "quality" (accuracy and

precision) of the experiment so the student can determine whether or not it

needs to be repeated and what improvements might be made.

References:

.

.

,

Shingara S. Sandhu, John P. Elwood and Jenee' Robinson, "Mechanism for In Situ

Measurement of Laser Ablated Polymer Transient Species," 215 thACS National

Meeting, American Chemical Society, March 30, 1998.

Shingara Sandhu, John Elwood, Terry Green, LaKeana Jones and Melviena Miller,

"FTIR Analysis of Gaseous Products from Hazardous Waste Combustion," Northeast

Hazardous Substances Research Center, Cambridge, Massachusetts, November, 1995.

Excel 8.0 with Curriculum Integration, Teacher Universe, Inc., Raleigh, NC, 1999.

Biographical Information:

Dr. John Elwood obtained his B.A. degree in chemistry from Northwestern University,

Evanston, Illinois, in 1966. He completed a Ph.D. degree in physical chemistry at Massachusetts

Institute of Technology in 1971. His major research interests rest on intermediary products of the

combustion of halogenated hydrocarbons. He is a

member of the American Chemical Society. He is currently an associate professor and Chair of

126
the Department of Chemistry at Claflin University, Orangeburg, SC, USA.

Dr. Shingara Sandhu obtained his B,S. and M.S. degrees in chemistry from Punjab

University, India. He completed a Ph.D. degree in environmental chemistry at Utah State

University. His major research interests rest on analytical techniques for determination of heavy

metals in environmentally important substmtes and the movement of metals in soils. He is a

member of the American Chemical Society. He is currently a full professor and Director of

Grants and Research at Claflin University, Orangeburg, SC, USA.

Dr. Sandhu has received numerous professional awards from around the world. He was

selected as the South Carolina Governor's Professor of the Year in 1996. Dr. Sandhu has

authored over 50 publications in both domestic and international journals and has spoken at over

20 scientific conferences.

Acknowledgment:

This work was performed at the Department of Chemistry, Claflin University, with

partial support from the U.S Environmental Protection Agency and from the U.S. Department of

Energy.

127
Figure 1. Gas Phase FTIR Apparatus

128
Date of Report

Time of Report

Quantitative Analysis of CH4

In Nitrogen Background at 24.0 C

10/13/95 FILE: 090895AA

15:25

BASELINE DATA CONFIGURATION DATA

Date Run: 9/8/95 Cell: Length:

FTIR cell: ambient Vacu.Man:Diameter:

Sample: CH4 Atmo.Man:Diameter:

Background: Nitrogen Rubb Tbg:Diameter:

Atmo.Mano.: 835 SS Tubng:Diameter:

Vacu.Mano.: i01.i Volumes: Vac. side

Temp (C/K): 24 297.1 Cell:

Atmo.Press: 754.9

i0.00 Diameter 4.45

0.39 Area: 0.12

0.50 Area: 0.20

0.64 Area: 0.32

0.18 Area: 0.02

91.82 Gas side 32.98

155.53 Total: 280.33

RUN DATA

Upper Wavelength

! Lower Wavelength

Run Resid'l Fill Sample mol/L

No. mmHg mmHg mmHg X E -3

Area 1 Area 2

3200 1600

2600 1200

Experi- Esti- Experi- Estimental mated mental mated

1 5 25 20 1.05

2 5 38 33 1.73

3 5 51 46 2.42

4 5 62 57 3.00

5 5 72 67 3.53

6 5 84 79 4.17

0.00

3.06 3.33 1.98 2.30

4.81 5.51 3.66 3.80

8.84 7.69 5.20 5.31

9.34 9.54 6.64 6.59

11.70 11.23 7.62 7.75

12.70 13.26 9.44 9.16

0.00 0.00

Area 1

Regression Output:

Constant 0

Std Err of Y Est 0.701171

R Squared 0.965791

No. of Observations 6

Degrees of Freedom 5

X Coefficien 3.18

Std Err of C 0.i0

Area 2

Regression Output:

Constant 0

Std Err of Y Est 0.218652

R Squared 0.993502

No. of Observations 6

Degrees of Freedom 5

X Coefficient(s) 2.20

Std Err of Coef. 0.03

Figure 3. Spreadsheet Used in Gas Phase FTIR Research

129
Figure 4. Graph Generated from Gas Phase FTIR Research

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130
Quantitative Analysis of Diesel Fuel

In Iso-octane Solvent at 25 C

Experiment Name:

Date of Report:

Date of Run:

Student Name:

File:

Gas Chromatography - Diesel Fuel Calibration

10118/2000

01/11/1999

John Elwood

LAB_911 .XLS

PHYSICAL CONSTANTS

Gas Constant:

Absolute Temperature:

R 8.315 J K-1 mol-1

273.15 K

CONFIGURATION DATA

Column:

Method:

Detector:.

30 m x 0.53 mm cross-linked polydimethylsiloxane

FID1

Flame ionization

ENVIRONMENTAL DATA

Background:

Temperature:

Temperature:

Iso-octane

25 C

298.15 K

RUN DATA

Sample: Diesel Fuel

Peak 1 Peak 2

Retention Time 3.91 rain 4.46 min

Run

No.

Peak Area (10+6 response-min)

Sample Solvent Concentration

(mL) (mL) (% by volume) Exp 1 Pred 1 Exp 2 Pred 2

1 1 99 1 254.8 277.6 186.1 178.0

2 5 95 5 1475.7 1387.8 939.7 889.9

3 10 90 10 2753.2 2775.5 1744.5 1779.8

4 20 80 20 5541.4 5551.1 3564.4 3559.6

0 0.0 0.0

Integrated Volume % Extinction Coefficient

(10+6 response-min vo1%-1)

Peak 1 Peak 2

277.6 178.0

Figure 5. Spreadsheet for Gas Chromatography Experiment

131
Figure 6. Graph Generated from Gas Chromatography Experiment

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132
A REMOTE EXPERIMENT FOR

CLASSROOM USE

Richard B. Griffin

Mechanical Engineering

Carlos L. Yapura

Aerospace Engineering

and

Dimitris C. Lagoudas

Aerospace Engineering

Texas A&M University

College Station, Texas 77843

Telephone 979-845-9779

e-mail RGriffin @mengr.tamu.edu

133
Biographical Information:

Dr. Richard B. Griff'm has been at Texas A&M in Mechanical Engineering since 1977.

His research area is aqueous corrosion, and he received a NACE Technical Achievement

Award in 1992. For the past six years, he has been a member of the Sophomore TeamFoundation Coalition that developed the core engineering science courses, which have

been adopted at Texas A&M University.

Carlos Yapura is a recent Ph. D. graduate of Aerospace Engineering at Texas A&M

University. Currently, he is the test engineer at the low speed wind tunnel Texas A&M

University.

Dimitris Lagoudas is a faculty member in Aerospace Engineering at Texas A&M

University. He has been Co-Team Leader for the sophomore year program. His research

interests are composite materials, and currently, he is the director of the Smart Materials

Institute at Texas A&M University.

Richard B. Griffin

134
A Remote Experiment for Classroom Use

Richard Griffin,

Mechanical Engineering

Carlos L. Yapura,

Aerospace Engineering

Dimitris C. Lagoudas,

Aerospace Engineering

Texas A&M University

College Station, TX 77843

Abstract:

Students have a variety of learning styles, for many, it is essential in the learning

process to experience the subject matter being discussed in class. However, with large

class sizes (60- 80 students per section) it is not always possible to have students perform

experiments. As a result, a remote-site experiment has been developed for use in the

classroom that uses a testing machine capable of tension, compression, and torsion.

Using the knowledge developed from discussions of the elastic behavior of

materials, a torsion experiment has been implemented. The test may be run from

computers located in the classroom, where students collect data, and analyze it using the

classroom computers. The testing machine is located in another building on campus. A

description of the process will be given in the paper.

Key Words:

Mechanical properties, remote testing, testing, experiments, and torsion

Prerequisite Knowledge:

Physics, mathematics, chemistry, and elastic behavior of materials

Objective:

To develop remote experiments via the Internet that realistically demonstrate the

various principles of material behavior taught at the sophomore engineering level to a

large number of students, who do not have access to a laboratory facility.

Equipment and Materials:

Uniaxial testing machine, specimens, LabView®, Data Socket, camera, intemet

connection, computers connected to the internet.

Introduction:

The experiment to be described was pilot tested using sophomore level

engineering students at Texas A&M University as part of the NSF Foundation Coalition

effort to restructure the sophomore level engineering courses.1 Since these courses are

taught to a large number of the engineering students, and because the time allowed for

135
laboratoryactivitiesin a sophomorelevel classwaslimited,themethodof deliveryof

theselabswasof primaryimportance,aDuringthefall 1998semester,thetestingmachine

wasactuallyrolledto theclassroomandfour classsectionseachof about60students

weredividedin teamsof eight studentsandeachteamranatensiontest.Fromthe

students'point of view,obtainedfrom evaluationcomments,theprincipaladvantagesof

theteamlaboratoryactivitiesincludedhands-onexperienceandbeingableto connectthe

materiallearnedin thelectureswith apracticaltestingapplication.Ontheotherhand,the

limited timeavailableresultedin only afew membersperteamhavingachanceto

participatein theactualexperimentation,confusionin thedatareduction,too muchwork

in a shortperiodof time, andtoomanystudentsperexperimentalapparatus.Many of the

mentioneddisadvantageswereaddressedby consideringremoteexperimentationusing

LabVIEW. Duringthespring1999semester,studentswereableto remotelyruntension

testsandobtaindatain atime,efficientmanner.ThispaP3erwill describethedevelopment

of atorsionexperimentusingthesamebasicequipment.

Procedure:

The experiments developed were carried out using an Adelaide Testing Machine

(ATM), equipped with computer-controlled loading and data acquisition systems. The

testing machine is shown in Figure 1.

i@

Figure 1. ATM Test frame used for tension, compression, and torsion tests.

The ATM is capable of testing specimens in tension, torsion, and compression. The unit

is controlled with a PC through two XT-type cards. One card is an AnalogDigital (A/D)

converter from ATM, Inc. which acquires voltage readings from the axial load cell, the

torsion load cell, and the extensometer. The extensometer is used to obtain strain

measurements on a fixed reference length of 1 in. The voltage readings from the A/D

136
card are then converted at the software level into pounds (lb.) for the axial load

measurements, in-lb for the torque measurements, and in/in for the strain measurements.

The other card is a servo-controller card from Galil Motion Control, lnc. that is

used to send commands to the servomotors of the ATM. The servomotors move the

crosshead vertically for axial testing and rotate the lower jaw grip for torsion testing. This

card also detects encoder counts to give the axial displacement of the crosshead during

tensile/compressive loading and the rotation of the jaw grips during torsion testing. The

ATM was originally set to operate using an MS-DOS program from ATM, Inc.

It was not possible to run a test in a remote experiment mode using the available

MS-DOS software, and therefore LabVIEW was adopted. Fortunately there were existing

LabVIEW drivers for the Galil servo-controller card available from the Galil Motion

Control's Website. The A/D card did not have existing LabVIEW drivers but this

memory-based card was easily accessed by using the InPort/OutPort VI's available in

LabVIEW. Technical information about the A/D card was obtained from ATM, Inc.

Once the drivers were written, LabVIEW provided a framework where a test could be

customized according to a required experiment. That is, a VI was created where a

deformation history was specified by sending the corresponding commands to the

servomotors. This VI provided the advantage that it could be easily modified to specify

any deformation history composed of axial and rotational motions. The deformation data

and the tensile, compressive, or torsion data were then recorded during the time period

when the servomotors were set in motion.

Comments:

Once the ATM was set to be controlled with LabVIEW and with the recent

development of the DataSocket application, a remote experiment was readily

implemented. This time the ATM did not need to be rolled into the classroom. The ATM

and the controller/server computer remained at the Materials Laboratory, and the students

remained in the classroom. During the first pilot test, teams of four students each ran tests

in succession using a single client computer, as shown in Figure 2. The Virtual

Figure 2. A team of students performing a remote tension test

137
Instrument(VI) exampleusedwasdesignedtoberepeatedimmediatelyafterarun.This

wasachievedby specifyinga single-cycleloadinghistory for arun.Thespecimenwas

simplyattachedonceby anoperatorattheMaterialsLab andthespecimenwasloaded

cyclically asmanytimesasneeded.Thestudentoperatorselectedthemaximum angular

displacement of the crosshead and also the rotational speed for a torsion test. After

setting these two parameters, the VI was executed remotely from the client computer at

the classroom. The data points were plotted on the screen concurrently with the motion of

the servomotors. In addition to the control panel of the VI, the student operators were

able to see a video of the current experimental setup to obtain a feedback of what is

currently happening physically at the Materials Laboratory. For the video feedback

NetMeeting from Microsoft was used. At the end of the cycle, the data points were stored

for the students.

Figure 3. Control panel in LabVIEW used for the remote tension tests.

Example

Data collected using a solid A1 cylinder is shown in Table 1. The left-hand two

columns represent the data collected during the experiment, while the remaining columns

are data calculated from the first two columns. A plot of all stress-strain data is shown in

Figure 4. If only the elastic portion is considered, Figure 5 illustrates this portion of the

data. The shear modulus determined from the above data for a solid cylinder of A1 is

2 x 10 6 psi, which compares with 3.6 x 10 6 as given in Callister's book (Material Science

and Engineering An Introduction, 4 th ed. pg. 114). The lower value may be attributable to

the fact that a solid cylinder was tested rather than a thin walled cylinder.

138
Table 1. Data collected and analyzed for an AI cylinder.

Torsion Ex _eriment

Revolution Torque

in-lb

0 -13.0466

0.0008 -10.9876

0.0015 -8.7243

0.0024 -6.6148

0.0031 -5.0698

0.004 -3.6331

0.0048 -2.8748

0.0056 -1.5293

0.0064 -0.1554

0.0072 1.2603

0.008 2.8319

0.0088 4.4034

0.0095 5.9086

0.0104 7.1869

0.0112 8.4873

Shear Shear

Radians Torque Strain Stress

in-lb in/in psi

0 -13.0466 0 -4254.69

0.005027 -10.9876 0.000209! -3583.22

0.009425 -8.7243 0.000393 -2845.12

0.01508 -6.6148 0.000628 -2157.18

0.019478 -5.0698 0.000812 -1653.34

0.025133 -3.6331 0.001047 -1184.81

0.030159 -2.8748 0.001257 -937.514

0.035186 0.001466 -498.727

0.040212 0.001676

-1.5293

-0.1554 -50.6782

0.065345

0.045239 1.2603 0.001885 411.0023

0.050266 2.8319 0.002094 923.5241

0.055292 4.4034 0.002304 1436.013

0.05969 5.9086 0.002487 1926.881

0.002723 2343.753

0.070372

7.1869

8.4873 0.002932 2767.833

Shear Stress vs. Shear Strain (0.15 rev./min,

0.025 rev.)

.-. 6000

.m

._ 4000

2000

-2000

-4000

-6000

-8000 "[ I I

0 0.002 0.004 0.006 0.008 0.01

Shear Strain (in/in)

Figure 4. Plot of the shear stress vs. the shear strain for the data shown in Table l.

139
Shear

4000

3000

2000

1000

0

-1000

-2000

Stress vs. Shear Strain = 2E+067- 3652

R2 = 0.9973

0 0.0005 0.001 0.0015 0.002 0.0025 0.003 0.0035

Shear Strain

Figure 5. Elastic portion of the shear stress vs. shear strain data.

Using this setup, students did not need to worry about the technical details of

setting up the experiment but rather just focus on the underlying physics of the problem

and the interpretation of the results. The students were already familiar with the

experimental setup since they had weeks before visited the laboratory performed a tensile

test. The class was able to complete testing in a less than half the time it required with

sending student groups to the laboratory. Efficiency can be further increased by using

existing classrooms where every two students can share a laptop. This arrangement will

be managed in the future using the various client/server features of DataSocket. The

technical support received from National Instruments for the implementation of

DataSocket was extremely helpful during the development of this test. The successful

delivery of the first pilot test was possible as a result of the combined efforts from the

Foundation Coalition Team at Texas A&M University and National Instruments.

Acknowledgements:

The authors would like to thank the National Science Foundation for their support

through the Foundation Coalition, Director Karen Friar, University of Alabama. Project

No. NSF EEC-9221460.

References:

1Malave, C.,"Teaming in the Integrated Curriculum of the Foundation Coalition at Texas A&M," ASEE

National Conference, Washington, D.C., June 1996.

2 Griffin, R. B., Everett, L. J., Keating, P., Lagoudas, D., Tebeaux, E., Parker, D., Bassichis, W. and

Barrow, D., "Planning the Texas A&M University College of Engineering Sophomore Year Integrated

Curriculum," Fourth World Conference on Engineerin_ Education, Oct. 95, St Paul, MN, vol. 1 pp. 228-

232.

3 Yapura, C. L., Griffin, R. B., Lagoudas, D. C., "Mechanics of Materials Experiments Via the Internet,"

NIWeek 99 Conference Proceedings, Austin, TX, Aug. 1999.

140
LECTURE WORK NOTES FOR

INTRODUCTORY MATERIALS

ENGINEERING CLASSES

Stephen Krause

Department of Chemical and Materials Engineering

Arizona State University

Tempe, Arizona 85287-6006

Telephone: 480-965-2050

e-mail skrause@asu.edu

141
Stephen Krause

142
Lecture Work Notes for Intr_uctory Materials En_L_eermg Classes

Stephen Krause

Department of Chemical and Materials Engineering

Arizona State University

Tempe, AZ 85282

Abstract

This paper describes a method for delivering technical subject matter by a method

referred to as "lecture work notes". It is a method that is a variation on traditional

Nackhoard lectures but enhances student involvement and participation in the lecture.

The "lecture work notes" method essentially consists of a framework of complete

handout-based lectures in which critical components of the lecture content are left as

open spaces. These are then filled out during the lecture by individual students who

participate in the development of the instructor's overhead lecture writings. This

approach aliows more time and attention to be devoted to the "active analytical content"

of the lecture rather than the "passive descriptive content" of the lecture. Students are

very positive about the use of the method and it appears that student performance in

understanding material can be enhanced

Key Words: Lecture work notes, teaching methodology, student interaction

Introduction

A wide variety of approaches are used today to communicate subject matter in

materials engineering and other technical courses. Although the majority of classes

taught in the Materials Engineering Program at Arizona State University rety upon the

traditional blackboard lecture method, this approach is being supplemented by methods

which increase the involvement of students during the class lecture. These methods,

which are not unique and are being used to varying extents at other institutions, include

classroom demonstrations, individual student exercises and experiments, and team-based

exercises, experiments, and projects. One variation of these methods that can be used is

"lecture work notes", which is the subject of this paper.

The Lecture Work Note Methe, d

The "lecture work note" method is a reiatively straightforward evolution of my

teaching technique. My approach to teaching has shifted from textbook-based

blackboard lectures, to textbook-based blackboard lectures supplemented by handout

notes, to textbook-referenced "lecture work notes". These notes essentiaUy consist of a

143
skeleton of complete handout-based lectures in which critical components of the lecture

content are left as open spaces. These spaces are then filled out during the course of the

tecture by individual students as they participate in the development of the instructor's

overhead lecture writings. So the form of the notes might include the framework of a

diagram, but with the contents of the diagram being filled in during class from overhead

projector generated by a dialogue between the instructor and students. This approach

aLlows more time and attention to be devoted to the "active analytical content'' of the

lecture rather than the "passive descriptive content" of the lecture. I find that this

method is particularly useful for class sizes beyond 30 to 40 students, since students are

more involved in the lectures and the time savings creates the possibility of more student

interaction. Developing subject matter in computer format also allows easy sharing and

modification of content by other instructors teaching similar content

An example of this approach is in the teaching of Miller indices. In the "lecture

work notes" the orthogonal XYZ axes are shown with a unit cell cube inscribed upon

them. In one set of exercises six or eight examples of conversion of a set of MiLler

indices to a given plane in a unit cell are worked through with input from the students.

The next topic is, conversely of course, working through a set of exercises of determining

Miller indices from planes as represented in unit cell diagrams. Although using this

approach may seem to be a somewhat trivial variation on the usual blackboard lecture, it

actually proves to be a good tool for facilitating and communicating the concepts. Some

benefits with respect to this type of exercise are; significant amount of time conserved

from not drawing the axes and unit cells or the planes in unit cells; improved accuracy of

the drawings by the instructor; and improved accuracy of the drawing student. An

example of a blank sheet and a filled-in sheet of "lecture work notes" from the Miller

indices topic are shown at the end of this paper.

The "lecture work note" method proves to be especially valuable in lectures on

subject matter which relies heavity on complicated figures or equations. This is

particularly true for topics such as crystal structures, phase diagrams, and

microstructures. In the presentation of equations that describe the physical processes

represented by the parameter symbols, names and units is included in the notes while an

equation itseff and the functional relationships of the physical parameters (directly

proportional, inversely proportional, exponential, etc.) are then presented in lecture. This

approach allows time to engage student input into the development of an equation and

relationships. The dialog, questioning, and postulating with students improves their focus

and understanding. In the student evaluation of the "lecture work notes" one frequent

comment was, which I did not anticipate, that the natural organization of the notes was a

valuable tool in studying subject matter for quizzes and tests because students could

easily compare their notes a particular page from the standardized "lecture work notes".

144
Students also commented that they have more time to listen, think, and participate

without having to copy blackboard notes at a frenetic pace

The physical body of the "lecture work notes" is not excessive, requiring typically

four to eight pages per lecture for 20 lectures. This consumes about 100 to 150 pages of

material for a given course. I find that a significant amount of open space adjacent to

figures, diagrams, and equations is useful so that students have an opportunity to record

thoughts, comments and dialog on the notes. The "lecture work notes" prove to be

particularly valuable for diagram-intensive courses such as Materials Characterization

Techniques. When discussing instrumentation components for techniques, such as Auger

spectroscopy, scanning electron microscopy, etc., the use of diagrams in the particularly

useful for students. The drawback with these figures, of course, is that copyright

permission must be obtained from publishers if they are taken from text books. If drawn

by computer by the instructor, or by a teaching assistant, they are time consuming and/or

expensive. Another valuable resource for figures is from sites on the internet, although

copyright permission would probably have also be obtained from the source. I mention

this since I have noticed that some of the clearest and most descriptive diagrams that I

have ever seen in students' term papers have been directly downloaded from the intemet.

Short assessments of the use of "lecture work notes" in comparison with the

blackboard lecture method in three or four classes were conducted. The results are

generally quite positive with the tinding that more than 75% "prefer" or "strongly prefer"

the "lecture work notes". The impact on student learning is less certain. In examining

the final grades for introductory classes of 50 students in Structure and Properties of

Materials there were shifts in the distribution. Roughly speaking, there was a shift

upwards of a moderate fraction of B grades to A grades (which increased by about 50%),

white the fraction of C grades was roughly unaffected. One interpretation of these results

is that the "lecture work notes" did not help the less motivated students in the C range,

but they did help improve some of the more motivated students in the B range.

Sunmmry and Conclusions

A brief summary of the advantages and disadvantages of the "lecture work notes"

method of teaching materials engineering courses is summarized below. The advantages

of the "lecture work notes" technique include":

* improved legibility of instructor handwriting and figures

* decreased student and instructor writing fatigue

* increased participation of students in class

* increased attention of students during fflting in notes

* increases student involvement and opportunities for interaction in large classes

* increased highlighting of important content and concepts

145
* computerized class content and subject matter is easily shared and modified by

other instructors teaching the same or similar course content

* significant savings of class time with reduced writing and figure drawing

* student thinking, questioning, and dialogue increases with time savings

Some disadvantages of the "lecture work notes" technique include":

* students can have more time to daydream by rote copying of overhead material

* "work notes" can be copied and distributed to students not attending class

* modification and development of "lecture work noes" is time consuming

* obtaining copyright permission or redrawing of figures is time consuming

* moderate amount of paper is consumed with figures and blank spaces in

"lecture work notes"

Overall, the "lecture work notes" technique has proven to be a useful method to

communicate subject matter in materials engineering which improves student

participation in lectures and enhances student learning. It has the flexibility to be adapted

by instructors with varying content in lecture notes while a computerized format allows

easy sharing and modification of content by other instructors teaching courses with

similar content.

146
PLANES IN UNIT CELLS

MillerIndices- givetheodcntationofa givenplane.They areenclosedin"roundedbrackets( ) and are

dd_Jte, d by the integer indices ( h k 1 ). They represent the reciprocals of the intercepts of a plane at the unit cell

axes. Negative indices are denoted by a bar above the index number.

Examples - ( 1 1 2 ) Mistakes - [ 1 1 2 ], _

(i2i)

(01o) i2i

( 1 I 0 ) BCC close packed pla_ne

"( 1 1 1 ). FCC close packed plane ( -1 1 0 )

(I,I,0)

(246)

•DRAWING THE PLANE FROM MILLER INDICES -A RECIPE

1) Choose origin in unit cell

2) Invert indices

3) Locate & mark intercepts (go back to origin after marking each intecept)

4) Connect intercepts

Example.

(iii)

i)

2)

3)

4)

(ioo)

i)

2)

3)

4)

(ilO)

i)

2)

3)

4)

Z

x/

zI

Y

Y

Y

(ilO)

1)

2)

3)

4)

(012) _'

1)

2)

3).

4)

(ooi)

i)

2)

3)

4)

x/

X

Z

z]

z

Y

Y

Y

147
/.

Miller Indices - give the orientation of a given plane. They are enclosed in "rounded brackets ( ) and are

de_{(stedby the integer indices ( h k 1). They represent the reciprocals of the iatercepts of a plane at the unit ceil

axes. Negative indices are denoted by a bar above the index number.

Examples - ( I 12 ) Mistakes . [ 112(_ 1_,) r'ano,, _¢a.c.tt_

(121) - a

(010) 121 rto b ro.x.k_

( I 10 ) BCC close packed plane

(1 1 1) FCC close packed plane (-110) 710 (_

( 1, 1, 0 )

_;'_- _ (246)

\t 1) Choose origin in unit cell

"2) Invert indices

3) Locate & mark intercepts (go back to origin after marking each intecept)

4) Connect intercepts

Example / "

X/_ 4) ,.

1)¢_ ooo

z) 7

3) X'=-_',.y--f,_',[

4)

(100)

Z

Z

(110)

3)X:J y=lz,_,_

Y

(o1_)

1) o" _-ool ,_(

3)×-_ y-(z--'_ I/

&r"

4) X/

Z

(ooi)

1) 0 % oo I X,._

.,111

2).LL

0 O

.L

-I "1

3) 4) _,,/,- oo a=-X/_

a

148
A DECADE OF CERAMICS OUTREACH

Mark Glasper

Director of Communications

The American Ceramic Society

P. O. Box 6136

Westerville, Ohio 43086-6136

Telephone 61.4-794-5898

e-mail mglasper @ acers.org

149
Mark Glaspher

150
A DECADE OF CERAMICS OUTREACH

The American Ceramic Society initiated an outreach program ten years ago with a focus on

precollege education. Over the years various support materials have been developed, including

brochures, periodic tables, bookmark sets, videos and ceramic sample kits. Individual members,

selections and student branches were invited to participate in the program. Currently, members

around the world are sharing their time and the Society's materials with students to raise their

awareness of ceramics.

The highlight of the ACerS outreach effort has been the recent two-and-a-half-year tour of the

traveling exhibit, "The Magic of Ceramics". The ten-case exhibit traveled more than 7500 miles

to eleven different cities nationwide. More than 250,000 people have seen the exhibit in its

venues which have mostly been science and technology museums. The exhibit now resides

permanently in the Ross C. Purdy Museum of Ceramics, sponsored by Saint-Gobain, at ACerS

headquarters in Westerville, Ohio.

Even more recently, ACerS has published two books that further outreach efforts. "The Magic

of Ceramics", by David Richerson, and "Boing-Boing the Bionic Cat", by Larry Hench, are

excellent examples of what can be done to raise ceramics awareness and its engineering

discipline.

Examples from the outreach program, including experiments, will be highlighted.

151
152
MODERN MODEL AIRPLANES

AS FLYING COMPOSITES

L. Roy Bunnell

Southridge High School

Kennewick, WA 99338

Telephone 509-734-3800

e-mail bunnro @ksd.org

153
Lo Roy Bunne_

154
MODERN MODEL AIRPLANES AS FLYING COMPOSITES

L. Roy Bunnell

Southridge High School

Kennewick, WA 99336

Key Words: Composites, Model Airplanes, Balsa, Radio-Controlled Airplanes

Prerequisite Knowledge: Students should have some instruction in elements of

aerodynamics, including lift, drag and stability, as well as basic composite concepts such

as stressed-skin reinforcement. The concepts in this paper are transferable to various

academic levels, in that a type of model airplane can be chosen that is compatible with

virtually any student population. The performance of any model chosen can then be

enhanced by use of composite materials and construction, if it does not already include

such. Since the materials are relatively delicate, students with some experience in model

building will be far ahead of their peers in building skills. The instructor will have to

adjust for this diversity, perhaps by having the more experienced act as peer coaches.

(Students who are avid modelers may even be able to coach the instructor, to some

extent)

Objective: To give students hands-on experience with weight-sensitive structures and

provide a vehicle for composite concepts.

Equipment and Materials: Appropriate model kits, chosen from the list below, plus

hobby knives, sandpaper, suitable adhesives and small amounts of glass cloth and

graphite fabric, for reinforcement.

Gliders: Basic Balsa Glider, #7286, approx. $1/glider

Basic Rubber-Powered: Delta Dart, #9927, approx. $ t .50/plane

More Advanced Rubber-Powered, #9925, approx. $3/plane

The kits and catalog numbers above are from Theta Technology Education, P. O. Box 70,

Mound, MN 55364, one of many possible suppliers.

Introduction: Many in this audience probably had some early experience with model

airplanes in their youth. In my own first experience during the 50's, model airplanes

were built almost entirely of a light and strong wood, balsa. The structures were usually

open frameworks to minimize weight, and models were consequently quite delicate. The

framework was covered with light and stiff paper-based covering materials such as

Silkspan, or special tissue papers that were then wet to shrink them tight. Shrinkage of

the covering materials frequently created warps in the rather spindly structures, which

had large effects on the model's flying ability. I doubt that I personally ever made a

straight wing in those days.

In the many years that have passed since those days, the model airplane hobbyist

has taken good advantage of new materials, combining them effectively with the balsa

that has always been the main material of construction. Competition, even to the

National level, has provided a driving force for continuous improvement in models. The

modeler is driven by a need to produce structures of minimum weight but maximum

155
strengthandstiffness,andto accomplishthis nowhasaccessto materialssuchasthosein

thepartiallisting below:

Cyanoacrylate Adhesives, to provide adequate strength while adding only very

small amounts of weight.

Fast-Curing Epoxies, to provide higher strength for high-stress areas of the

structure, at some weight penalty.

Polyester (and other) Covering Materials, to provide a tough and light covering,

shrink by application of heat but unlikely to warp structural framework, with a heatactivated adhesive and with as-supplied colors eliminating the need for heavy paint

pigment. These covering materials are stiff and strong enough to function as stressed

skins.

Very Light Glass Cloth (weight/area as little as 0.7 oz/sq, yd.), bonded to

structures with epoxy for stressed-skin stiffening

Polystyrene Insulation, cut accurately to the airfoil shape with a hot, tightly

stretched nichrome wire and used as the core for stressed-skin composite wings.

Graphite Fiber, available in several forms such as roving and fabrics of various

weight/area, used for selective stiffening or wing reinforcement.

Procedure: After assessing the interests and craftsmanship of the group, choose an

appropriate model type, from the following list:

Hand-launched gliders, generally all-balsa and with a wingspan <18 inches

Rubber-powered gliders, about the same size as hand-latmched

Both of these model types are available as kits from various vendors, one of

which is listed above. Assemble the kits, following instructions exactly. Cyanoacrylate

adhesives and 5-minute epoxy will decrease building time. Previous to or during

construction, point out to students that the the balsa wood in the kit has been chosen

according to its density, since strength is proportional to density. As an exercise, students

might be instructed to calculate the density of the different balsa supplied with the kit,

correlating the density with the stress levels expected during launch and flight. For

instance, horizontal and vertical stabilizers, if built of solid balsa, will be built from very

low-density wood, while wing wood will have a higher density. Fiberglass cloth can be

purchased that is extremely light, see list above. This cloth can be added to stress points

in the airplane, attaching it with medium-curing (30 min) or slow-curing (3 h) epoxy. Of

course, in weight-critical structures, the additional material added for the sake of strength

must be minimized.

Once the models are constructed and carefully examined for straightness and

soundness, they should be balanced as per kit instructions. Generally, modeling clay

added to the nose of the planes provides an easily adjustable material for balancing. On a

very calm day, planes can be taken outside and test-glided, and any final adjustments

made. Finally, fly the planes in the manner intended, evaluating them by timing several

flights and averaging, to find the best-flying planes in the class.

Comments: One of the most important features of this learning activity is that it is FUN.

Though many of today's students have little or no experience with model airplanes, the

156
general concepts presented here are quite simple and students should be able to achieve

impressive results if the model types are chosen appropriately. It would probably be best

to start with a model type that the instructor considers too simple for the students, in

order that they build successful planes. In subsequent years, the chosen model can be

changed if necessary to align with student skill/experience. The model types chosen are

admittedly simple, but could be used with students up to high-school age. The lack of

experience of almost all of today's students will help to avoid feelings of d6j_t vu.

Demonstration: At NEW:2000, I wilt have a hand-launched radio-controlled glider,

constructed so as to embody all of the concepts in the paper. This glider will be shown

and, if outdoor space and weather permits, demonstrated.

References:

Ross, Don. Flying Models: Rubber, CO_2,_Electric, & Micro Radio Control, Markowski

International Publishers, I998. ISBN 0-938716-54-9

157
158
MICROWAVE DIELECTRIC ANALYSIS

OF SELECTED MATERIALS

J. N. Dahiya

Physics Department

Southeast Missouri State University

One University Plaza

MS 6600

Cape Girardeau, Missouri 63701

Telephone: 573-651-2390

e-mail dahiya@physics.semo.edu

and

J. A. Roberts

Physics Department

University of North Texas

Denton, Texas 76203

e-mail roberts@unt.edu

159
J. N. Dahiya

16o
Microwave Dielectric Analysis of Selected Materials

J. N. Dahiya

Physics Department

Southeast Missouri State University

One University Plaza, MS 6000

Cape Girardeau, MO 63701

dahiya@physics.semo.edu

and

J.A. Roberts

Physics Department

University of North Texas

Denton, Texas 76203

roberts@unt.edu

Key Words

Polar molecules, dielectric relaxation, resonant cavity, perturbation of fields

Prerequisites

Knowledge of electromagnetic theory and basic components of electronics

Objectives

1. To understand the function of a microwave spectrometer for dielectric studies.

2. To understand the normalization procedure using Slater's equations.

Summary

Microwave dielectric response of trichloroethane and chlorobenzene is studied using a

microwave spectrometer. The spectrometer is operated in the x-band of frequencies between 8.3

to 12.4 GHz using a Varian X-13 klystron. A cylindrical resonant cavity is used as a tool in the

microwave spectrometer. The cavity is operated in the TE011 mode and the perturbations of the

electric field inside the cavity is based on the Slater's equations. Using these equations and

normalizing the fields, the real and imaginary components of the complex permittivity are

determined at 10.1 GHz. The relaxation times for these materials are determined using Debye' s

equations.

161
Introduction:

The microwave spectrometer employed in this experiment has been used very extensively in

dielectric studies of different materials [1-4]. The details ofthe spectrometer can be found in

those references in which dielectric relaxation mechanism has been studied using a resonant

cavity in T01_ mode. The main purpose of using this mode is because of a very high Q-value for

the resonant cavity. This makes the cavity very sensitive in terms of its perturbation of electric

field. Similar techniques using resonant cavities in different modes have also been used [5-9]. A

computer control system is used to monitor the temperature of the microwave resonant cavity

very precisely.

Theory, Procedure, and Analysis:

Dielectric behavior of a material reveals very important information regarding the electrical

nature of that material. It is measured in terms of the polarization capabilities of that particular

material.

The dielectric constant of a polar liquid arises from the orientation of molecular permanent

electric dipoles and the electrical distortion of the molecules. Both of these effects can be

expressed in terms of a quantity P, the polarization, or dipole moment per unit volume of a

continuous material:

P=(No IV)_ o (1)

where 3o is the average dipole moment per molecule, No is Avogardro's number, and V is the

molar volume. The polarization process always involves rapidly forming polarization that

consists mainly of electronic polarization, and may also involve slowly forming polarization.

Debye in his theory [1O] explained the relaxation phenomenon and showed that the polarization

of a dielectric medium in an electric field might arise from the partial orientation of permanent

molecular dipoles by the field as well as from the distortion of electronic orbits in the molecules.

The theory starts with an assumption about the time variation of the polarization in response to a

step function removal of field. The simplest assumption is of an exponential decay

P(t) = Poe -t/_ (2)

where r is the relaxation time. The physical meaning of such decay is that the rate of change of

polarization is proportional to the difference between the instantaneous polarization and its final

value. This relaxation assumption is often used in the theory of the return to equilibrium of a

perturbed system.

Normalization Of the fields in Slater's Equations:

A sample of material under study (trichloroethane and chlorobenzene) is placed into a capillary

tube that in turn is attached to a micrometer drive. The presence of the sample causes the

perturbation of the fields inside the cavity and as a result of that there is a frequency shift Af and

162
Q-change of the resonant cavity. The frequency shifts and Q-changes are related to the real and

imaginary parts of the complex dielectric constant through the perturbation equations [4]. Since

the precise nature of the field in the cavity could not be ascertained relative values of e' and 6"

are calculated for molecules in this investigation with respect to water as a standard. Constant

parameters to be used in the Slater perturbation equations [4] are obtained for water. The

g--\

in Af and A[O ) as a function of mass of the sample residing in the cavity can be changes

expressed by a simple power-law equation [11]. The data is fitted to equations of the form

&f = A + B(Am) N (3)

(4)

where A and C are the intercepts, B and D are the slopes, Am is the fraction of sample mass

advanced into the cavity and N is a constant which depends upon the geometry of the electromagnetic fields inside the sample holder and the cavity. A computer analysis was made of the

experimental data in order to determine what power of N led to a "best fit" for the data. The best

value of N appeared to be 1.6. A plot of some of the data using N = 1.6 is shown in Figure 1.

Using equations (3) and (4) along with Slater's perturbation equations (5) and (6) given below

Af= _'-1 I/_., - .Edv

A(Q)= c'-l lf;'_'Edv (6)

one can write

and

Af = B = fo F(E) (7)

(Am)

1

A--

Q

(am)

- D fo C" F(E)

(8)

Where F(E) is given by

163
F(E) =

Iv_._adV (9)

And is a functional form of how the field interacts with the sample, Ea and E_ are the fields as

applied to the cavity and the sample inside the cavity, E is the total field of the system, Af is the

frequency shift, and Q is the quality factor of the resonant cavity respectively, and fo is the

resonant frequency of the cavity.

All the samples are placed into small capillary tubes of constant diameter of 2mm to eliminate

any geometrical effects. Now ifF(E) is of the same form for all the samples, there arises a

characteristic Bx and Dx for each sample of x. If Bw and Dw are the corresponding values for

water one can express relative values for dielectric material as follows:

and

B_ _'_- 1

Bx e'-I (10)

D_ ,9[

D_ e" (11)

Equations (10) and (11) are used to calculate e' and e" for trichloroethane and chlorobenzene

using literature values of e' = 61.3 and e" = 29.7 for water at 25°C at a frequency of 10.1 GHz.

A similar procedure is used to calculate the real and imaginary parts of the complex dielectric

constant for these materials as a function of temperature. The thermal bath used in this

experiment is very sensitive in terms of maintaining the temperature of the material when it is

going through the phase change. A computer interface system is used to control the amount of

air going through the thermal bath and in turn cooling the microwave resonant cavity to the

desired temperature. Tile block diagram of such a system is shown in Fig. 2. The microwave

dielectric response of trichloroethane and chlorobenzene as a function of temperature at

10.1 GHz is shown in Figs. 3-6. The microwave resonant cavity is very successful in studying

the dielectric relaxation behavior of trichloroethane and chlorobenzene. The thermal bath used

in this experiment is very sensitive and with this technique temperature can be varied by 0.1 °C

intervals.

.

.

References

Dahiya, J. N.: Dielectric Properties of Germanium and Silicon as Determined in the

Microwave Field. J Mater. Educ., 13_, 1991, p. 367.

Dahiya, J.N.: Dielectric Behavior of Superconductors at Microwave Frequencies.

NIST Special Publication 822, 1990, p. 145.

164
. Dahiya, J. N., and Freeman, R, W.: Computer Interfacing of a Microwave Resonant

Cavity for Temperature Measurements During Dielectric Relaxation. Computers in

Physics, Jul/Aug. 1989, p. 49.

o Dahiya, J. N., Jani, S. K. and Roberts, J. A.: Phase Transition Studies in Polar and

Non-Polar Liquids at Microwave Frequencies. J. Chem. Phys. 74(6), 1981, p. 3609.

. Hong, K. H. and Roberts, J. A.: Microwave Properties of Liquids and Solids Using a

Resonant Microwave Cavity as a Probe. J. Appl. Phys., 45(6), 1974, p. 2452.

. Arlt, G., Hennings, D., and de With, G.: Dielectric Properties of Fine-grained Barium

Titanate Ceramics. J. Appl. Phys., 58(4), 15 August 1985, p. 1619.

, Gerson Robert: Dielectric Properties of Lead Titanate Zirconate Ceramics at Very

Low Frequencies. J. Appl. Phys, 31 (9), 1970, p. 1615.

. Poirier, M., G. Quirion, K. R. Poeppelmeier and J. P. Thiel, "Microwave Study of the

High-Tc Superconductors Lal.sSr0.2CuO4," Phys. Rev. B 36(7): 3906(1987).

. Lurio, A., mad Stem, E. : "Measurements of the Dielectric Constant of BaTiO3 Single

Crystals in the Paraelectric Region at x-band." J. Appl. Phys., 31, 1960, p. 1805.

10. Debye, P. : "Polar Molecules", Chemical Catalog, New York, 1929, Chapter 5.

11. Haniotis, Z. and Gunthard, H. H., Agnew, Z., Math. Phys., 20, 1969, p. 771

165
4 .q3e

FREOUEHCYSHIFT 4.08

FREOUEHC¥ SHIFT

3.28

2.4e

1.6B

8.8e

8.e8 'L't ' i

8.ee 8.e8 16.@8

HASS

24_8e

3.2B

2,40

! .68

e.se

e.8i) ' ' | -i

8.8e 4B. ee 88'. ee 12e. ee

HASSx:_([. 6 )

Figure 1.

resonant

Frequency shift (MHz) as a function of mass (mg) and mass**(l.6) for water at a

frequency of 10.1 GHz.

Thermocouple

Microwave

Cavity

Figure 2. Experimental setup for dielectric studies showing the computer control system

166
10

9

2

-80-60-40-20 0 20 40 60 80 100

Temperature (°C)

Figure 3. Frequency shifts of the resonant cavity as a function of temperature for a sample of

trichloroethane at a microwave frequency of 10. t Ghz.

4

N

_3

g2

0

-80 -60 -40 -20 0 20 40 60

Temperature (°C)

Figure 4. Changes in the Q-factor of the resonant cavity as a function of temperature for a

sample of trichloroethane at a microwave frequency of 10.1 GHz.

167
A

N

"1"

_

_

J

-7

2-

-8O -60 -4O

I 7 7 7

-20 0 20 40 60

Temperature (°C)

Figure 5. Frequency shifts of the resonant cavity as a function of temperature for a sample of

chlorobenzene at a microwave frequency of 10.1 Ghz.

_- 1.5

gl

_0.5

0 I

-65 -45 -25 -5 15 35 55

Temperature (°C)

Figure 6. Changes in the Q-factor of the resonant cavity as a function of temperature for a

sample of chlorobenzene at a microwave frequency of 10.1 Ghz.

168
LEARNING THE PRINCIPLES OF GLASS

SCIENCE AND TECHNOLOGY FROM

CANDY MAKING

Himanshu Jain

and

Isha H. Jain

Department of Materials Science and Engineering

Lehigh University

5 East Packer Avenue

Bethlehem, Pennsylvania 18015-3195

Telephone: 610-758-4217

e-mail hj00 @ Lehlgh.EDU

169
Biography:

Himanshu Jain is the T.L. Diamond Chair Professor of Materials Science and

Engineering at Lehigh University. Earlier he was a researcher at Argonne and Brookhaven

National Laboratories. He has developed both graduate and undergraduate courses in materials

science, specializing in glasses and ceramics. He is a recipient of the Zachariasen award for

outstanding contribution to glass research, Doan award by his Department's Senior class for the

most influential teacher, a Fulbright Fellowship for lecturing and research at Cambridge and

Aberdeen in UK, and a Humboldt Fellowship for research in Germany. He is a Fellow of the

American Ceramic S6ciety.

Isha Himani Jain is a flRh grade student at Governor Wolf Elementary School in

Bethlehem, PA. A great enthusiast of math and science, she initiated the present work as her

Science Fair project a year ago, and then completed the remaining experiments during past

summer.

170
Learning the Principles of Glass Science and Technology

from Candy Making

Himanshu Jain and Isha H. Jain

Department of Materials Science and Engineering

Lehigh University, Bethlehem, PA 18015

Key Words:

Glass formation, glass transition, nucleation, crystal growth, crystallization, viscosity,

fiber drawing, glass-former, network-modifier, chemical durability, candy, hardness.

Prerequisite Knowledge:

The steps of candy making can demonstrate numerous principles of physical chemistry

and materials science & engineering, which are typically taught from Middle School through

College level. Notwithstanding, we discuss the experiment assuming that the student has

completed High School level chemistry. Additional knowledge of the principles of binary phase

diagram is desirable. The experiment is well suited for an Introductory course in Materials

Science and Engineering, typically taken by most engineering majors. It will be also an excellent

paradigm for a course on glass science or technology.

Objectives:

To observe and understand the following principles of glass science and technology:

1. When a homogeneous melt is cooled sufficiently slowly, one obtains a single crystal. Fast

cooling yields polyerystalline solid. Glass is formed on increasing the cooling rate further,

when crystal formation is fully suppressed.

2. Surfaces, insoluble impurities, mechanical agitation, bubbles, etc. in the melt can act as

nucleating agents for crystal formation. These should be avoided if the goal is to obtain glass.

3. The addition of a modifier oxide to a glass-former oxide decreases the ability of the melt to

form glass.

4. The glass-forming ability of a melt may be enhanced by increasing

components.

5. The addition of a modifier oxide generally deteriorates the chemical

mechanical properties of glass.

6. It is possible to draw glass fibers from melt but within a narrow range of viscosity, which in

turn can be controlled by varying the temperature.

the number of

durability and

Equipment and Supplies:

1 one-quart stainless steel pan.

12 metal tablespoon

1 laboratory balance (or fluid measuring cup at home)

1 metal tray to hold hot candies (up to _175 °C/350 °F)

1 laboratory or good quality candy thermometer that reads up to - 205 °C or 400 °F.

5 pounds of granulated cane sugar

16 oz.-bottle of corn syrup (e.g. Karo syrup available in supermarkets)

Drinking water

171
20 molds for casting the candies. The metal containers of Tea Light candles (small cookie cutters

will also work well).

Four 8-oz. glasses.

Crystal candy, readily available as an aggregate of large clear, colorless crystals

Background:

Both the glass making and the candy making developed independently as empirical art in

ancient times. Interestingly, the two technologies share same underlying principles, which can be

learnt conveniently using kitchen tools. Common glasses such as the ones used in windows,

tableware, bottles, etc. are based on silicon dioxide (SiO2) (a.k.a. silica or common sand) as the

main constituent. 1 Silica is one of the best glass-formers. It forms glass readily when cooled

from the molten state. Among glass forming oxides it has one of the highest glass transition

temperature (Tg) 2, strength, chemical durability, etc. In spite of its superior properties, however,

pure silica (or quartz) glass is not used much due to its very high melting temperature (Tin),

which makes cost of its manufacture prohibitively high. Commercial solution to this problem is

to lower the melting temperature by adding alkali or alkaline earth oxides as flux (typically 13-

18 wt% of Na20 and 8-13 wt% (CaO+MgO)). These additives, which alone do not form glass

easily, decrease the melting temperature by forming eutectics. They break the network

connectivity of silica glass, and therefore, are known as network modifiers. In general, the

addition of a modifier also deteriorates chemical durability, lowers Tg and decreases glassforming ability of the glass. Therefore, a glass engineer must optimize the glass composition

depending on the use and acceptable cost of the final product.

The candy making process serves as an excellent illustration of these principles of glass

science and technology. Here sugar (i.e. sucrose, C12HE2OH with Tm=186 °C) is a good glass

former and water (H20 with Tin=0 °C) a good modifier in a candy, just like SiO2 (Tm=1723 °C)

and Na20 (Tm=1275 °C), respectively, are in a common glass.

Experimental Procedure:

Caution: The present experiments require working with high temperatures and hot liquids, which

should be handled with appropriate insulation to avoid burning.

Note: The following recipe is suggested by the National Confectioners Association for making

rock candy using sugar, corn syrup and water as the key ingredients. We break it down in three

experiments by working with (a) sugar alone, (b) mixture of sugar and water, and finally (c) the

mixture of all three ingredients.

Main steps of the suggested recipe:

• Put 3.75 cups ofgranulated sugar (~820 g), 1.5 cups of Karo corn syrup (-480 g) and 1 cup of water (-200 g)

into the saucepan, and heat gently until the sugar has dissolved, constantly stirring with the tablespoon.

• Bring to a boil and cook, without stirring, until the temperature reaches 310 F/154 °C.

• Remove from heat (and add candy flavoring and food coloring - not important for our experimenO.

• Pour mixture onto a foil lined bakingpan.

• Immediately remove foil from baking pan by sliding the pan out from under it.

• As mixture cools, cut with scissors

t The broad scientific definition of glass is: It is a non-crystalline or amorphous solid. Common glass is but one subclass of this wide range of solids that may include metals, polymers as well as ceramics.

2 Roughly defined as the temperature below that the supercooled liquid behaves as a solid.

172
Experiment A. Formation of candy from pure sugar,

a. Take 410 g sugar in the pan and start heating gradually on hotplate or electric cook-top at

Low-Medium temperature setting. Insert thermometer and monitor the temperature of sugar.

Use the spoon to stir sugar, thus maintaining uniformity of temperature. Note: the

thermometer bulb should be in the middle of sugar, and away from the bottom of the pan.

b. Continue heating and stirring until all the sugar has melted. The stirring speed should be such

that solid and molten parts mix together. Note the temperature (Tin) when all the sugar has

just melted, giving its melting point.

c. Stop stirring the melt. The temperature during this time should not be allowed to increase to

avoid excessive browning of the melt and bubble formation, which occur from the

decomposition of sugar.

d. Cast two candy samples (#A1 and #A2) by taking one and three, respectively, tablespoons of

the molten sugar and pouring into two separate molds that were placed on the metal tray.

Make a note of the physical appearance of the samples as they cool to room temperature

(RT), especially about the transparency, presence of small white crystals and/or bubbles, and

whether solid or liquid.

e. Turn the botplate off. Attempt drawing fiber by slowly taking the spoon away from the

syrup. Continue this process as the temperature of syrup decreases to solidification when

fiber drawing becomes impossible. Make a note of fiber drawing ability as a function of

decreasing temperature. Estimate the temperature (Ta) at which: fiber drawing ability is

maximum.

f. Compare the appearance of samples #A1 and #A2 with that of crystal candy that is also made

of pure sugar.

Experiment B. Determine the effect of addition of water to sugar on the processing of candies.

a. Put 4I 0 g sugar and 100 g water in the pan (these ingredients are in the same ratio as in the

original recipe), and begin heating while stirring the melt. Monitor the increase of

temperature as sugar dissolves. Note the temperature (T_) at which all the sugar dissolves in

solution.

b. Continue heating and stirring. Note the temperature (Tb) at which the syrup begins to boil.

Cast candy from the syrup (sample #Bt). Make a note of the physical appearance of the

candy as it cools to room temperature, especially about the transparency, presence of small

white crystals, whether solid or liquid, and relative viscosity at RT if it remains fluid.

c. Boil the remaining syrup, while also stirring, until the temperature increases by 5 °C i.e. it

reaches T2=Tb+5 °C. (A temperature increase of 10 °F may be used if working with a

Fahrenheit thermometer, typically used in kitchen.) If solid sugar is deposited at the edges of

the syrup, scrape and stir it into the liquid. Cast candy from this more concentrated syrup

(sample #B2). Make a note of the physical appearance as before.

d. Continue repeating the previous step, casting a new candy for each 5 °C (or 10 °F) increment

in temperature (sample #B3, #B4, ... etc.), until the temperature reaches -170 °C (338 °F).

Every time use a clean spoon to cast a new sample.

Experiment B(a). Determine the effect of stirring on the processing of candies made from sugar

and water.

173
According to Objective #2, mechanical disturbances, the interface between the melt and

surface of the pan, etc. can help nucleate the crystal formation. To verify this statement, repeat

all the steps of Experiment B except that this time do not stir the solution after the sugar has

settled at the bottom of the pan (at - 200 F). Try to cast the samples (#Bl(a), #B2(a), #B3(a),...

etc.) when the melt is at the same temperature as in Experiment B.

Record the changes in samples as they cool to room temperature, making special note of

any differences compared to the corresponding B samples.

Experiment C. Determine the effect of addition of corn syrup to (sugar + water) mixture on the

processing of candies.

This experiment is essentially a repetition of Experiment B(a), with the exception that

now the ingredients also include 240 g corn syrup, in addition to 410 g sugar and 100 g water. To

begin, place all the three ingredients in clean pan, follow all the steps of Experiment B(a), and

note corresponding observations.

Experiment D. Effect of processing conditions on the properties of candies.

The experiments described below are designed so that little specialized equipment is

needed. If appropriate equipment is available, such as for measuring hardness or viscosity, the

students are encouraged to obtain quantitative data.

Hardness or Chewy character. The samples would have a wide range of hardness from

brittle solid to a watery liquid. To make a comparison of this property, use a paper clip. Open the

clip up from one end, providing one sharp end, and one bent end of the wire. Use the sharp end

for testing solid samples by inserting the pin under approximately the same force. Compare the

size of the dent thus created on different samples. For liquid samples, use the bent end of the pin.

Dip it into the liquid and take it out, noting the relative force needed to do so.

Durability in water. Select one each of the A, B, B(a) and C samples (say the one cast

from the melt at -150 °C or 302 °F). Determine their weight (still in mold), using laboratory

balance, and place them in separate 8-oz. glasses with 200 g tap water. (Note: all the water

should be at the same temperature). Drain the water out after 1 h. Take the samples out, dry and

weigh them again. This is a static experiment, so the sample and water should not be disturbed.

Calculate the respective weight loss from dissolution in water. The loss of a sample's weight

occurs from dissolution at the top surface that is exposed to water. Since the mold cross-section

area is the same for all samples, the weight loss is inversely proportional to the durability.

Therefore greater is a sample's weight loss, lower is its durability.

Some of the glassy or partly glassy samples may devitrify rather slowly. In that case,

make a note of slow changes in the physical appearance of such samples over the next several

days.

Record the qualitative information in the Table below by assigning relative grades 1

through 5, when possible. For example, in the Transparency column write 1 for an opaque and 5

for a completely transparent sample.

Example of Results:

Melting Temperature of sugar, Tm = 344 °F

Temperature of maximum fiber drawing, Td = 190 °F

Temperature where the solubility of sugar in water is 410 g / 100 g, Ts = 210 °F

Boiling temperature of the initial (sugar + water) syrup, Tb = 220 °F

174
Temperature at which 410 g sugar dissolves in 100 g water + 120 g corn

syrup, Ts' = 228 °F

Boiling temp. of the initial (sugar + water + corn s3a'up) solution, Tb' = 220 °F

Weight of as cast sample #A1

Weight of sample #A1 after dissolution in water

Weight loss

=10.1 g

= 9.1g

= 1.0g

Weight of as cast sample #B5

Weight of as prepared sample #B5 after dissolution in water

Weight loss

= 22.7

= 17.9

= 4.8

g

g

g

Weight of as east sample #B 10(a)

Weight of as prepared sample #B10(a) after dissolution in water

Weight loss

= 16.5

= 15.1

= 1.3

Weight of as cast sample #Ct0

Weight of as prepared sample #C10 after dissolution in water

Weight loss

= 19.8

= 18.7

= 1.1

g

g

g

Table of Observations

Sample # and

time since

i casting

#A1

#A2

Casting

Temp.

Transparency

3.5

#B1 228 5--> 4--->2.5

#B2 236 5--_ 3-+2.5

Crystallinity

1.1

1.5(?)

Relative

Hardness (H) or

Viscosity (V)

H: 5

H: 5

1-41.5 Cryst.+Liq.

1_2

#B3 242 5--_ 2 2---_3

#B4 256 5--->1 2---M--_4.5

#B5 3--->1 4--)4.5

#B6 2--->1 5--->5

#Bl(a) 228 5--_4.5---_2.5 1---M--M.2---_

1.5

#B2(a) 238 5---M.5--+2.5 1--M.5-+1.5

248

258

5--->2.0

5---M---_2.0

1--_2---_2.5

1_2.5

#B3(a)

#tM(a)

Cryst.+Liq.

H:3

Cryst+Li q.

H:4 Cryst+Liq.

H:4.5

Polycrystal

H:5.0

polycrystal

Cryst.+Liq.

Cryst.+Liq.

V:4

Cryst.+Liq.

H:2

Comments

Red'brown solid. Many bubbles.

Sample used in durability test.

(Fig. 1)

Dark brown solid. Very large

number of bubbles. (Fig. 1)

Prior to casting the hot syrup

contained small white crystals

(Fig. 2) ,,

Liquid t_action decreases as

#B 1(a)-+ #B3(a)

Bubbles t_ormon pouring in mold.

175
Sample # and

time since

castin_

#B5(a)

#B6(a)

#B7(a)

#B8(a)

i

Casting

Temp.

268

Transparency

5-_2.0

Crystallinity

1---_3---_3.5

298 5---M.0 1---_2---_3

#B9(a) 300 5--_3.0---M.5 1--+1.5-+2.5

-+2.5

#B 10(a) 310 4.5--_4.5 1.5--_ 1.5---_2

-+2

#B1 l(a) 317 5---_5.0 1--_ 1.1---M.2

#B12(a) 338 545.0

#C1 228 5 1

238

248 5 1

t , ,

258 5 1

268 5 1

278 5 1

288 5 '1

298

300

310

320

330

#C2

#C3

#C4

#C5

#c6

#C7

#C8

1---_1

#C9

#CIO

#C11

#C12

#C13 340

1

Relative

Hardness (H) or

Viscosi_ (V)

Non-sticky

H:3

Non-sticky

H:2.5

Non-sticky

H:3

Non-sticky

H:3

Less sticky

H:3.5

More sticky

H:3.5

Sticky

H:4

H:4.5

V:2

Thick syrup

V:3

V:4

H: 1.5

V:4.5

Chewy

H:2.5

Sticky

H:3

H:3.5

H:4

H:4.5

5 1 H:4.5

5 1 H:4.5

5 I H:-5

5 1 H:5

Comments

Colorless liquid.

Many bubbles form on pouring in

mold. Colorless liquid.

Many bubbles form on pouring in

mold.

Light yellow liquid. Bubbles form

on casting.

Light yellow liquid. Bubbles form

on casting.

Yellow liquid. Shows crystal

growth easily.

Light brown liquid. Shows crystal

growth easily.

Brown' liquid. I_ess bubble

formation on casting.

Dark brown liquid. Some

bubbling.

Can draw fiber at RT

Wrinkling of surface later

Crinkling of surface.

Colorless. Surface crinkles after

casting

Hue of yellow. Wrinkled next

day.

Pale yellow glass

Light yellow glass

Yellow glass.

Yellow glass

Light brown glass

Brown glass

Brief Discussion:

Note: The following information is primarily for instructors. It is provided as an illustration of

anticipated results and discussion of students" observations,

1. The melting temperature of pure sugar is observed to be 344 °F, which is lower than the

value reported in literature, possibly because the present value was measured in a somewhat

supercooled state.

2. The casting ofpure molten sugar in a mold at RT gives a glass-like candy (A samples). It is

light to dark brown, and translucent to opaque depending on the bubbles produced

presumably from the decomposition of sugar (Fig. 1). The cast candy takes the shape of the

176
mold which contrasts with the faceted crystals of rock candy Therefore we infer that the

cast candy is a non-crystalline or glassy solid

When crushed by a hammer the cast glassy candy behaves as hard and brittle as the

crystalline rock candy suggesting that most likely there is no major difference between their

mechanical properties

(In a separate experiment we grew sugar crystals from slow evaporation of saturated

solution of sugar in water over a couple of weeks (Note Kits for this experiment are

available from popular science stores) Many orders of magnitude longer time was available

for sugar molecules in solution to organize in large crystals than the time of solidification of

the cast Therefore we infer that shorter time for solid formation from disorganized liquid

state promotes non-crystalline structure.)

3 From Experiment B we observed that at room temperature the (sucrose + water) mixture

consisted of both liquid syrup and undissolved solid sugar On slow heating and stirring the

solid phase disappeared at Ts=210 °F Therefore the solubility of sugar in water must be

increasing with temperature Furthermore at 210 °F its value should be about 410 g per 100

g H20

4 On heating the solution after all the sugar has dissolved the single phase syrup begins to boil

at Tb=220 °F On further heating the syrup continues to boil and at the same time the

temperature also increases This can happen only if boiling causes a change in the syrup

composition Since water has a much lower boiling temperature than sucrose we infer that

boiling (at 220 °F) causes preferential loss of water from the syrup In turn, the syrup

becomes increasingly viscous and concentrated with sucrose ultimately it would approach

the 100% sugar composition In a way the boiling temperature becomes an indicator of the

sugar content of the syrup Therefore the concentration of modifier oxide decreases in the

sample order #Bl(a) > #B2(a)> #B3(a)> #B4(a) etc Similar variation occurs among the

C samples

5 The stirring of syrup induces crystal formation, thereby suppressing glass formation Once

formed the crystals are difficult to dissolve back The crystalline solid preferentially formed

at the thermometer and pan-syrup boundary A comparison of B and B(a) samples clearly

shows that the samples east from stirred syrup crystallize much more easily than the ones

cast from unstirred solution (Fig 3) We were not able to obtain solid glass in B samples at

RT either we obtained a mixture of crystal and liquid phases (#B1 - #B4) or a chunk of

polycrystalline sugar solid (#B5 and #B6)

6 Within the B or B(a) series the appearance of most samples changed with time If the

modifier content was high, the formation of polycrystalline chunks ensued after casting

Figure 4 shows the crystal formation in B2 sample with increasing time With decreasing

modifier content the crystal formation decreased gradually if the sample was not stirred

Contrast Fig 5 vs Fig 4

7 At room temperature the glass forming ability increased with decreasing H20 modifier

content as shown by Fig 6 recorded about 12 hours after casting Here the samples Bl(a)

through B3(a) were a mixture of liquid syrup and polycrystalline solid sugar They did not

form glass With decreasing water content the transparency of the samples decreased as the

fraction of polycrystalline sugar increased However on further decrease of HzO content the

samples became increasingly more transparent Thus sample #B1 l(a) and #B12(a) remained

completely transparent and glassy These observations confirm similar behavior of the SiOz

Na20 system.

177
8 The viscosity of the molten syrup (just before casting) increased as water boiled off

gradually This occurred even as the temperature of observation i e the boiling temperature

increased 3 Also at RT the viscosity of liquid samples increased with decreasing H20

content These observations are best exemplified by the experiment C for which glass

formation was not a problem In this series the viscosity increased in the order #C1 < #C2 <

< #C13 (see Table) Clearly the addition of modifier oxide decreases the viscosity of glass

forming sucrose strongly The same statement is true for the SiO2 Na20 glass system.

9 The increase of RT viscosity with decreasing modifier content can be characterized as chewy

to hard candy If a candy is chewy and clear it means that its glass transition temperature is

below RT The less chewy is the candy much lower is its Tg than the room temperature

Thus the Tg of sucrose water glass decreases with increasing modifier content The same is

also true for the SiO2 Na20 glass system. In popular literature the hardness of a candy is said

to depend on the temperature at which the syrup was boiled before casting Now we know

that a more accurate cause of a candy s softness is the amount of water (the modifier) it

contains!

10 For the glassy candy below Tg such as #C7 #C13 hardness increased with decreasing

water content In other words the break up of network structure by a modifier decreases the

hardness of a glass as is also true when Na20 is added to SiO2

11 As the melt temperature decreases the melt viscosity increases and the ability to draw sugar

fibers (essentially making of cotton candy) increases (see Fig 7) However after a while the

ability to draw fibers becomes increasingly difficult These observations show that viscosity

of melt increases with decreasing temperature and only in a narrow range of viscosity (i e

the temperature) it is possible to draw long fibers

12 Since the duration and surface area exposed to water were about the same for the samples of

Experiment D the weight loss values indicate their susceptibility to attack by water The

results show that pure sugar glass is most durable among the four samples Addition of 1-120

modifier renders the glass more susceptible to the attack by water Some of this loss of

chemical durability of the sugar glass is recovered when corn syrup is added Very much

parallel technology is adopted for making common oxide glasses where the loss of durability

of silica by the addition of Na20 is regained by the addition of other oxides such as A1203

13 The polycrystaUine sample #135 showed much larger weight loss for two reasons (a) The

sample was inherently less durable than the glassy form, especially at the grain boundaries

(b) The sample was not a monolithic solid and was cracked Thus the surface area exposed to

water was larger than for the other samples

14 Overall the observations of Experiment C confirm the various conclusions that are derived

from Experiment B and B(a) In addition, we note that the viscosity of the liquid is increased

by the addition of corn syrup The three components are soluble in each other The intimate

mixing of sugar and corn syrup makes it difficult for sugar molecules to organize as crystals

The tendency of sugar water glass to devitrify is strongly suppressed by the addition of corn

syrup making it possible to obtain clear glassy candy at high modifier concentrations

Without the addition of corn syrup it will be too difficult to obtain chewy clear candies from

sugar water mixture alone

Acknowledgement The authors gratefully acknowledge the Diamond Chair endowment for

supporting this work

3 Contrary to this observation generally the viscosity of liquids decreases with increasing temperature

178
Bibliography:

1. Fundamentals of Inorganic Glasses, A.K. Varshneya, Academic Press, New York, 1994.

2. Chocolate Manufacturers Association / National Confectioners Association.

http://www.candvusa, org

179
For color photographs in this paper, please refer to the web page at:

http://www.lehigh.edu/_inmatsci/jain.html

Figure 1. Candies cast t_om pure molten sugar, showing different bubble density that determines

transparency. The figure in the middle is a magnified part of the one on the left. The right sample

is thicker and opaque. It has a much higher bubble density.

Fig.2. Small white crystals in the boiling liquid syrup, resulted from stirring action. These did not

exist in the unstirred syrup. Scale: Figure diag6nal = 14 crrL

180
Fig. 3. The figure shows the effect of melt-stirring on glass formation. The samples in top row

were stirred before casting, whereas the ones on bottom row were not stirred.

Fig. 4. Growth of sugar crystals in high modifier content mixture. The figure shows B2 sample

with increasing time from left to right.

il_ iili_ _i _'

i i i ,_ :ii ̧ _ .

Fig. 5. Growth of sugar crystals in low modifier content mixture. The figure shows B10(a)

sample with increasing time from left to right.

181
Fig. 6. Demonstration of increasing glass-forming ability with decreasing modifier content from

left to right. Unstirred sugar+H20 samples from Experiment B(a). Sample #Bl(a) is mostly,

liquid with a few crystals floating. The fraction of crystals increases in #B4(a) and #B8(a), the

latter being mostly solid. #10(a) is mostly solid glass with a few crystalline regions. Finally, the

last sample (#B12(a)) is just solid glass.

Fig. 7 Large changes in fiber drawing ability with a change in temperature just by a few F.

182
DETERMINATION OF VISCOSITY USING A

FALLING SPHERE VISCOMETER

Harvey Abramowitz

Department of Engineering

Purdue University Calumet

2200 169 thStreet

Hammond, Indiana 46323

Telephone: 219-989-2473

e-mail habramowitz @worldnet.att.net

183
Biographical Information:

Harvey Abramowitz received a B.S. in Materials Science from the Henry Krumb School of

Mines, School of Engineering and Applied Science, Columbia University. He completed M.S.

and D.Eng.Sc. degrees from the same school in extractive metallurgy/mineral engineering. Prior

to coming to Purdue University Calumet, he was a Research Engineer at Inland Steel Research

Laboratories and Visiting Professor at the University of Missouri, Rolla. This year, he is a

Visiting Scholar at Northwestern University. Dr. Abramowitz is an Associate Professor of

Mechanical Engineering and is responsible for the materials sciences courses. Major areas of

research are the treatment of waste streams for metal recovery and the cryogenic treatment of

steels.

184
Determination of Viscosity Using a Falling Sphere

Viscometer

Harvey Abramowitz

Department of Engineering

Purdue University Calumet

Hammond, IN 46323

Key Words:

Viscosity, Falling Sphere Viscometer, Glycerin

Prerequisite Knowledge:

The student

1. should be familiar with PC's and spreadsheets.

2. should be familiar with micrometers and dial calipers.

Objectives:

.

2.

3.

4.

5.

To introduce the student to the concept of viscosity.

To demonstrate one method for determining viscosity of a liquid.

To determine the viscosity of glycerin.

To introduce the student to experimental uncertainty.

To introduce the use of standards (i.e., literature values) to verify experimental results.

Equipment and Supplies:

.

2.

3.

4.

5.

6.

7.

8.

9.

10.

11.

12.

Scientific Grade Glycerin (Fisher Scientific)

2000 ml Graduated Cylinder

Balance

Stopwatch

Micrometer

Dial Caliper

Temperature Meter with J or K Thermocouples

Thermometer

Meter or Yard Stick

Cotton Gloves

Rubber Gloves

Small Spheres of Various Materials and Sizes

a. Materials: Stainless Steel, Brass, and Glass

b. Sizes (diameters) Stainless Steel (440) 1/8", 3/16", 1/4"

Brass 1/8"

Glass 3 and 6 mm

185
13.

14.

15.

16.

Forceps

PCwith SpreadsheetProgram

Masking Tape, or

Marking Pen that can write on glass, such as an overhead marking pen

Introduction:

Viscosity is an important property of fluids (liquids and gases). It can be considered a measure

of the resistance of a fluid to flow. Knowledge of a fluid's viscosity can be critical in optimizing

industrial applications and processes. As examples, it is important to know the viscosity of

(1) liquids used as lubricants, (2) molten metals and slags when smelting, refining, and

processing metals, and (3) glasses during their production and processing. Perhaps one of the

most familiar applications of viscosity knowledge is in the consumer's choice of an automobile

engine oil. Nowadays, a single all season weight oil is typically used. However, it wasn't that

many years ago that different weight oils were used in the summer and winter seasons. This was

due to the fact that viscosity is highly temperature dependent, and, for a liquid, decreases as the

temperature is raised. Hence, a heavier weight oil was used in the summer and a lighter weight

engine oil used in the winter.

Theory:

The following explanations have been excerpted from Poirier and Geiger.l'2

Newtonian Fluids

Consider a fluid between two parallel plates (Fig. 1). The upper plate is stationary and the lower

one is set in motion with a velocity V at time zero. From experience, it is known that the fluid

adjacent to the plates wilt have the same velocity as the plates themselves. Hence the fluid

adjacent to the lower plate moves with a velocity V, while that adjacent to the upper plate has

null velocity. As time proceeds, the fluid gains momentum, and after sufficient time has elapsed

steady state is reached, in which, in order to keep the lower plate in motion with the velocity V, a

force F must be maintained, and an equal but opposite force is exerted on the stationary plate.

y vx(y,t)

r

x v v v

,,Vx(y)

t J

t = 0 Lower plate set Small t Velocity buildup Large t Final velocity

in motion in unsteady flow distribution in

steady flow

Fig. 1 Laminar flow of fluid between parallel plates

186
At steadystate,for platesof areaA, andlaminar flow, the force is expressed by

F V

- rl-;. Eq. 1

A Y

where Y = distance between plates, and

1"1= constant of proportionality

The force system as described is pure shear, and the force per unit area (F/A) is the shear stress.

At steady state, when the velocity profile is linear, V/Y exactly equals the constant velocity

gradient dvx/dy and the shear stress Zyx between any two thin layers of fluid may be expressed as

dvx

"Cyx= -I]-- Eq. 2

dy

Equation 2 may alternatively be interpreted in terms of momentum transport. Picture the fluid as

a series of thin layers parallel to the plates. By the shearing action each layer causes the layer

directly above it to move. Thus, momentum is transported in the y-direction. The subscripts of

"Cyxrefer to this direction of momentum transport (y) and the velocity component being

considered (x-direction). The minus sign in Eq. (2) reflects the fact that momentum is

transferred from the lower layers of fluid to the upper layers, that is, in the positive y-direction.

In this case, dvx/dy is negative, so that the minus sign makes q:yx positive. This follows the

generally accepted convention for heat transfer, in that momentum flows in the direction of

decreasing velocity, just as heat flows from hot to cold.

The period between t = 0, when the lower plate is set into motion, and large t, when steady state

is reached, is called the transient period. During the transient period, Vx is a function of both

time and position. The empirical relationship described is known as Newton's Law of Viscosity,

and defines the constant of proportionality, rl, as the viscosity.

The units ofrl are given in both SI and English units, because both are still in use.

N m -2

rl = (m s-l)(m -1) = N s m -2 Eq. 3

lbf _-2

11 = (ft hr-1)(f_ -1) -- lbf hr f_-2 Eq. 4

(lb mft hr -2 )(ft -2 ) = lb m hr_ 1 ft_ 1 Eq. 5

or rl = (ft hr -1)(ft-1)

In the cgs system of units, thepoise (P) is used, in which

187
1 poise (P) = 1 dyn sec cm -2

-- 1 gm cm sec 2 see cm -2

= 1 gm sec -1 cm -1

The centipoise (cP) is probably the most common unit tabulated for viscosity. It equals 0.01

poise, and is the viscosity of water at 20.2 °C (68.4 °F). Thus the value of the viscosity in

centipoises is an indication of the viscosity of the fluid relative to that of water at 20.2 °C.

Viscosity in N s m-2 is 103 times viscosity in cP.

Falling Sphere Viscometer

If a sphere is falling through a liquid, it is possible to calculate the viscosity of the liquid. In

order to do so, a force balance on the sphere is made (Fig. 2).

fw

Fig. 2 Force Balance on Sphere Falling Through a Liquid

The forces acting upwardly on the sphere are the buoyant force (Fs) and the drag force (FK).

The force in the downward direction (Fw) is due to the weight of the sphere. These forces

have the following values:

Fs = 4_R3pg Eq. 6

3

which is the force exerted even if the fluid is stationary.

FK = 6_rlRV t Eq. 7

which is the force associated with fluid movement, and is commonly known as Stoke's Law for

creeping flow around a sphere. Stoke's Law applies over a very narrow range of conditions such

as those present in this experiment, where small spherical particles are moving through a

stagnant fluid.

188
4

and Fw = -nR3psg Eq.8

3

where

Theforcebalanceis:

R = sphereradius

p = fluid density

g = accelerationdueto gravity

I"1= viscosity

Vt = terminalvelocity

Ps= spheredensity

Fs+ FK= Fw Eq. 9

or 43_R3pg+6rcrlRVt=4 nR3psg Eq. 10

4 _R3g(p s_p)

Therefore, 1]= 3 Eq. 1 1

6nRV t

or

,q=2R2g_ gP ) 9V t

Eq. 12

This result is valid only if 2RVtp/rl is less than approximately unity.

2RVp <1 Eq. 13

11

The above quantity is known as the Reynolds (Re) number and is typically between 0.1 and 0.2

for this experiment.

If the column containing the fluid has a finite diameter, the column boundaries will indicate an

apparent terminal velocity higher than that obtained for an infmite fluid. The measured velocity

should be corrected as follows: 3

Vt=(I+2"4D) Vm_ Do Eq. 14

where Vt = terminal velocity in an infinite fluid

Vm = measured terminal velocity

D = ball diameter

Dc = column diameter

189
Experimental Procedure:

.

2.

3.

.

5.

.

.

.

Fill a 2000 ml graduated cylinder with glycerin.

Measure the temperature of the glycerin with a thermometer or thermocouple.

Choose a ball material and size. Try 5 or 6 different types of balls. Take a minimum of

three (3) balls for each type chosen.

Measure the diameters (D = 2R) of the balls using a micrometer or caliper.

Determine the average densities of these balls by dividing the weight of each ball by its

volume (4/3/_R 3 or/_D3/6).

If the balance used cannot weigh individual balls, weigh several balls together. Use at

least three (3) balls.

Mark two points on the cylinder so that they are at least 20-25 cm apart. Use tape or a

marking pen. Make sure that at the top point the terminal velocity is reached.

Let the balls drop one at a time in the fluid and measure the time for a sphere to fall

between the two points on the graduated cylinder using a stopwatch. The measured

terminal velocity is the distance between the two points divided by the drop time.

Calculate the fluid viscosity. Include the correction for terminal velocity.

Results:

Put the data and calculations into a spreadsheet. Use the following column headings:

Material Diameter (in) Diameter (cm) Weight (_) Volume (g/cm) Density (g/cm 3) Time (s)

V___m_ Dc (in) D__a_(cm) D/D_____Vtc_/.q___ Viscosity (P) Viscosity (cP) Temperature (°C)

Day/Group

The density of glycerin 4 is: 9 = 1.2613 g/cm 3 for 4 °C < T < 20 °C

For temperatures greater than 20 °C, the density will be assumed to also have this value. Room

temperature will not usually be greater than 25 °C.

Typical results are given in Tables I and II. The data on which these tables are based is found in

the Appendix.

Discussion:

The discussion should include answers to the following questions.

1. Compare the experimental results to published values. 5 Use the values below.

0 12,110

6 6,260

15. 2,330

20 1,490

190
o

°

°

.

25 954

30 629

Plot this data to see the strong dependence of viscosity on temperature (Fig. 3). Do a

linear interpolation to find the reported viscosity for the actual temperature of the

experiment.

Compare the average experimental viscosity to the reported viscosity. Include an error

analysis.

Viscosity is strongly dependent on temperature. To obtain values for comparison

purposes, values of viscosity between 20 and 25 °C are calculated using a linear

interpolation (Table 111). For this experiment with T=22 °C, the average rl = 1126 cP

with an overall error of 12%.

Is the experimental viscosity a function of the sphere materials?

Based on Table I, it appears that the glass spheres led to twice the error value of either

brass or stainless steel The viscosity should be the same regardless of the material

Is the experimental viscosity a function of the sphere size?

Tables I and H in conjunction with Table 111, show that the greatest error occurred using

the O.6 cm diameter glass spheres. Viscosity should be independent of sphere size.

Obtain data from other groups. Is the experimental viscosity a function of temperature?

When more than one group performs this experiment, a range of experimental

temperatures will result, especially if the groups do these trials on different days.

viscosities determined should depend on the temperature at measurement.

The

What are the possible experimental errors that could account for any differences between

the experimental and published values?

A number of sources that may account for any errors have been identified These are:

(a) Contamination of the glycerin has appeared as the biggest source of error. Water

absorption can drastically lower the viscosity, by as much as 50%. During the

course of even 1⁄2 hour of experimentation, the viscosity may steadily decline with

exposure to the atmosphere. If the balls are handled without gloves, natural oils

from the body may also adversely affect the results.

(b) lf the spheres are not perfectlv round, then the equations used would no longer

apply. An example of this may be the O.6 cm glass beads, since the error values are

twice those of the other materials. In the past, aluminum shot was used. This shot

led to errors much larger than any other spheres. Upon inspection, these balls

proved to be misshapen spheres. Consequently, aluminum shot is no longer used.

191
(c) Human errors in timing the descent of the spheres. For larger and denser spheres,

the time for descent is much smaller. Hence, any error in starting or stopping the

watch would lead to a greater error in the recorded time.

(d) When viewing the descent past the marking on the cylinder, if the experimenter's

eyes are not at the correct angle, there couM be some errors due to parallax.

6. Do you have any recommendations to improve this experiment?

(a) Check the balls for possible eccentricity by taking low magnification

photomicrographs.

(b) To reduce the wall affect variability, a funnel can be placed at the top of the

graduated cylinder to center the ball delivery.

(c) Measure the time for the balls to descend by videotaping the fall, followed by

analysis of the tape. Such a method could help to decrease the uncertainty in the

time measurements. However, the experiment would become more complicated and

expensive.

(d) Use much larger cylinders to obtain more accurate results. The purpose of this

particular setup was to show that acceptable values (within 12%) of viscosity can

be obtained using a very portable apparatus. This means that multiple stations can

be easily used in the laboratory. At Purdue University Calumet, this experiment is

done in a freshman engineering class (maximum of 25 students per laboratory

section) using a maximum of six stations.

Conclusions:

°

2.

The viscosity of glycerin at a temperature of 22 °C was determined to be 1126 cP, which

is within 12% of the published value.

The viscosity of a fluid can be experimentally determined using a simple falling sphere

viscometer.

References:

.

2.

3.

4.

5.

G.H. Geiger and D.R. Poirier, Transport Phenomena in Metallurgy, Reading, MA:

Addison-Wesley Publishing Co., 1973, pp. 5-7, 68-70.

D.R. Poirier and G.H. Geiger, Transport Phenomena in Materials Processing,

Warrendale, PA: TMS, 1994, pp. 4-6, 71.

E.H.Buyco and T.N. Tran, ME313 Lab-Manual, Fluid Mechanics Laboratory, Hammond,

IN: Purdue University Calumet, 1995, p. 65.

Handbook of Chemistry and Physics, 49 th ed., Cleveland, OH: CRC, 1968, p. C-338.

Ibid., p. F-40.

192
TABLE I

Viscosity of Glycerin as Function of Sphere Material

(T = 22 °C)

Material rl (cP) Error (%)

Brass 1160 9

Stainless Steel 1158 9

Glass 1043 18

AVERAGE of all trials 1126 12

TABLE II

Viscosity of Glycerin as Function of Sphere Size

(T = 22 °C)

Diameter (cm) _ (cP) Error (%)

0.3 1121 12

0.3175 1186 7

0.4763 1141 11

0.6 966 24

0.6350 1140 11

AVERAGE ofaH trials 1126 12

TABLE III

Viscosity of Glycerin as Function of Temperature

Linear Interpolation of Published Values

T (°C) _ (cP)

21 1383

22 1276

23 1168

24 1061

193
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196
TWISTY GLUE STICKS OR

TORSIONAL CHARACTERISTICS OF

HOT MELT ALL PURPOSE

GLUE STICKS

Alan K. Karplus

Department of Mechanical Engineering

Western New England College

1215 Wilbraham Road

Springfield, Massachusetts 01119-2684

Telephone: 413-782-1220

e-mail akarplus @wnec.edu

197
Bibliography:

,ALAN K, KARPLUS

Alan K. Karplus is Professor of Mechanical Engineering at Western New England College, Springfield,

Massachusetts. He has a Bachelor's degree for Tufts College, a Master's degree from Iowa State

University, and a Ph.D. from Colorado Sate University. He has been involved with the freshman

engineering program, coordinates the senior mechanical engineering laboratory program, has taught

Materials Science and supervises M.E. Senior Projects. His interests include materials and design. He is

a member of ASME and ASEE. He has contributed to the National Educators' Workshop and ASEE

Annual Conference for several years.

198
TWISTY GLUE STICKS

or

Torsional Characteristics of Hot Melt All Purpose Glue Sticks

Alan K. Karplus

Department of Mechanical Engineering

Westem New England College

1215 Wilbraham Road

Springfield, MA 01119-2684

Key Words:

Hot Melt Glue:Sticks, Polymer Properties, Torsion Tests

Prerequisite Knowledge:

Have an idea about how a thermoplastic hot melt glue stick can be twisted and reverse twisted without

thilure, and severely twisted to cause the stick to break apart.

Objective:

To work as a team member in the collection of data, to make plots for near constant rate twisting and

(reverse twisting) of traditional hot melt glue sticks, and to show features which are unique to these

thermoplastic products:

• Shear stress- shear strain plot

• Shear work done to fail sample

• Recoverable work and hystersis when sample is not failed

• Kate of loading

Equipment and Materials:

1. Ten inch long hot melt glue sticks. These are readily available at home centers as Arrow TM All

Purpose Clear Glue Sticx (Model AP10) which come in a box of 12 - 10 inch sticks. Some

suppliers _ carry a variety such as All purpose, Slow set, and white caulk/sealer/glue.

2. Torsion test apparatus. See the Appendix to this paper for construction of a torsion tester made

with Hex-angl erM, two 1⁄2 inch diameter Jacobs drill chucks, two 1⁄2 inch diameter fine thread 2 1⁄2

inch long bolts, miscellaneous bolts and washers, one 4 inch diameter Lazy Susan beating, and

chipboard disks.

3. C-clamps to hold the torsion tester base to a table.

4. Safety Goggles

5. Heavy work gloves

6. Load scale for loads to 10 pounds or 5 kg. A 20 Newton scale works, alsol

7. Vernier caliper.

8. Black or dark color Magic marker.

9. Data page with 25 lines and nine columns, Measurements are taken at 90 degree rotation

increments starting at a value of zero listed in the first column. The remaining columns are used

in pairs to record load and unload. Be sure to label columns and include units of measure

selected.

199
lo. A Spreadsheet such as EXCEL" TM. All work performed on the spreadsheet can be done by hand.

11. When the computations are to be done by hand, computation paper and several pieces of linear

graph paper with 20 divisions to the inch are needed.

Introduction:

The initial challenge is to hold a glue stick in your hand and to twist it about its long axis. This is

difficult to do! One objective is to design and build an apparatus which will twist the glue stick and

other samples. A torsion test apparatus has been designed from readily available parts. See the

Appendix for detailed construction instruction of an inexpensive (less than $50.00) torsion tester made

with Flex-Angle TM. This unit requires two disks: one 4 inch diameter and one 8 inch diameter each

with a circumferential groove so that the same load scale can be used and the applied torque can be

doubled. In case a different torque range is of interest another disk diameter can be made. For the All

Pu__u__oseArrow;Glue sticks the four inch diameter disk with torques of up to 2 inches times 10 pounds

can be applied. In fact, the load scale used was calibrated in NEWTONS so that a maximum of 2

inches times 20 Newtons divided by 4.448 Newtons per pound for 5.50 inch-pounds torque could be

applied.

Procedure:

A. Equipment Set Up:

The idea is to cut the 1⁄2 inch diameter 10 inch long glue stick into two 5 inch long sticks. Both 5 inch

long sticks are to be tested. On the surface of each stick draw a line parallel to the axis on the surface

with a 'Magic' felt tip marker. This is a reference line_

The First Test. is to twist the glue stick to failure. It is helpful to designate that the torsion wheel will be

loaded so that it rotates clockwise as the experimenter looks down on the wheel. Now place one 5

inch long stick into the tester by inserting - one at a time - an end of the stick all the way into the

bottom chuck (1 inch of insertion) and clamp the chuck hand tight onto the stick followed by four

revolutions of the Jacobs key in the chuck to assure capture of the glue stick end. Repeat this for the

second end into the top chuck (1 inch of insertion). Prior to tightening this chuck align the angle

position indicator 15 degrees counterclockwise to the 0 degree start position. This is to be sure to start

with a 0 angle reading. There are angle markings on the torsion wheel at 0, 90, 180, 270 and 360 or the

next zero (0) degree mark. Loads are to be read at each of these positions while the load is applied to

the 3 inch gage length glue stick and recorded. Note that on this primitive apparatus when six turns of

360 degrees torque wheel are anticipated a length of 4 inches times Pi (3.14157) times 6 or some 75

inches &fishing line coiled on the torque wheel will be unwound. Be sure to provide physical space for

this when mounting the apparatus on a table. Also be sure the table will not move. When the stick

breaks the wheel will spin. Gently and rapidly stop the spinning wheel by catching the disk to avoid

unwinding much fish line. A gloved hand works well for this.

The data is to be reduced to applied torque and angle of twist which are to be plotted first. After some

computations an engineering shear stress against shear strain plot can be made. The work done on the

sample can be computed and plotted, too. Also, the rate of load (torque) application can be

investigated and a plot made.

200
The Second Test is based on observations made of the data collected #l the First Test. Find the

'elastic' recoverable region of the response of the first five inch long stick to twisting. This will be

readily found when the load (torque) applied levels off, but does not fall in magnitude. The 'elastic'

recoverable region has been found.

The Second Test begins with loading and recording the load (torque) and angle of twist at each 90

degrees clockwise the stick twist up to and including the leveled-off load (torque). Then the sample is

to be unloaded wl-file the appfied load (torque) and angle of twist are recorded. As in the First Test.,

mount the 5 inch long stick with 1 inch inserted into each chuck for a 3 inch gage length is twisted with

load (torques applied at constant radius) recorded at 90 degrees of twist increment. The data is to be

reduced so that applied torque against angle of twist can be plotted for both the clockwise twisting

(UpLoad) of the sample when looking down on the top of the tester and the counterclockwise

(DwLoad) release of appfied torque on the glue stick. Then an engineering shear stress against shear

strain plot can be made after computation of shear strain and shear stress are made. Next the work

done on the sample and the energy stored by the sample can be computed and plotted against shear

strain. An hystersis coefficient can also be computed. Finally, the rate of clockwise applied torque

application in contrast to rate of released torque (counterclockwise rotation) can be investigated. This

latter part of the experiment up-twist and down-twist follows the presentation of Stretchy "Elastic"

Bands, Stretchy "Elastic" Bands II, and Stretchy "Elastic" Bands III presented as NEW: UpDate:

1997, 1998, and 1999 experiments, respectively by the author.

B. Computations:

The computations to be made for the First Test plot of applied torque against angle of twist to sample

failure requires the applied load to be multiplied by the Radius of the torque wheel which is two inches.

In addition, when English units are used a conversion from Newtons to Pounds is needed. The

clockwise angle of twist increments need to be replaced by total angle so that 0, 90, 180, 270, 0, 90,

180, 270, 0, 90, 180, 270 become 0, 90, 180, 270, 360, 450, 540, 630, 720, 810, 900, and 990

respectively. Assume six (6) revolutions are needed to twist the stick to failure so that 6 times 4 plus 1

lines on the data sheet are needed. Data sheet headings should be Twist Angle in degrees and Load in

Newtons (which becomes Torque). The plot can readily be made in a spreadsheet environment.

The Second Test plot of engineering shear stress against engineering shear strain is required. The angle

of twist is computed for the 1/4 inch radius test stick divided by the gage length of 3 inches selected in

this work multiplied by the angle of twist in radians (one radian equals 180°/Pi or 57.30°). There are

two Pi radians in one revolution. The shear strain is more complex and requires the application of a

relationship which multiplies the applied torque by the radius of the sample divided by the area polar

moment of inertia of the test stick. The polar moment of inertia is Pi (3.14157) times the diameter of

the test stick raised to the fourth power divided by 64.

Measure the twisting work done by the area under the curve of shear stress against shear strain (the

area under the UPLOAD line to failure). This represents the energy used to twist the glue stick.

Compute the area under the curves with trapezoidal increments and then, sum these increments.

201
A spreadsheet cellshouldbeusedto storeeachtrapezoidalareaincrement.Thetrapezoidalincrement

iscomputedbyformingtheaverageof 2stressesandmultiplyingbythechangein strain.Thetotalarea

underthecurveistheenergyandcanbefoundbyaddingtheincremental areasin acolumn.Be sureto

checkUNITSto besuretheyareconsistent.

Thecomputationsto bemadefortheSecond Test plot of applied torque against angle of twist includes

the recoverable portion of the glue stick. Again, this requires the applied load to be multiplied by the

radius of the torque wheel which is 2 inches. In addition, when English units are used a conversion

from Newtons to Pounds is needed. The angle of twist increments need to be replaced by total angle so

that 0, 90, 180, 270, 0, 90, 180, 270, 0, 90, 180 become 0, 90, 180, 270, 360, 450, 540, 630, 720, 810,

and 900 respectively. However, the maximum angle of twist is limited to the greatest recoverable twist

angle as assessed by evaluation of the First Test, presented above. Recall this maximum position occurs

when the torque starts to 'level-off,. There are now two curves: UPLOAD and DWLOAD. The plots

can readily be made in a spreadsheet environment.

The second plot for the recoverable portion of the glue stick evaluation of engineering shear stress

against engineering shear strain is required, the angle of twist computed for the 1/4 inch radius test

stick divided by the gage length of 3 inches selected in this work multiplied by the angle of twist in

radians (one radian equals 180°/Pi(3.14157) or 57.30°). There are two Pi radians in one revolution.

The shear strain is more complex and requires the application of a relationship which multiplies the

applied torque by the radius of the sample divided by the area polar moment of inertia of the test stick.

The polar moment of inertia is Pie times the diameter of the test stick raised to the 4th power divided

by 64. In this situation there are two curves: UPLOAD and DWLOAD.

When the work done, is considered, which is the area under the curve of shear stress against shear

strain increments for the area under the UPLOAD line are computed separately from the DWLOAD

line. These represent the energy used to twist and untwist the glue stick. Compute the area under the

each curve with trapezoidal increments. First the up-twist load curve and then the down-twist load

curve. A spreadsheet cell should be used to store each trapezoidal area increment, remember one for

the UPLOAD and one for the DWLOAD. A trapezoidal increment is computed by forming the

average of two stresses and multiplying by the change in strain. The total area under each curve can be

found by adding the appropriate incremental areas in a column, and is the energy related to each curve.

The difference between column totals (UPLOAD and DWLOAD) is found by subtraction and then

dMded by the total UPLOAD work to determine the portion of energy lost to internal friction or

hystersis. Be sure to check UNITS.

C. Test Activities:

I. The first activity is to build an apparatus for torsion testing. This is detailed in the Appendix.

II. The second activity, the First Test, is the evaluation of a glue stick under clockwise torsional

loading to failure.

I. Cut one 1⁄2 inch diameter 10 inch long glue stick into two 5 inch long sticks. Select one stick to

test to failure (This is the First Test.). Torsional loads are to be placed on the stick by pulling

on the load scale attached to the fish line wrapped around the torsion wheel and stored in the

circumferential groove on the wheel. Load scale (torsion) readings are to be taken at each 90

degrees of wheel rotation. It is best to note the wheel markings 0, 90, 180, 270 and 0 again and

202
prepare the data sheet angle of twist column as 0, 90, 180, 270, 0, 90, 180, 270, 0, 90, 180,

etc. The number of total turns can be counted later. Place safety glasses and gloves on the

spring scale operator, and prepare the recorded for writing the data on the data sheet.

The approach is to twist the stick at a near constant rate, recording the load to twist the stick

each added 90 degrees of twist until the stick is sheared apart and fails. At this juncture the

torsion wheel will spin rapidly until you gently stop it by clutching the wheel with a gloved

hand. Do not become frustrated if the fish line is inadvertently wrapped around the torsion

wheel several times. In preparation for the next test, a careful unwinding and wrapping of the

fish line into the torsion wheel grove works nicely, especially with patience. Assume six (6)

revolutions are needed to twist the stick to failure so that 6 times 4 plus 1 lines on the data

sheet are needed. Heading should be Twist Angle in Degrees and Load in Newtons (which

becomes Torque). Run the test.

2. The neXt task is to convert the recorded angular twist angles of 0, 90, 180, 270, 0, 90, 180,

270, 0, 90, 180, etc. into a ascending column of clockwise angles that increases with

increments of 90 degrees 0, 90, 180, 270, 360, 450, 540, 630, 720, 810, 900, etc. Once this has

been completed the appropriate load is converted to a torque in inch-pounds by dividing the

applied load recorded in Newtons by 4.448 Newtons per pound and multiplying by the torsion

wheel radius of 2 inches in the case of the 4 inch wheel. The converted data of angle of twist

(degrees) and applied torque (in-lb.) should then be charted with angle of twist as the

independent variable (horizontal or x-axis). Make an XY _ or Scatter Plot of this data. Label

this graph as Torsonal Load against Twist Angle for a General Purpose '/2 inch Diameter Glue

Stick

3. Compute shear strain for the angles of twist by dividing the radius of the stick (I/4 inches) by

the gage length (3 inches) and multiplying this value by the angle of twist in radians. The angle

of twist in radians is found by dividing the angle of twist by 180 and multiplying by Pie

(3.14157). For example 90 degrees is (90/180)'3.14157 or 1.57 radians. Next the shear stress

is computed for each applied torque expressed in inch-pounds. This calculation requires the

experimenter to multiply the torque by the radius of the twisted sample (% inches) and divide

the quantity by the polar moment of inertia. The polar moment of inertia which a property of

the geometry of the twisted member is found by dividing Pie (3,14157) times the diameter of

the twisted member raised to 4th power and dividing by 64 The units are pounds per square

inch. These computations are made for each angle of twist and accompanying torque to obtain

the corresponding shear strain and shear stress. Make an XY or Scatter Plot of this data. The

values of shear strain and shear stress are to be charted by plotting shear stress against shear

strain as the independent variable to obtain the General Purpose Glue Stick Shear Stress-Strain

Plot.

4. From the shear stress-strain data the computation of work done to fail the glue stick can be

found. The best approach is to apply the trapezoidal rule of integration to determine the area

under the shear stress-strain curve. On a spreadsheet this is achieved in two steps. First the

incremental work done over an increment of an angle of twist is computed, and second the

increments are summed. The units of work are inch-pounds per cubic inch of material (glue

stick). Make an XY or Scatter Plot of this data.

1 Be sure to make a plot of two variables and NOT a line chart as is the usual default setting on a spreadsheet.

203
. With the Applied Torque and Angle of Twist data the rate of loading can be assessed by

dMding an incremental change in Applied Torque by the corresponding increment of Angle of

Twist. Make an XY or Scatter Plot of this data. If the values computed over the range of

grains are constant, then the applied twisting of the glue stick was done in a 'constant' fashion.

Recall this was one objective for the experiment. Were you successful? Also check the

reference line on the sample. Is it still straight?

11I. The third activity, the Second Test, is the evaluation of the General Purpose Glue Stick for

recoverable features. The first step is to review the plot of Torsional load against Twist Angle plot (see

Part II item 2, above.) and determine where the curve 'levels-off,. The approach is to load the glue

stick and observe when the load (torque) starts to change and move from the peak of the recoverable

portion 2 of the glue stick with the recoverable region being in the vicinity of the "elastic limit" familiar

to those who test low carbon steel. Once this region has been 'sized', repeat the steps 1-5 in II above

with modification to collect DWLOAD load and angle of twist. Remember the first DWLOAD load is

the last UPLOAD load and both are at the same angle of twist.

1. Select the second half of the glue stick for the recoverable test - UPLOAD and DWLOAD the

glue stick (This is the Second Test.), Torsional loads are to be placed on the stick by pulling

on the load scale attached to the fish line wrapped around the torsion wheel and stored in the

circumferential groove on the wheel. Load scale (torsion) readings are to be taken at each 90

degrees of wheel rotation. It is best to note the wheel markings 0, 90, 180, 270 and 0 again and

prepare the data sheet Twist Angle column as 0, 90, 180, 270, 0, 90, 180, 270, 0, 90, 180, 270,

0, 90, 180 which is 15 lines. This discussion assumes there are 3 I/2 turns until the load 'levelsoff,. Label the next column UPLOAD (UPLOAD TORQUE) and the next column as

DWLOAD (DWLOAD TORQUE). Remember that the last UPLOAD load is the first

DWLOAD load and fill in the DWLOAD column is reverse as the stick untwists. Place safety

glasses and gloves on the spring scale operator, and prepare the recorded for writing the

data on the data sheet. The approach is to twist the stick at a near constant rate, recording

the load to twist the stick each added 90 degrees of twist until the stick load 'levels-off, at

M-rich point the DWLOAD begins. Run the test.

2. The next task is to convert the recorded angular twist angles of 0, 90, 180, 270, 0, 90, 180,

270, 0, 90, 180, etc. into a ascending column of angles that increases with increments of 90

degrees 0, 90, 180, 270, 360, 450, 540, 630, 720, 810, 900, etc. Once this has been completed

the appropriate load (UPLOAD AND DWLOAD) is converted to a torque (UPLOAD

TORQUE and DWLOAD TORQUE) in inch-pounds by dividing the applied load recorded in

Newtons by 4.448 Newtons per pound and multiplying by the torsion wheel radius of 2 inches

in the case of the 4 inch wheel. The converted data of angle of twist (degrees) and applied

torques (in-lb.) should then be charted with angle of twist as the independent variable

(horizontal or x-axis). Make an XY or Scatter Plot of this data. Label this graph as

Recoverable Torsonal Load against Twist Angle for a All Purpose 1⁄2 inch Diameter Glue

Stick. There should be two curves: UPLOAD TORQUE and DWLOAD TORQUE.

3. As in Part II. compute the shear strain for the angles of twist by dividing the radius of the stick

(I/4 inches) by the gage length (3 inches) and multiplying this value by the angle of twist in

radians. The angle of twist in radians is found by dividing the angle of twist by 180 and

multiplying by Pie (3.14157). For example 90 degrees is (90/180)'3.14157 or 1.57 radians.

2 This is a judgment call and uses your Engineering skills.

204
,

.

Next the shear stress is computed for each applied torque expressed in inch-pounds. This

calculation requires the experimenter to multiply the torque by the radius of the twisted sample

(_Ainches) and divide the quantity by the polar moment of inertia. The polar moment of inertia

which a property of the geometry of the twisted member is found by dividing Pie (3.14157)

times the diameter of the twisted member raised to 4th power and dividing by 64. The units are

pounds per square inch. These computations are made for each angle of twist and

accompanying torque to obtain the corresponding shear strain and shear stress. Make an XY or

Scatter Plot of this data. The values of shear strain and shear stress are to be charted by

plotting shear stress against shear strain as the independent variable to obtain the General

Purpose Glue Stick Recoverable Shear Stress-Strain Plot. Note the similarities between this

and the Plot in 2, immediately above. Check the reference line on the sample. Is it still straight?

From the shear stress-strain data the computation of work done to fail the glue stick can be

found. The best approach is to apply the trapezodial rule of integration to determine the area

under the shear stress-strain curve. On a spreadsheet this is achieved in two steps. First the

incremental work done over an angle of twist is computed, and second the increments are

summed. The units of work are inch-pounds per cubic inch of material (glue stick). This

process is to be done for both the UPLOAD TORQUE and the DWLOAD TORQUE. Make

an XY or Scatter Plot of this data that shows two curves. The difference between column

totals (total UPLOAD TORQUE work and total DWLOAD TORQUE work) is found by

subtraction and then divided by the total LOADING TORQUE work to give the portion of

energy lost to internal friction or hystersis Be sure to check UNITS for consistency.

With the Shear stress-strain data the rate of UPLOAD TORQUE and rate of DWLOAD

TORQUE can be assessed by dividing an incremental change in torsional stress by the

corresponding increment of shear strain. Make an XY or Scatter Plot of this data. There

should be two curves. If the values computed over the range of strains are constant or perhaps

oscillating about a constant value, then the applied twisting of the glue stick was done in a

'constant' fashion. Recall this was one objective for the experiment. Were you successful?

Comments:

To aid the instructor with the execution of this experiment two test made on the halves of a 10 inch

long General Purpose Glue Stick are presented,

, Figure 1 presents the data for the First Test - a test to failure. In Figures 2, 3, and 4 are shown the

LOADING, the torsional work and rate of loading curves, respectively. Shown in Figure 1 are the

following: columns 1 and 2 the twist angle in degrees recorded as 0, 90, 180, 270, 0, 90, 180, etc.

and the torsional loading load in Newtons applied at a radius of 2 inches; in columns 3 and 4 the

total angle of twist in radians and torque in inch-pounds; in columns 5 and 6 the shear stain radians

per radian and shear stress in pounds per square inch; in columns 7 and 8 incremental work and

accumulated work with units of in-lb./in^3; in column 9 the rate of loading computation with units

of in-lb./radian.

205
Angle

Degrees

0

90

180

270

360

450

540

630

720

810

900

990

1080

1170

1260

1350

1440

1530

1620

1710

1800

1890

1980

2070

2160

2250

2340

2430

Shear Torque Shear Up Shear Incrmtl Total UpRate

Force Deformatn Applied Strain Stress Work Up Work Up

Newtons Radians - in.lbs. Rad./rad. lbs./in.^2 lb in/In^3 lb in/In^3 in-lb/rad

0 0.000 0.000 0.000 0.000 0.000 0.000 0.000

3.5 1.571 1.574 0.131 128.240 8.393 8.393 1.002

7 3.142 3.147 0.262 256,480 25,180 33.573 1.002

9 4.712 4.047 0.393 329.760 38.369 71.942 0.572

10.5 6.283 4.721 0.524 384.720 46.763 118.705 0.429

12.5 7.854 5.621 0.654 458.000 55.156 173.861 0,572

13.5 9.425 6.070 0.785 494.640 62.350 236.211 0.286

I4 10.996 6.295 0.916 512.960 65.947 302.158 0.143

14.75 12.566 6.632 1.047 540.440 68.945 371.103 0.215

15.5 14.137 6.969 1.178 567.920 72.542 443.645 0.215

16 15.708 7.194 1.309 586.240 75.540 519.185 0.143

16 17.279 7.194 1.440 586.240 76.739 595.923 0.000

16.5 18.850 7.419 1.571 604.560 77.938 673.861 0.143

16.5 20.420 7.419 1.702 604.560 79.137 752.998 0.000

15.5 21.991 6.969 1.833 567.920 76.739 829.736 -0.286

14.75 23.562 6,632 1.963 540.440 72.542 902.278 -0.215

14 25.133 6.295 2.094 512.960 68.945 971.223 -0.215

15.25 26.704 6.857 2,225 558.760 70.144 1041.367 0.358

15.5 28.274 6.969 2.356 567.920 73.741 1115.108 0.072

16 29,845 7.194 2.487 586.240 75.540 1190.647 0.143

16 31.416 7.194 2.6t8 586.240 76.739 1267.386 0.000

17 32.987 7.644 2.749 622.880 79.137 1346.523 0.286

16.5 34.558 7.419 2.880 604.560 80.336 1426.859 -0.143

16 36.128 7,194 3.011 586.240 7%938 1504.796 -0.143

16 37.699 7,194 3.142 586.240 76.739 1581.535 0.000

17 39.270 7.644 3.272 622.880 79.137 1660.671 0.286

I6 40.841 7.194 3.403 586.240 79.137 1739.808 -0.286

15.5 42,412 6.969 3.534 567.920 75.540 1815.348 -0.143

Figure 1. First Test 0.5 in. Dia. Glue Stick Test to Failure Data

206
0,Sin. Dia. A|i Purpose Glue Stick Torque against Angu|ar

Deformation

10

9

8

7

._ 6

' 5

0

I-- 3-

2 2

1

0

0 10 2O 30 40 50

Angular Deformatiion - radians

Figure 2. First Test 0.5 in Dia. All Purpose Glue Stick

0.5 in. Dia. All Purpose Glue

Stick Torsional Work Against

Shear Strain

e_

<

.E

e-

-1-

#

O

"6

i--

2000.00

1800.00

1600.00

1400.00

1200.00

1000.00

800.00

600.00

400.00

2OO.00

0.00

0 2 4

Shear Strain - tad/tad

0.5 in. Dia. All Purpose Glue

Stick Rate of Loading Plot

Angular Displacement - radians

Figure 3. First Test Work Plot Figure 4. First Test Rate of Loading Plot

207
To present the computations in figure 1, a hand calculation for the 270 ° angular displacement is given:

• columns 1 and 2 contain collected raw data

® column 3 270 degrees is (270/180)'3.14157 or 4,712 radians,

• column 4 the load of 9.0 Newton is converted to a torque in inch-pounds by dividing

the applied 9.0 Newton load recorded in Newton by 4,448 Newton per pound and

multiplying by the torsion wheel radius of 2 inches in the case of the 4 inch wheel for a

torque of 4.047 in-lb.,

• column 5 the converted data of angle of twist in radians becomes 0.393 radians per radian

via 3 in, gage length divided by the radius of the glue stick (1/4 in.) and multiplied by 4.712

radians;

• column 6 the shear stress is computed from applied torque expressed in inch-pounds by

multiplying the torque 4.047 in-lb, by the radius of the twisted sample ( _Ainches) and

dMding this quantity by the polar moment of inertia which is Pi (3.14157) times the

diameter of the twisted member (1/2 in.) raised to fourth power and divided by 64. The

units are pounds per square inch,

• column 7 incremental work is (329.760+256.480 lb./sq.in.)/2*(0.393-0.262

radians/radian) = 38.369 in-lb/in^3,

• colunm 8 accumulated work is prior entry in column 8 (25.180 in-lb/in^3 ) plus 38.369 inlb/'m^3 or 71.942 in-lb/in^3,

• column 9 rate of loading via columns 4 and 3 or (4.047-3.147 in-lb)/(4.712-3.142 rad/rad)

= 0.572 in-lb/rad/rad.

The total work done is 1815.348 in-lb/in^3 while the rate of loading after 450 degrees appears to

oscillate between 0.572 and -0.572 in-lb/rad/rad.

, For the recoverable features of the glue stick the 'level-off torque in the vicinity the first values of

7,00 in-lb, as shown in Figure 2 was found. Figure 5 presents the data for the Second Test -

UPLOAD and DWLOAD of the glue stick. In Figures 6, 7, 8, and 9 the are shown UPLOAD and

DWLOAD torques, the UPLOAD and DWLOAD stresses, the UPLOAD and DWLOAD total

torsional works and rate of loading curves, respectively. Figure 5 in columns 1, 2, and 3 presents

the twist angle recorded as 0, 90, 180, 270,360, 450, etc. and the torsional loading and torsional

unloading loads while in columns 4, 5, and 6 are found the total angle of twist in radians plus

loading and unload'nag torques. Columns 7, 8, and 9 present the shear stain and shear stresses while

columns 10, 11, 12 and 13 show incremental work and accumulated work. Columns 14 and 15

present the rate of loading computation.

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To present the computations in figure 5, a hand calculation for the 270 ° angular displacement (0.393

Shr Strain) is given:

• upper columns 1 -3 are Figure 5 columns 1-3 and contain collected raw data

• column 4 270 degrees is (270/180)'3.14157 or 4.712 radians,

• column 5 the load of 10.25 Newtons is converted to a torque in inch-pounds by dividing

the applied 10.25 Newton load recorded in Newtons by 4.448 Newtons per pound and

multiplying by the torsion wheel radius of 2 inches in the case of the 4 inch wheel for a

torque of 4.609 in-lbs.,

• colt_mn 5 the load of 2.00 Newtons is converted to a torque in inch-pounds by dividing

the applied 2.00 Newton load recorded in Newtons by 4.448 Newtons per pound and

multiplying by the torsion wheel radius of 2 inches in the case of the 4 inch wheel for a

torque of 0.899 in-lbs:,

• lower column 1 is column 7 where the converted data of angle of twist in radians becomes

0.393 radians per radian via 3 in. gage length divided by the radius of the glue stick (1/4 in.)

and multiplied by 4.712 radians;

• column 8 the Up shear stress is computed from applied torque expressed in inch-pounds by

multiplying the torque 4.609 in-lb, by the radius of the twisted sample ( 1⁄4 inches) and

dividing this quantity by the polar moment of inertia which is Pi (3.14157) times the

diameter of the twisted member (1/2 in.) raised to 4th power and divided by 64. The units

are pounds per square inch,

• column 9 the Down shear stress is 73:280 lb/in.^2 following the procedure just presented,

above,

• column 10 incremental Upwork is (375.560+293.120 lb./sq, in.)/2'(0.393-0.262

radians/radian) = 43.765 in-lb/in^3,

• column 11 shows Totaled Upwork of 45.564 +43.765 in-In/in.^3, while

• columns 12 and 13 repeat columns 10 and 11 for Down work with 7.196 and 9.592

in.lbs/in.^3, respectively,

• column 14 is Up rate ofloadhng via columns 8 and 7 ( the shear stress-strain data in place

of the torque-angle of deformation data are used) is (375.560-293.120)/(0.393-0.262) for

629.795 lbs/in^2/rad/rad, and

• column 15 is the Down rate of loading for this case.

The total Up work done is 562.350 in-lb/in^3 while the total Down work recovered is 261.391 inlb/in^3, which when subtracted and divided by the total Up work and multiplied by 100 gives 53.518

percent hystersis or energy lost while in the recovery of the twisted All Purpose Glue Stick. The rate

of Up loading after 360 degrees appears below 400 lb/in^2 while the rate of loading varies in the

down load review, but generally appears to reduce when the torque is removed.

211
Appendix - Torsion Tester Parts List:

The design and construction of a torsion tester is presented. Parts to make this unit include:

1. Flex-Angle TM, of size 1 1/2 by 2 1/4 inches

A_ 4 pieces 18 inches long for uprights,

B. 8 pieces 6 inch long pieces for the cages - four for each cage,

2. Two 1⁄2 inch diameter fine thread bolts 2 V2 inches long (1/2-20UNF-2Ax21/2 HX HD Bolt) - one

for the disk via the Lazy Susan into the upper chuck and one fbr the lower moveable tail piece and

lower chuck plus seven 1⁄2 inch bolt washers to be used as spacers,

3. Two 1⁄2 inch diameter Jacobs Multi-Cratt® drill chucks,

4. Twelve 5/16 inch by 1 inch long bolts and nuts for the Flex angle and position indicator,

5. Four 4-40 round head 1/2 inch long machine screws and six washers to mount the Lazy Susan to

the upper Flex angle cage and 4 number 5 round head wood screws to fasten the beating to the

lower chipboard disc

6. One 4 inch diameter Lazy Susan beating made by EN-PAK®,

7. Two 1/2 inch thick chipboard disks each with a 1⁄2 inch diameter hole in the center and a

circumferential 'V/U shaped' groove 1/8 inch deep - one 4 inch diameter and one 8 inch diameter

are to be made,

8. Fifty feet of 50 pound test fish line,

9. A 20 Newton Ohaus® load scale to apply force,

10. Paper template for circular disk to mark 0,90,180, and 270 degrees of disk rotation and to be glue

to the upper surface of lower chipboard disk,

11. An 8 inch long flat head piece of 1/8 inch diameter wire to be bent for rotary position indicator and

mounted on the upper cage with a 7/16 bolt with nut,

12. One wood "2 x 3" x 5 1⁄2 inch long with 17/32 inch diameter through hole in the center of the 3 x

5 1⁄2 inch face,

13. One 10 in by 30 in by 1 inch mounting board, and

14. Two carrying handles (protruding window handle style.) plus 8 number 5 by 1⁄2 inch long

mounting screws,

15. A 'U' Bolt to be made from a 13 inch long 1⁄4 inch diameter threaded rod bent to have two 90

degree 4 inch long legs to place into the tester below the lower grip/cross-head to prevent the head

from falling,

16. Four 7/16 one inch long machine screws with washers and nuts to fasten the tester via the lower

cage to the mounting board.

17. A small c-damp can be used to block rotation of the torsion wheel when placed on the disk that

extends past the upper cage.

212
Appendix - View of the Torsion Tester:

Note the pointer to the top left of the lower wheel, the upper and lower cages, the moveable cross

head, the 'U' bolt just below the cross head, and the Jacobs chuck key used to tighten the chuck jaws

onto the glue stick.

Figure IA. Picture of Torsion Tester

Appendix - Assembly:

Obtain the parts. Assemble the upper and lower cages with one bolt in the comers of the narrow

surface. Check that the pieces form a square. Join the four 18 inch pieces on the wide dimension with

one and one-half inches overlap and fasten each unit of two pieces with one bolt in each end to cages.

Fasten the lower wooden block via the V2bolt, a washer, the block, a washer and the chuck. Make the

disks. Mount the paper template on the top surface of the large disk. The upper bolt passes a washer,

two disks, three washers into the upper chuck. To the upper cage fasten the lazy Susan beating via the

4 small screws and washers. Prior to this the lazy Susan bearing is fastened to the lower disk with the

four wood screws. Be sure the alignment is good. Mount the position pointer on the top cage. Wind

the fish line around the upper disk groove - if the line is long friction will hold the line. Otherwise, drill

two 1/8 inch diameter holes 3/8 inches apart near the edge groove and make a cut across the edge

groove from one hole to the groove in the disk and tie the line down. Center the lower cage on the

mounting board_ Then mark and drill four holes in the mounting board aligned with the centers of the

four sides of the lower cage. Countersink the hole from the bottom board surface and place the flat

head machine screws into the board and add washers and bolts inside the cage.

Acknowledgments:

The author is appreciative of the assistance provided by Mrs. Karplus throughout the construction,

assessment and conduction of early test with the torsional test apparatus.

213
214
MAKING THE JUMP FROM ROTE LEARNING

TO APPLICATION IN 50 MINUTES

Donna C. S. Summers

University of Dayton

Industrial EngineePmg Technology

300 College Park Drive

Dayton, Ohio 45469-0249

Telephone: 937-229-2974

e-mail dsummers @engr.udayton.edu

215
Biography:

Dr. Donna C.S. Summers teaches innthe Industrial Engineering Technology program m

the University of Dayton. She earned her Ph.D. at the University of Cincinnati, where

her major areas of study included Quality Assurance and Human Factors. Dr. Summers

consulting work has focused on problem-solving through the application of quality

assurance techniques. Her text, _, contains numerous case studies based on her

consulting work.

216
Making the Jump From Rote Learning

to Application in 50 Minutes

Donna Summers, Ph.D.

Industrial Engineering Technology

University of Dayton

Abstract:

In a traditional Statistical Process Control (SPC) course experimentation is limited due to

the fifty minute time span of a typical structured course. Still, students need to gain

knowledge of the practical application of the SPC tools in a business setting. End-ofchapter problems rarely provide insights into the complexities of solving an actual

industrial dilemma. Without this knowledge, how will students learn which tools and

techniques to apply to what situations? This presentation discusses the use of case

studies in a traditional fifty minute class in order to help students make the leap from rote

learning to application of techniques.

Key Words:

Case study, statistical process control, data gathering, technique selection, technique

application, data interpretation.

Prerequisite Knowledge:

An understanding of computers and familiarity with installing commercial software on

PC's. A basic understanding of probability and statistics.

Objectives:

To use Case Studies to:

-create an understanding of the complexities of problem-solving in a business

setting.

-encourage the use of statistical data when making decisions.

-enhance student's understanding of the importance of interpreting statistical data

when making decisions.

Equipment and Materials:

A case study.

Visual aids associated with the case (parts, drawings, products, etc.).

Access to computers and statistical process control software.

217
Introduction:

Case studies based on real-life situations provide students with an understanding of the

knowledge and effort necessary to solve business problems. In a traditional Statistical

Process Control class, students are exposed to the techniques associated with problemsolving through lectures and related end-of-chapter problems. Though this provides

students with a working knowledge of SPC tools and techniques, it does not necessarily

prepare them with the knowledge necessary to know when to apply what techniques

when a particular situation arises on-the-job. This lack of applications knowledge may

lead to a more shoot-from-the-hip, feelings-styled approach to problem-solving, rather

than an organized approach involving analyzing data related to the problem.

The use of case studies in a traditional classroom brings students insight into the

complexities of real-world quality assurance.

Procedure:

Preparing a Case

Case studies enhance students' understanding of the complexities of problem-solving in

an business setting. The key to the successful application of cases in a SPC course is the

availability of abundant real data. Cases can come from a variety of sources including

past consulting experiences or any day-to-day product or service that is experiencing

difficulties. The writer of the case must have access to industrial data or the ability to

generate such data. Cases are difficult to construct using artificially generated data. And

unlike real data, artificial data, doesn't give the student insight into the complexities of

real-world problem-solving. Instead, the tidy answers artificial data create may inhibit

student learning by causing them to assume an answer is always readily available. Real

data is slippery and must be analyzed to determine what it is trying to tell us. This

analysis is what generates student learning and underscores the importance of interpreting

statistical information when making decisions.

Several cases should be used throughout the term. They should cover a wide variety of

industries including manufacturing, chemical processing, electronics, computers,

packaging, hospitals and other service industries, as well as government applications like

the Post Office or the IRS. The cases should require the gathering, analysis and

interpretation of data, as well as background information related to the problem. This

ensures that the students learn that quality assurance issues do not magically appear,

instead, they are caused by the decisions made by those associated with the manufacture

of a particular product or the provision of a service. Some of the cases used should be

open-ended, others should have a more narrow focus with specific answers. This will

encourage the student to think about the complexities of life in business.

Because problem-solving in industry requires the application of a variety of techniques,

many cases may merge information and techniques from several chapters. For example,

in a study related to a bracket creating difficulties during an assembly process, the case

218
may use flow charts to describe the assembly process, Pareto diagrams to determine the

most likely area to investigate, a cause-and-effect diagram to isolate the potential causes,

and histograms or control charts to analyze data related the bracket hole alignment that

has been identified as the root cause of the problem.

Another challenge facing the writers and users of case studies is the need to convert

information and data associated with a real-world problem into a usable structure for

learning. Ease this process by focusing on formulating the case around proposed class

discussions of crucial formulas or ideas. Provide sufficient background information to

enable the students to understand the problem at its inception. As the case develops,

additional information can lead the student through the problem-solving process.

Using Cases in the Classroom

Case studies encourage the use of statistical data in decision-making. Users of case

studies need to be aware of several aspects concerning cases that are critical when using

them in a classroom setting.

Most importantly, cases should be well integrated with the material covered in the

chapter. For SPC, the focus of these cases should be on the analysis and use of quality

assurance techniques when solving complex problems.

Case studies are used most effectively when the students work on the cases in parallel

with class discussions of pertinent material. Due to their complex nature, work on case

studies often extends from one class to another, just like problem analysis in business

extends over a several day period of time. If the case is structured to mimic a business

environment, then the information presented in the case, as well as the solution to the

case will extend over several class periods. This approach enhances student learning

because it gives them time to absorb the information in class, apply relevant classroom

information to the case, and discuss the evolving results in class. This parallel problemsolving, question and answer format brings the material to life and creates a necessity for

understanding the material as it is presented, not just immediately before the exam for use

in solving simpler problems.

The use of computers and commercial software will enable the students to analyze and

interpret realistic charts created with a significant amount of data. This is crucial in order

to add depth and complexity to the problem-solving experience. The use of computers

also enables students to complete the problem-solving exercises without becoming

bogged down in calculations. For the customary SPC class, software which creates

histograms, Pareto diagrams, X-bar, R, p, u, and c charts should be sufficient for most

case studies.

Comments:

The use of cases in a fifty minute class enlivens lectures by adding discussion elements

concerning real world products and services. Using cases in conjunction with traditional

219
lectures and homework problems requires time for in-class discussion of the cases. Class

discussion of material should reference the case in order to make it an integral part of the

course rather than just another assignment. On the surface, it may appear that allocating

time for in-class discussion of the case detracts from needed lecture time. On the

contrary, discussions focused on the cases tend to encourage student learning and

generates an answer to "why do we have to know this?" An enhanced understanding of

the applicability of the information increases student interest in the material thus

improving the accumulation and retention of information.

References:

Summers, D. Quality, 2 nd ed., Prentice Hall: Upper Saddle River, NJ (2000).

TQT Handbook, PQ Systems, Dayton, Ohio (1996)

220
DEVELOPMENT OF COMPOSITE MATERIALS

MANUFACTURING AND EXPERIMENTAL

EVALUATION FACILITIES FOR

UNDERGRADUATE ENGINEERING STUDENTS

Ronald B. BucineH

Union College

Department of Mechanical Engineering

Schenectady, New York 12308

518-388-6023

bucinelr@union.edu

221
Ronald B. Bucinell i

222
Development of Composite Materials Manufacturing and Experimental

Evaluation Facilities for Undergraduate Engineering Students

Ronald B. BucineU, Ph.D., P.E.

Union College

Department of Mechanical Engineering

Schenectady, NY 12308

National Educator's Workshop - 2000

October 29, 2000 - November 1, 2000

In the last quarter of the 20 th century, the use of advanced composite materials grew

rapidly in aerospace, hydrospace, infrastructure, automotive, and sporting goods markets. The

macroscopically heterogeneous and anisotropic nature of these materials complicates their

behavior and performance. Courses covering composite material behavior and design have

traditionally been offered as electives in the senior year or more commonly in graduate programs.

As a result few engineering students that are graduating with bachelor degrees in engineering are

able to optimize the performance of composite materials through design.

With the help of the National Science Foundations ILI program, Union College has

developed manufacturing and experimental evaluation laboratories dedicated to introducing

composite materials to undergraduate students. Undergraduate students at Union College now

encounter composite materials as early as their sophomore year in their material science and

mechanics of materials courses. In the junior and senior years, students can take introductory

courses to composite materials and composite material manufacturing. These facilities are also

made available to students for their senior capstone project.

It is not practical to infer that a graduate level understanding of composite behavior can

be provided to undergraduate students. It is reasonable to provide undergraduates exposure to

the unique behavior of composite material and give them an introduction to these materials that

will aid them in the design of structures that utilize this class of materials.

223
Biographical Summary For

Ronald B. Bucinell, Ph.D., P.E.

Dr. Bucinell is an Assistant Professor of Mechanical Engineering at Union College.

Since joining Union College in September of 1993, he has taught courses and laboratories in

engineering mechanics and design. His other responsibilities include undergraduate academic

advising, senior design project supervision, undergraduate research supervision, and graduate

research supervision. Dr. Bucinell is currently advisor to the International Virtual Design Studio

project that is currently being conducted in conjunction with the Middle East Technical

University in Ankara, Turkey and ESIGELEC in Rouen, France. He is working to expand this

program to several other international universities and corporations. Dr. Bucinell is also advisor

to the Mini-Baja and Formula SAE racing teams at Union College. He has taken a leadership

role in developing undergraduate laboratories, the new undergraduate curriculum, and revisions

to the graduate program for the Mechanical Engineering Department at Union College. He is the

director of the engineering mechanics and composite materials manufacturing laboratories at

Union College.

Dr. Bucinell's research areas include mechanics of composite structures, test method

development, and design. He has been awarded NASA Summer Fellowships in 1994, 1995,

1996, and 1997. He currently is working on grants from NASA, the U.S. Navy, U.S. Airforce,

and U.S. Army. He is also working with several small businesses to develop their composite

materials technology. Dr. Bucinell is also working with the New York State Department of

Transportation on introducing composite materials into the infrastructure of New York State.

Prior to joining Union College, Dr. Bucinell was employed by Materials Sciences

Corporation in Philadelphia, Pennsylvania as a research engineer for four years. His

responsibilities included the development of thermal-mechanical models to predict the response

of composite materials and structures, test method development, and material processing models.

Prior to this Dr. Bucinell was employed by Hercules Aerospace Corporation in Salt Lake City,

UT, for three years. While at Hercules he was actively engaged in research activities that focused

on the application of advanced materials to rocket motors. Some of the rocket motor programs

that Dr. Bucinell has participated on include Titan IV, Delta II, SRAM, Small ICBM, Trident,

Peace Keeper (MX), Space Shuttle Solid Rocket Motors, and many others. Dr. Bucinell was also

employed by Boeing Aerospace in Seattle, Washington and the Dyna East Corporation in

Philadelphia, PA. In 1990 Dr. Bucinell co-founded the company Innotech (518/783-0800) that

provides a variety of engineering design and analysis services to corporate and government

clients.

Dr. Bucinell holds the degrees of B.S. in Mechanical Engineering from the Rochester

Institute of Technology; M.S. in Mechanical Engineering and Applied Mechanics from Drexel

University; and a Ph.D. from Drexel University. From 1987 to 1990, he held the position of

Adjunct Assistant Professor of Mechanical Engineering at the University of Utah and from 1992

224
to 1994 held the position of Adjunct Assistant professor of Mechanical Engineering at Temple

University.

Dr. Bucinell is a licensed Professional Engineer in the State of New York. He is currently

a member of the American Society of Mechanical Engineers (ASME), American Society for

Testing and Materials (ASTM), Society for Experimental Mechanics (SEM), American Society

for Engineering Education, and Sigma Xi (Honorary Research Society). He is the Co-Editor of

the Journal of Composite Technology and Research. He is chairman of the ASTM D30 Ring and

Filament Wound Test Methods Task Group (D30.04.05) and Chairman of the ASTM D30

Research and Mechanics Subcommittee (D30.02). Dr. Bucinell was the chairman of the ASTM

VII Symposium on Fatigue and Fracture to be held in St. Louis on 5-8 May 1997. Dr. Bucinell is

listed in Marquis Who's Who in Engineering, Marquis Who's Who in Finance and Industry, and

in Marquis Who's Who in the World. He has authored many papers in the field of composite

materials, has presented his work at technical symposia, and has been invited to speak at several

government installations.

Dr. Bucinell's civic activities include the introduction of a NSF/Smithsonian hands-onscience program to the Elmer Avenue Elementary School, in Schenectady, NY, in the 1st and

3rd grade during the 1994-95 school year. This program was so successful that in 1995 a Goals

2000 grant was awarded to the Schenectady School District to introduce this hands-on science

program in grades 1 through 4 in five of the Schenectady elementary schools. Additionally in

1995, Dr. Bucinell was awarded a grant from Sigma Xi to pilot a hands-on science program in

the 5th grade of the Elmer Avenue Elementary School. Dr. Bucinell is a member of the local

school district Parent Teacher Organization and has served as a member of the Local School

Shared Decision Making Team. He has also served on school district committees to bring

technology into k-12 education. He is also a Cub Scout den leader and Boy Scout advancement

chairman. He is currently a Boy Scout merit badge counselor for space exploration, engineering,

scholarship, drafting, astronomy, climbing, and personal fittness. He also coaches little league

baseball, youth hockey, and youth football.

225
226
NANOTECHNOLOGY EDUCATION:

EXPLORING A COMPACT DISK STAMPER

B. L. Ramakrishna

Center for Solid State Science and

Department of Plant Biology

Arizona State University

Tempe, Arizona 85287-1704

e-mail bramakrishna@ asu.edu

Eddie W. Ong

and

Andrew Chizmeshya

Center for Solid State Science

Arizona State University

Tempe, Arizona 85287-1704

Telephone: 480-965-6560

Jeremy Rowe

Information Technology

Arizona State University

Tempe, Arizona 85287-0101

227
Biography:

B.L. Ramakrishna is an Associate Professor in the department of Plant Biology and

Director of Education and Outreach programs in the Center for Solid State Science. He

received his Ph.D. from Indian Institute of Technology, Madras, India. His research

interest is in the area ofnanoscale studies of Biomineralization, where problems lie at the

crossroads of Biology and Materials Science. He is committed to the integration of

research frontiers into the undergraduate curriculum.

Eddie W. Ong is a research scientist at the Center for Solid State Science currently

working on the 1N-VSEE project and manages the multi-user Scanning Probe

Microscopy (SPM) Facility at Arizona State University (ASU). He received his Ph.D. in

Solid State/Inorganic Chemistry from ASU. He then worked as a Postdoctoral Fellow at

Los Alamos National Laboratory and has also taught at Northern New Mexico

Community College and Maricopa Community Colleges in Arizona. He is experienced in

the use of multiple techniques for the characterization of materials and is involved with

the development of S PM over the Internet as an education and outreach resource for high

school and undergraduate students.

Jecemy Rowe serves as an academic professional for Information Technology at Arizona

State University. He received his Doctorate in Educational Leadership and Policy Studies

and Masters in Educational Technology and Audiovisual Education from Arizona State

University. He has been involved in planning for preservation of non-print media and in

policy issues related to copyright, licensing, and ownership of multimedia materials.

Andrew Chizmeshya is a condensed matter physicist in the Center for Solid State Science

at Arizona State University (ASU), and the director of the Goldwater Materials

Visualization Facility. He received his Ph.D. Condensed Matter Theory from Queen's

University at Kingston, Canada. Dr. Chizmeshya is involved in the development of K-12

science education materials, including the implementation, testing and deployment of

remote access educational resources.

B. L. Ramakrishna

228
Nanotechnology Education: Exploring a Compact Disk Stamper

B.L. Ram_shna 1' 2, Eddie W. Ong 1, Jeremy Rowe 3 and Andrew Chizmeshya 1

ICenter for Solid State Science, Arizona State University, Tempe, AZ 85287-1704

2Department of Plant Biology, Arizona State University, Tempe, AZ 85287-1601

3Information Technology, Arizona State University, Tempe, AZ 85287-0101

Abstract:

The integration ofnano-science and technology concepts into the curricula of

upper-division high school and lower-division college levels, requires innovative

educational approaches that will help students understand the structures at the nanoscale

and its correlation to the properties of matter at the macro-, micro- and nanoscale.

Important vehicles for training these students include the integration of analytical

instrumentation with materials education, and employment of advanced

telecommunication technology to deliver an interactive and discovery-based educational

experience.

The Interactive Nano-Visualization for Science and Engineering Education (INVSEE, http://invsee.asu.edu) project has created a consortium of university and industry

researchers, community college and high school faculty and museum educators, led by

Arizona State University (ASU), with a common vision of building an interactive World

Wide Web (W-WW) site to develop a new educational thrust. This NSF-funded project

has developed a remotely operable scanning probe microscope (SPM), a visualization

gallery of images, and a number of educational modules designed around materials

themes.

The important goals of the IN-VSEE project are to (1) educate students in the

principles, execution, interpretation, and rational design of experiments.; (2) increase

student understanding of structure, composition, and properties of materials across size

scales with examples that cut across traditional disciplinary barriers and (3) to prepare the

future workforce for the upcoming nanotechnology revolution.

This paper describes investigations of a CD stamper to demonstrate how of

investigating a material by multiple techniques can give a comprehensive and selfconsistent knowledge of its structure and composition at the macro-, micro- and the nanoscale. The choice of the familiar CD brings relevance to materials science and

engineering education content. The ability to access sophisticated instrumentation

remotely via the Intemet facilitates the building of a "laboratory without walls" and

brings a new meaning to hands-on experience

The use of multiple analytical instruments such as Optical Microscopy, Scanning

Electron Microscopy (SEM), SPM, Energy Dispersive X-Ray Spectroscopy (EDX),

Auger Electron Spectroscopy (AES) and Rutherford Backscattering (RBS) in

understanding the structural and materials aspects of a compact disk stamper will be

illustrated. Remote experimentation over the World Wide Web using Scanning Probe

Microscopy (SPM) and Rutherford Backscattering (RBS) will be demonstrated.

229
Key Words: IN-VSEE, Interactive Nano-Visualization for Science and Engineering

Education, nanoscience, nano-engineering, nanotechnology, Compact Disk, remote

experimentation, Scanning Probe Microscopy (SPM), Scanning Electron Microscopy

(SEM), Optical Microscopy, X-ray diffraction, Energy Dispersive X-Ray Spectroscopy

(EDX), and Rutherford Backscattering (RBS).

230
Prerequisite Knowledge:

Introductory information on the size and scale of various objects and the use of

microscopy to explore these objects can be found on an IN-VSEE module "Size and

Scale" at

h__.ttp://invsee.asu.edu/nmodules/sizescalemod/

Information about the operating principles of a Scanning Probe Microscope can be found

on an IN-VSEE module "Theory and Simulation of SPM" at

://invsee.asu_.edu/mnodules/spmm_od/

Information on the formatting and manufacturing of optical storage media can be found

on an IN-VSEE module "Information Storage Media - the Information Age is Here" at

http://invsee.asu.edu/mnodules/isrmnod/

Summary information on the working principles, advantages, and limitations of a number

of analytical instrumentation are illustrated in the schematics shown in Figure B.

Additional information can be found on Charles Evans & Associate's web site on the

following pages

Working principles: http://www.cea.corn/whatis.htm

Technical limits: http://www.cea.com/table.htm

Objectives:

Determine the physical dimensions of the data bits.

Determine the chemical composition of the sample.

Relate the data capacity of the CD to the dimensions of the data.

Relate the optical properties for e.g. Iridescence of the CD to the feature sizes.

Relate the measurements at the micro and the nano scale to the physics of the CD.

Equipment and Materials:

Instrumentation

Analytical instruments expand, beyond the capabilities of the human senses, our

knowledge of materials systems. The equipment below was used for explonng the

compositional and topographical nature of the CD stamper. In this paper we are

illustrating the utility of these various techniques and how they can be used to get a

comprehensive examination of the sample. However, if some or all of these facilities are

not available close at hand, one could utilize experimental resources around the country

to obtain data on samples. It is possible to obtain the data from various image galleries

over the web such as from e.g. http://invsee.asu.edu. It is also possible to access some of

these sophisticated instruments via the Intemet.

I Analytical Technique

Optical Microscopy

Scanning Probe Microscopy (SPM)

Scanning Electron Microscope and (SEM)

Instrumentation / Model

Digital Instruments Nanoscope III TM AFM

Thermomicroscopes Explorer TM AFM

JEOL JSM-840

231
Energy Dispersive X-Ray Spectroscopy Same as above

(EDX)

Rutherford Backscattering (RBS)

Auger Electron Spectroscopy (AES)

Built in-house, Ibeam Facility

Physical Electronics SAM 590

Information on the technical specifications and capabilities of the instruments at ASU

that was used for this study can be found at:

http://gmsl.eas.asu.edu/gmvf

IN-VSEE's Remote SPM instrument can be accessed through the IN-VSEE web site at:

http://invsee.asu.edu

under the heading of"SPM Live!"

Figure A. Spatial resolution and relative sensitivity of some commonly used analytical instruments.

The picture above (Figure A) schematically shows the spatial resolutions and sensitivities

of a number of analytical instruments, which measure topography, optical properties,

chemical composition, electronic structure, etc. Summaries about the operating

principles of several surface analytical techniques can be found in a reference by

Somarjai [ 1]. Schematics showing illustrating the operating principles of advanced

surface analytical instrumentation for chemical analyses is shown in Figure B below.

232
Figure B. The operating principles of some of the advanced analytical techniques used to determine the

chemical composition of the CD stamper surface: (a) EDX, (b) AES, (c) RBS, and (d) PIXE. The

elements that the techniques can detect and the surface penetration depths are shown. (Adapted from

reference 2).

Material

Compact Disk (CD/DVD) and Compact Disk stamper samples can be procured from:

Maxwell Production, LLC

8521 E. Princess Drive, Scottsdale AZ 85255

telephone: (480) 609-9555.

Introduction:

Compact Disks

Optical media systems read the differences in laser light reflected from a series of holes

or pits on the surface to represent the 0s and ls of binary data. The use of phase shifts to

detect minor changes in material surface is based on a technique developed in 1934 by

Nobel Prize winner F. Zemike.

The first popular use of optical storage began in the 1970's with release of the Pioneer®

video laser disk. The disks were about 30 cm in diameter. Despite slow public acceptance

of the videodisk, soon the 13 cm audio CD-ROM was released. The audio CD was

accepted almost immediately and soon replaced the LP record as the most popular media

for distribution of music. The use of CD-ROM for data storage followed soon after.

CD-ROM store data in patterns of small pits arranged in over many thousands of tracks

across the surface of the disk. CD-ROM drives use a laser from below the disk to read

the data from the disk. The presence of a passing pit, or space, effects the reflection of the

laser from the surface of the CD-ROM. The changes are captured by the lens, converted

into electrical signals and translated into data. The data can represent audio, video or

computer readable files.

233
The natural curiosity, familiarity with CDs, as well as the richness of experimental tools

that can be brought to bear makes a Compact Disk stamper sample an excellent candidate

for experimental exploration. The investigation of a CD sample provides a valuable and

attractive means to illustrate some basic principles of physics. It allows one to bring to

the fore some of the materials and engineering issues. The Common questions asked by

students include:

What causes the rainbow effect of light shining on a CD or CD stamper?

What kinds of materials are used to make CD and its stamper master and what criteria

determined the choice of material?

How does the surface of a CD stamper look topographically and chemically?

How big are the data bits on a CD? Are all of the data bits the same size?

How can we estimate how much data can be stored on a CD?

How is the data read?

How do the size of the data bits and track separation relate to the wavelength of the laser

used for reading the data on a CD?

Procedure:

Sample preparation

Obtain a CD stamper sample and cut out several (5-6) pieces that are roughly 1cm X 1cm

using a scissors or a pair of tin snippers. Avoid leaving fmgerprints on the shiny surface

of the sample with your hand. Place the samples in a beaker containing acetone and

place in a sonicator to clean any dust, grease and other contaminants for 10 seconds.

Repeat the sonication with trichloroethylene (TCE) in the beaker in place of the acetone

for another 10 seconds. Pour out the solvent and allow the samples to dry for 4-5 hours.

Consult your instrument operator for instructions on mounting the sample and running

the instrument.

Results:

The CD stamper sample was investigated by several techniques that allows one to get a

comprehensive picture at the macro-, micro- to the nano- scale. In the following

paragraphs the results from the various tools are described. The sample was first

inspected visually with our eyes and then with a photographic camera. Then the optical

microscope was employed to observe features that were not visible to the human eye but

this yields only 2-D information. To extend our sense of touch, a SPM was used to "feel"

the surface to determine the 3-dimensional aspects of the features. A SEM in combination

with EDX was then used to get information about the chemical composition. More

ref'med compositional analysis was accomplished with AES which provides information

about lighter elements as well as depth profiling. RBS and PIXE were employed to

determine whether the elements exist in more than one compound on the surface.

A macroscopic visual inspection of a CD or a CD stamper shows a shiny reflective disk.

A typical view of a CD is shown in Figure C. The samples display a rainbow-color

reflection of light when the object is tilted at different angles relative to the eye. What is

234
causingthisplay of the color? Is this due to the chemical or structural characteristics of

the object's surface?

Figure C. Macroscopic image of a CD obtained with a digital camera shows the rainbow of colors on the

CD surface, seen above as different shades of gray.

Optical Microscopy

Closer inspection with an optical microscope, utilizing the interaction of visible light with

the surface is illustrated by the image of the CD stamper shown below in Figure D.

There are topographical features on the surface of uniform width and in 3 different

lengths. There arranged into lines, known as tracks, separated from each other at a

uniform spacing. What is the topographical nature of these features? Are they flat,

depressions, or protrusions on the surface? Non-uniformity in the color of the surface is

observed. What is causing these different colors? Are these regions of corrosion? Are

these due to thin coating of contaminants on the surface?

Figure D. 30gin x 30gin area of CD stamper surface observed by optical microscope. The non-uniform

colors may be due to surface contaminants or corrosion.

SPM

A three-dimensional examination of a CD or CD stamper surface by a scanning probe

microscope, utilizing a very probe, shows that the features on the surface are not flat

235
(Figure E). The image obtained from this instrument is shown below where the height of

the feature is color-coded, lightest color is highest. On a CD these features, known as

steps, are depressions while on a CD stamper these features are protrusions. The height

of the protrusions is about 200 nm. The width of these features is around 0.75_m. The

lengths measure about l[xrn, 2 _trn, and 3 [xrn for the short, medium, and long features,

respectively. A distance of 1.5 track from the next.

Figure E. 30 [am x 30 _rn scan of CD stamper surface by SPM to obtain 3-D topographic information. The

brighter areas are higher off the surface.

SEM and EDX

The CD stamper was further examined using a scanning electron microscope. The

images obtained showed similar features to those found by SPM. The dimensions of the

surface features as measured by SEM agree with those reported by the SPM. However,

height information cannot be obtained from the SEM data. This instrument, when fitted

with an EDX capability, has the advantage of being able to pinpoint a location on the

surface and obtain information about the chemical composition of the sample there.

Figure F shows the SEM image of the CD stamper surface. Areas that hold a higher

charge are brighter in color.

Figure F. A 30 pxn x 30 ktm scan area of the CD stamper imaged by SEM.

236
Several locations on the surface of the CD stamper were probed by the EDX attachment

of the SEM to determine the stamper's chemical composition. A typical EDX spectrum

of the surface is shown below (Figure G). This spectroscopy showed that the stamper

was made from nickel. Is this sample made entirely from nickel? From this analysis we

know that no other elements with an atomic number higher than sodium is present,

besides nickel. However, we can neither confirm nor deny the presence of elements

lighter than sodium on the surface because of detector limitations of our instrument.

600i:

0

(.,.)

Ni

Energy (keY)

Figure G. A typical EDX spectrum of the CD stamper surface. It is composed mostly of nickel.

AES

A survey of the CD stamper surface with Auger electron spectroscopy, after the

SEM/EDX experiments were performed, revealed the presence of carbon, oxygen, and

traces of nitrogen besides nickel. An AES spectrum of surface is shown below (Figure

H). Does this composition represent the chemical makeup of the object?

.A.u_m_,rL_lectren Sl_ec_,scop_, of CD Stmuper Snrfnce

iNi 0 Ni

aN(E)

100 200 300 400 500 600 700 800 900 i000.

Kinetic E_' (eV)

Figure H. An AES spectrum of the CD stamper surface showing the presence of nickel, carbon, oxygen

and nitrogen.

237
The penetration depth of the AES analysis is rather shallow. Since our AES instrument is

outfitted with an ion gun that can dig through the sample surface with argon ions at 20

nm/min, we performed a compositional depth profile. The elemental composition

changed with the depth from the surface. Figure I below shows the atom percent of each

element as a function of depth.

O

Figure I. AES depth profiling of the CD stamper shows a change of composition with depth from the

surface.

Carbon and nickel dominate the surface. The negligible amounts of oxygen present

suggests that very little of the nickel is in the form of oxides. The large quantity of

carbon on the surface may be an organic contaminant or polymer there. The interior of

the CD stamper is composed of nickel.

RBS and PIXE

Rutherford Backscattering analyses was performed on the surface of the CD stamper to

determine if the chemical elements present exist in more than one form (i.e., contained in

different compounds. Helium ions of several energies were used to study the depth

dependence of the elements. Nickel was found to exist predominantly as metallic nickel.

Carbon was also detected and found to decrease with depth from the surface, supporting

the AES depth profiling results. Particle Induced X-ray Emission spectroscopy found

traces of iron along with the metallic nickel. These findings are shown by Figures J and

K, respectively.

238
200i RBS Spectrum of CD Stamper

;,.,.=

_100-

Z

50"

1.0 1.5 2.0 2,5 3,0 3.5

E_rgy (MCV)

Figure J. An RBS spectrum of the CD stamper surface showing a single species of nickel and the presence

of carbon. The intensity of the carbon peak decreased with depth.

i

Fe li i

II lttlb, ,ili,tlll,, .,,

i I

Figure K. PIXE spectrum of CD stamper surface shows the presence of nickel and traces of iron. The

other techniques did not find the presence of iron.

X-ray Diffraction

The analytical techniques discussed above do not tell us if the nickel exists in a

crystalline or amorphous form and how the grains of nickel composing the CD stamper

are oriented. X-ray Diffraction experiments, using X-ray radiation produced by a copper

anode (Cu Ko_; wavelength = 1.5418 Angstroms), were performed to answer these

questions. The resultant diffraction pattern, shown in Figure L, is consistent with the

material being crystalline metallic nickel with its atoms arranged within a face-centered

cubic unit cell with sides measuring 0.3524 nm (3.524 Angstroms). This pattern,

however, does not match the ideal X-ray "fingerprint" of a metallic nickel sample that

has its grains randomly oriented. Instead it shows that the crystalline grains of nickel

were preferentially oriented with its (100) crystalline axis perpendicular to the CD

stamper surface as evidenced by the intense (200) diffraction peak. If etched, the surface

may exhibit a large number of crystalline grains with right-angled boundaries. The

239
growth behavior of the nickel grains may have been affected by the methods used to

fabricate the CD stamper.

100-

75-

50-

25-

X-ray Pewder Diffraction

of

Compact Disk Stamper

(111)

(200) d= 1,7634A

(220)

d= 1,748A

°"T l

X10*3_1 Ideal Int en_ityDistribution for t _4-_,_

l Nickel crystals_4th random |

2- II_teta(de_e_ )

Figure L. X-ray diffraction pattern of CD stamper surface shows that a large number of nickel crystalline

grains are preferentially oriented with their (100) crystalline axis perpendicular to the surface.

Discussion:

The data is recorded on the CD, after being pressed against a CD stamper, as steps

arranged along a track spiraling out from the center of the disk. In the presence of a step,

light reflected from its top will destructively interfere with light reflected from the area

surrounding the step. Where a step is absent no such destructive interference occurs.

Thus the intensity of the received light signal varies as the steps pass under the laser

beam. The lengths of the steps and of the gaps between them transmit a code as a series

of 1 's and O's. The steps on the recording track used to carry the music code are 0.5 gm

wide. The length and spacing along the track of the steps is used to encode the signal,

with a minimum step length of about 1_trn. If a beam of light with a radius of 1 pzn were

centered on a long step, it would reflect about half of the incident light.

The 'pitch' of the track is only about 1.5 grn (as compared with the 100 gm for an LP

record), which means that the CD can act as a reflection diffraction grating with a

micrometer-sized grating constant. Application of some basic principles of physics will

let us recognize that the CD can act like an optically periodic structure or grating. An

experiment using a CD for white light diffraction is described by Cornwall [3].

240
The small size of the data is responsible for another identifying characteristic of the CDROM. The pits are close in size to the wavelengths of visible light. The interference of

the light with the pits diffracts the light, creating the familiar "rainbow" pattern on the

surface of the CD-ROM. The pits are approximately 1/4 the wavelength, or 0.5 grn high.

The dimensions of the data pit give rise to the iridescence of a compact disk.

The physical dimensions of the data steps on the CD stamper is constrained by how light

interacts within the material of the CD being fabricated. Unlike an LP record, the data

track on a CD is 1.2 mm beneath the surface of the disk. The material of the disk,

typically a polycarbonate plastic, has a refractive index of 1.55. Laser light with a

wavelength of 780 nm in air changesto 503 nm in the plastic material of the CD [4]. The

radius of the converging cone of light is 1.05 grn [4]. It is this dimension that dictates the

minimum separation of the recorded tracks. Adjacent tracks set 1.6 gm apart puts one

track beyond the reach of a beam scanning another neighboring track. Destructive

interference occurs if the path difference between a ray reflected from a step and one

reflected from the surrounding background surface is half a wavelength. Since the

wavelength of the light within the CD is 503 nm, a path difference of about 250 nm is

required. The half-wavelength path difference is achieved in the outward and return

journey of the two rays by a step of height 125 nm.

Data CD-ROMs can have as many as 22,000 tracks and can store up to 650 megabytes of

data or 75 minutes of audio information. An aluminum gallium arsenide diode laser

giving light of wavelength 780 um is commonly used. The recent development of a blue

light laser has implications for the future design of compact and optical disk systems. A

shorter wavelength that would be used to read the data from the disk would permit the

use of narrower and more densely packed recorded tracks. This would result in larger

data storage capacity or longer playing times allowable on future CDs.

Conclusion:

This experiment on the CD stamper demonstrates the necessity of investigating a material

by multiple techniques so that one can get a comprehensive and self-consistent

knowledge of its structure and composition at the macro-, micro- and the nano- scale. The

choice of the familiar CD as an illustrative sample is powerful in delivering science and

engineering education content to learners by connecting with their everyday experience.

The ability to access sophisticated instrumentation remotely via the Internet facilitates

the building of a "laboratory without walls" and brings a new meaning to hands-on

experience.

References:

. Gabor A. Samorjai, Introduction to surface chemistry and catalysis, John Wiley

and Sons, Inc., New York, 1994. pp. 15-35

241
.

0

°

L.C.Feldman and J.W. Mayer, Fundamentals of Surface and Thin Film Analysis,

North-Holland, New York (1986).

John A. Cope, "The Physics of the Compact Disc", Physics Education, 28, 15-21

(1993).

Malcolm G. Cornwall, "CD Means Colourful Diffraction", Physics Education 28,

12-14 (1993).

Commems:

A discovery-based lesson in determining the data capacity of a compact disk using

images obtained from scanning probe microscopy images and other information can be

found at:

http ://invsee.eas.asu.edu/Modules/size&scale/unit 7 /unit 7.htm#tea

Acknowledgement:

The authors would like to thank Timothy Karcher for performing the AES experiments,

Barry Wilkens for performing the RBS/PIXE experiments and Dr. Thomas Groy for

performing the x-ray diffraction experiments at ASU. We also thank the Goldwater

Materials Science Laboratories and the Multi-user Scanning Probe Microscopy Facility

within the Center for Solid State Science and the X-ray Facility within the Department of

Chemistry and Biochemistry at Arizona State University for the use of its analytical

instrumentation. This work was made possible through funding from the National

Science Foundation NSF/REC-9632740

242
PROJECT 100: ACCELERATED

CO_ERCIALIZATION OF FRP

COMPOSITE BRIDGE DECK PANELS

Mark Murton

National Composite Center

2000 Composite Drive

Kettering, Ohio 45420

Telephone 937-297-9528

e-mail Mmurton @ CompositeCenter.org

243
Mark Mutton

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272
BASIC CERAMICS: FIRING TEMPERATURE

AND SIZE EFFECTS

Kurt C. Schulz

University of the Pacific

Mechanical Engineering Department

3601 Pacific Avenue

Stockton, California 95211

Telephone: 209-946-3081

e-mail kschultz @uop.edu

273
Biography:

Dr. Kurt C. Schulz was recently promoted to associate rank and assigned the role of lower

division director for the school of engineering at University of the Pacific where providing

quality undergraduate education is the primary focus. He earned a Ph.D. in 1992 from Southern

Methodist University where he specialized in the testing and analysis of advanced composite

joints. Dr. Schulz was instrumental in the development of a new engineering school in Puerto

Rico (Turabo University) and has taught at the University of Sierra Leone, Louisiana State

University and Southern University. His current focus is on the development of international ties

with the school of engineering at UOP including study abroad, work abroad and student

exchange programs.

274
Basic Ceramics: Firing Temperature and Size Effects

Kurt C. Schulz

University of the Packfic

Mechanical Engineering Department

Stockton, California 95211

USA

Key Words: Ceramics, Modulus of Rupture, Flexural Strength, Flexural Modulus, t-Test,

Hypothesis Testing

Prerequisite Knowledge: General knowledge of bonding, atomic structure and mechanical

properties of ceramic materials. Basic understanding of ceramic fabrication (firing) and the

effects of porosity and flaws on the strengths of ceramic materials. Although not mandatory, a

basic background in statistical methods, specifically the t-test, hypothesis testing and level of

significance, would be beneficial.

Objectives: There are two primary objectives: (1) to gain an understanding of the mechanical

properties, and underlying atomic structures that cause the properties, of ceramic materials

through application of Modulus of Rupture (MOR) tests, and (2) to gain an understanding of

basic statistical methods through the application of the statistical t-test to hypothesize about the

difference between population means.

Equipment and Materials:

1. Universal Testing Machine with Small Capacity Load Cell (100 to 500 lb Max)

2. 3-Point Bend Test Fixture (1.5" Span Length)

3. Rescor Cer-Cast 750 Advanced Ceramic (SIO2) Castable Mix (Base/Activator)

4. Premade Rectangular Ceramic Block Test Specimens

- One 2" X 1.5" X 0.125" Spechnen Cured at 225°F

- One 2" X 1.5" X 0.125" Specimen Cured at 1750°F

- One 2" X 0.5" X 0.125" Specimen Cured at 225°F

- One 2" X 0.5" X 0.125" Specimen Cured at 1750°F

5. PC with Data Acquisition Capability

6. Measurement Instruments: Calipers and/or Micrometers

L,ltroduction:

In ductile materials, the stress-strain behavior is generally found by applying the standard

tensile test. The stress-strain curve typically goes through a maximum that is where the tensile

strength is located (see Figure 1). Failure occurs at a lower stress after necking has reduced the

275
cross sectional area supporting the load On the other hand the stress strain behavior of brittle

ceramics is not typically ascertained using a tensile test There are many reasons as to why the

tensile test is not generally used with ceramics

1 it is difficult to prepare and test specimens having the required geometry

2 it is difficult to grip brittle materials without fracturing them

3 surface flaws often cause premature failmes and

4 ceramics fail after only about 0 1% strain thus specimens must be perfectly aligned in

order to avoid the presence of bending stresses

Due to these constraints a more suitable transverse bending test is generally used when

testing ceramics

In the bend test (or flexure test see Figure 2) a bar specimen having either a circular or

rectangular cross section is bent until fracture using a three or four point loading technique

At the point of loading the top surface of the specimen is placed in a state of compression

and the bottom surface is in tension Stress is computed from the specimen thickness the

bending moment and the moment of inertia of the cross section The maximum tensile stress

exists at the bottom surface of the center of the specimen, directly below the point of load

application Since the tensile strengths of ceramics are about one tenth of their compressive

strengths and fracture occurs on the tensile specimen face the bend test is a valid substitute

for the tensile test

For a 3 point bend test of a rectangular bar the stress at fracture using the bend test is

known as the Flexural Strength or Modulus of Rupture and is given by

3FL

_fs 2wh 2

where (sfs = flexural strength F = fracture load L = length between outer supports (span length)

w = specimen width, and h = specimen height (see Figure 2)

The results of the bend test are similar to stress strain curves however the stress is plotted

versus deflection rather than versus strain

The modulus of elasticity in bending the flexural modulus is determined from the linear

portion of the stress deflection curve and is given by

L3(F1-F2)

Efs = 4wh3(81-82)

where Efs = flexural modulus Fma x = maximum applied force 8 = beam deflection at Fma x

F 1 = 2/3 Fma x with 81 @ 2/3 Fma x and F2 = 1/3 Fma x with 82 @ 1/3 Fma x

Because cracks and flaws tend to remain closed in compression brittle materials are generally

designed such that only compressive stresses act on the part

276
There is often considerable valiation and scatter in flexural strength for many specimens of a

specific brittle ceramic material. This phenomenon may be explained by the dependence of

flexural strength on the probability of the existence of a flaw that is capable of initiating a crack.

This probability varies from specimen to specimen of the same material and depends on

fabrication technique and any subsequent treatment. Specimen size also influences flexural

strength; the larger the specimen, the greater the probability of critical flaw existence, and the

lower the flexural strength. The t-Test is a statistical method that is applied to determine whether

or not significant mean differences exist between two sets of repeated measures data. The

method will be applied to determine whether or not a specimen size effect is evident in the

Modulus of Rupture tests being conducted in this experiment.

A small sample-size test (less than 30 measurements) of the significance of the difference

between two population means may be based on the t statistic. The t-test is generally applied

when at least one of the sample sizes, n 1 or n 2, is less than 30. If the samples (tests) are random

and independent and derive from approximately Normal distributions with similar standard

deviations, then the t statistic can be applied to determine if the sample means are different:

t ,._.

xt -x2

I +1)

n 1+n2-2 _nl n2)

where21 = sample mean form the first data set,_- 2 = sample mean form the second data set,

n_ = number of data points in the first data set, n2 = number of data points in the second data set,

sa = sample standard deviation of the first data set, and s2 = sample standard deviation of the

second data set.

Recall that Sample Standard Deviation is given by

The decision as to whether or not one mean is greater than another is based on the t-sampling

distribution with n_ + n2 - 2 degrees of freedom. Applying the one-sided alternative, that21 is

Not Greater Than22 , the level of significance, a, is identified by t a as indicated in Figure 3.

The following procedure can be utilized in the application of the t-test:

1. State the Null Hypothesis as Ho: _1 Not Greater Than22

2. State the Alternative Hypothesis as HA: 21Greater Thang 2

3. Select a Level of Significance (c_): 0.05 is generally used.

4. Criterion: Using the t-table (see Table 1), determine the critical value of t_ for nl + n2 - 2

Degrees of Freedom.

5. Calculate t based on the two data sets.

6. Decision: Reject the Null Hypothesis if Itl > t=; Do Not Reject the Null Hypothesis if Ifl < t,_

277
Example: Two sets of tensile strength test data were collected as indicated below. It is thought

that Zinc Coated parts are stronger than Tin Coated parts. Use the 0.05 Level of Significance to

determine whether the Mean Strength of the Zinc Coated parts can be considered to be Greater

Than the Mean Strength of the Tin Coated parts.

Tin Coated Parts - Tensile Stength (MPa): 55, 56, 49, 61, 58

Zinc Coated Parts - Tensile Strength (MPa): 62, 63, 53, 59, 60

Answer: t = 5.404, t_ = 1.860 --_ Reject H o (_1 Not Greater Thang2) --> Accept H A

(xl Greater Than_ z )

Procedure:

Modulus of Rupture (MOR) tests will be conducted ha this experiment. The MOR tests will

involve three-point bending of specimens through application of a compressive load at the

specimen center.

1. Measure and record the Span Length, L, for the base of the fixture (all of the specimens are

nominally 2.0 inches long, but L is based on the Span Length). Record the Span Length

below.

Span Length =

2. Prior to each test, measure and record the specimen's center Width and Thickness and record

the values in the data sheet provided (next page).

3. Each group will be testing 4 specimens as indicated in the table below (one replication per

cell for each group).

4. Conduct 4 MOR tests collecting the Load versus Deflection (Stroke) data for each specimen

through brittle fracture.

5. Apply the t-Test to the combined Flexural Strength results of all of the cmTent semester lab

groups to investigate whether or not there's a Curing Temperature Effect at a 0.05 Level of

Significance:

a.) For the w = 0.50 inch Specimens.

b.) For the w = 1.50 inch Specimens.

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.................................................................................................................

0.50

............................................................................................ !:0 ................................................................................................

225

1

1750

1

278
MODULUS OF RUPTURE DATA SHEET

Test

#

Thick- Firing Width FMAX 8MAx

hess Temp.

(in) (lb) (in) (in) (oF)

F 1

(lb) On)

F 2

(ib) (in)

Flexura]

Strength

(psi)

Flexural

Modulus

(psi)

. Apply the t-Test to the combined Flexural Strength results of all groups, investigate whether

or not there's a Size Effect at a 0.05 Level of Significance:

a.) For the Specimens Cured at 225°F.

b.) For the Specimens Cured at 1750°F.

7. Show sample t-Test calculations and present your findings.

8. Write a brief Safety Analysis below that explains the potential hazards of the experiment.

(For each potential hazard, identify the potential hazard, briefly explain the potential hazard,

and then describe the steps that were, or should be, taken to protect against the potential

hazard)

9. Explain what the data means and discuss your results with respect to theoretical expectations.

10. Discuss any experimental errors that may have occurred in this experiment.

11. Make conclusions based on experimental evidence. Present your conclusions in the form of

a concise summary of your findings that you would hand to your boss; support the statements

with experimental evidence and comparisons with applicable theory.

Note: Lab Reports MUST be in accordance with the Course guidelines - See Course Website!

Comments:

As presented here, the experiment is a one-session study in which the data collected by all

students enrolled in the lab course for a given semester are compiled and analyzed by the

students. The specimens are fabricated by the instructor (a technician could be used if available)

prior to the lab. A cutout rubber sheet and flat acrylic sheet comprise the mold that is used with

a Cer-Cast castable mix to form the ceramic samples (see Figure 4 - contact author for details).

This format is excellent for an introductory materials science course with a one-credit laboratory-.

In a more advanced and/or longer formatted course, the fabrication and curing of the samples

could be assigned to the students.

279
The fu-ing effect has always been found to be statistically significant for both the smaller and

larger sample sizes. The size effect is also generally found to be statistically significant, but for

data sets with large standard deviations the strength difference can be overshadowed by data

scatter. It appears that experimental diligence is required; large data shifts are sometimes

observed between the data sets collected by different groups on nearly identical samples

(repeated measures).

Unless a statistics course is a prerequisite for the course in which this lab is conducted, the

instructor should spend some time explaining the statistical methods being applied here. At UOP

most students appear to be unfamiliar with the t-test, hypothesis testing, levels of significance,

etc. prior to enrolling in the lab course; it's important that the students not only make the proper

inferences, but they should also be capable of explaining what the resuks signify.

It should also be noted that the expressions for flexural strength and flexural modulus are

based on fundamental mechanics of materials concepts; students with a basic mechanics of

materials background should be able to derive these expressions.

References:

1. D.R. Askeland, The Science and Engineering of Materials, PWS Publishing Company,

Boston (1994).

2. L. Ott, An Introduction to Statistical Methods and Data Analysis, PWS-Kent Publishing

Company, Boston (1988).

280
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_

Figure 1 - The stress-strain behavior of brittle materials compared with that of more ductile

materials. [Askeland, 1994]

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:::::::::::::::::::::::::::::::::::::::::::::: i{ :::::::::::::::::::::::::::::::::: :::::::::::::::::::::::::::::::::::::::::::::::

Figure 2 - (a) The bend test often used for measuring the strength of brittle materials, and (b)

the deflection obtained by bending. [Askeland, 1994]

Figure 3 - Graphical Depiction of the t-Distribution. [Ott, 1988]

281
(a)

(b)

Figure 4 - (a) Photograph of the ceramic specimen fabrication materials and supplies, and

(b) Photograph of poured specimens in mold.

282
Table 1 - Percentage Points of the t-Distribution. [Ott, 1988]

283
284
USING HISTORICAL EXAMPLES TO ENHANCE

TEACHING OF "MODERN" ENGINEERING

AND SCIENTIFIC SUBJECTS

Daniel Eylon

Professor and Director

Graduate Materials Engineering

University of Dayton

300 College Park

Dayton, Ohio 45469-0240

Telephone: 937-229-2551

e-mail Daniel.Eylon@notes.udayton.edu

285
Daniel Ey|on

286
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289
290
291
292
ANTI-STOKES TRANSITIONS IN POLYFLUORENE

Bruno Ullrich

Assistant Professor

Department of Physics & Astronomy

Center for Materials Science

Bowling Green State University

Bowling Green, Ohio 43403-0224

Telephone: 419-372-7245

e-mail bruno @newton.bgsu.edu

293
Biography:

Bruno Ullfich was born in Vienna, Austria, in 1961. He received the Ph.D. degree in Physics

in 1988 from The University of Vienna. He held post-doc and lecturer positions at The

University of Strasbourg (France) and The Technical University of Graz (Austria), from 1989-

1991 and from 1991-1993, respectively. He was employed as Industrial Technology Researcher

at The University of Tokyo from 1993-1998, working on nonlinear optics and laser ablation of

II-VI compound semiconductors. From 1998-2000, he studied at the Institute of Physical and

Chemical Research (RIKEN) in Sendai (Japan) optically pumped semiconductor lasers. In

March, 2000, he joined the Department of Physics and Astronomy at The Bowling Green State

University in Ohio. His current research interests include ultra-fast spectroscopy and nonlinear

optics on inorganic and organic semiconductors and laser ablation of thin semiconducting films.

294
Anti Stokes Transitions in Polyfluorene

Bruno Ullrich

Assistant Professor

Department of Physics & Astronomy, Center for Materials Science, Bowling

Green State University, Bowling Green, Ohio 43403 0224

Key Words:

Ultrafast pulsed laser spectroscopy organic semiconductors, highly excited

semiconductors Anti Stokes transitions two photon absorption up conversion blue light

emission

Prerequisite Knowledge:

Operation of pulsed laser systems semiconductor physics optics nonlinear optics

Objective:

Up conversion To generate blue light emission at 400 nm out of an organic

semiconductol (polyfluorene) by the use of laser excitation at 800 nm

Equipment:

Fs laser system lenses optical filters neutral density filters fibers computer controlled

spectrometer

Independent Variables:

Energy gap ofpolyfluorene (400 nm i e 3 1 eV at 300 K) ambient temperature (300 K)

Dependent Variables:

Concentration of the excited photocarriers

Machine Parameters to be held constant:

Output wavelength of the laser (804 nm) pulse width (200 fs) repetition rate (249 kHz) of

the pulses

Introduction:

The Anti Stokes process lalso called two photon process or up conversion) underlies the

transition via a virtual state within the gap of a semiconducting material I e two phase

coherent photons cooperate in exciting an electron to twice the energy of a single photon

Hence the sample absorbs light to which it should be transparent As a consequence

electron hole pair generation takes place This pair generation can be detected as

photoluminescence emitting photons of greater energy than that of the exciting photons

In the current experiment polyfluorene is excited at 804 nm resulting in a blue light

emission close to 400 nm Due to reasons of probability, the intensity of the emitted blue

light depends upon the square of the incident intensity This square dependence is

checked by changing the laser intensity by neutral density filters

Procedure:

1 The experiment is started with the maximum of the available laser intensity (_109

Wcm 2) by recording the emission at 400 nm

2 Afterwards a neutral density filter, which transmits about 63% of the incoming laser

light is put in the beam and the spectrum is recorded

3 The procedure is repeated by adding neutral density filters till the impinging laser

intensity is reduced by about two orders of magnitude

The experiments are carried out in co operation with Raoul Schroeder Bowling Green

State University Depamnent of Physics and Astronomy, Bowling Green OH and

Virginia Tech, Department of Physics Blacksburg, VA Willi Graupner Virginia Fech,

Department of Physics Blacksburg VA, Ullrich Scherf Max Planck Institut fuer

Polymerfbrschung, Mainz Germany

295
296
A REVOLUTION IN MANUFACTURING

COMPOSITES: CURING WITH

ELECTRON BEAMS

Don Klosterman

Laboratory for Research on Electron Beam Curing of Composites

University of Dayton

300 College Park

Dayton, Ohio 45469-0131

Telephone: 937-229-2517

e-mail Don.Klosterman @notes.udayton.edu

297
Don Klosterman

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STUDY OF THE MAGNETOSTRICTIVE EFFECT

John Marshall

School of Applied Science

University of Southern Maine

Gorham, Maine 04038

Telephone: 207-780-5447

e-mail jmarshall @usm.maine.edu

333
Biography:

Dr John A Marshall is the Internship Coordinator for the Department of Technology at

the University of Southern Maine His areas of specialization include Power and Energy

Processing, Electronic Control Systems, Plant Layout/Material Handling, and Industrial

Distribution

334
Study of the Magnetostrictive Effect

John Marshall, Ph.D.

School of Applied Science

University of Southern Maine

Gorham, ME 04038

Abstract:

Magnetostriction is an unusual property in which a material actually changes its shape

during the application of a magnetic field. J.P. Joule using nickel first discovered this

phenomenon in 1842. Subsequently cobalt, iron and alloys of these materials were found

to show a significant magnetostrictive effect with strains of about 50 parts per million

(PPM). Applications for this material property began very slowly due to the extreme

temperature and cost limitations.

Due to recent advancements in this technology, transducers and actuators that utilize the

magnetostriction principle are becoming very popular in cutting-edge motion control

automation. These positioning sensors are replacing older, less reliable motion feedback

devices. Magnetostrictive sensors are being implemented in a variety of industrial

equipment such as injection molding machines, hydraulic presses, sawmills and many

different forms of robotic applications.

Key Words: Resolution, Hysteresis, Repeatability, Waveguide, Input & Output Signal.

Prerequisite Knowledge: Basic knowledge of magnetism and an appreciation for

accurate positioning control.

Objective: To observe and understand the concept ofmagnetostriction and to gain an

appreciation for the important contributions that this material technology

is making to automation engineering.

Equipment and Materials:

Magnetostrictive waveguide positioning sensor demonstrator unit or

components needed to demonstrate this experiment are available from

MTS Systems Corporation (www.temposonics.com).

Introduction:

Magnetostrictive materials have as a property the ability to convert magnetic energy into

mechanical energy and vice versa. As a magnetostrictive material is magnetized, it

strains, or exhibits a change in length accompanied by an inverse change in girth.

Conversely, if an external force is applied causing a strain, the materials magnetic state

changes. This coupling between magnetic and mechanical energies is the transduction

capability that allows a magenetostrictive material to be used in both actuation and

sensing devices.

335
Oneof thefirst practicalapplicationsof magnetostrictionwasits usein SONARdevices

in echolocationduringthe SecondWorld War. Anotherearlyapplicationincludedtorque

sensingandtheseapplicationsareasimportanttodayastheywerethen.

Procedure:

The magnetostrictive waveguide positioning sensor demonstrator unit requires 110VAC

as a power supply. After turning the unit on, observe the red digital measurement readout

that can be incremented in either millimeters or in inches.

Notice the inclusion of two position magnets that will be "triggering" the sensing

element. The flat magnetic ring would be utilized on a solid object such as an injection

mold housing, while the buoyant metallic "donut" would be used to sense a fluid level.

The wavegnide is the long transducer tube that extends from the head of the sensing

element. One magnetic field is generated from a current pulse that is launched along a

wire inside the wavegnide. A second magnetic field comes from the moving position

magnet, which passes along the outside of the transducer tube.

The interaction between these two magnetic fields produces a strain pulse that travels at

sonic speed along the waveguide, until the pulse is detected at the head of the transducer.

The position of the moving magnet is precisely determined by measuring the elapsed

time between the launching of the electronic pulse and the arrival of the strain pulse. As

a result, accurate non-contact position sensing is achieved with absolutely no wear to any

of the sensing elements.

Turn the demonstrator unit on and select either millimeters or inches. Slide one of the

positioning magnets onto the transducer tube and observe the readout. Simulate the

linear movement of the object or the increasing/decreasing level of fluid in a container

and observe the digital readout. Using a ruler as a confirmation tool, place it next to the

transducer tube and compare the readout to the actual distance between the positioning

magnet and the locking shaft ring.

The locking shaft ring is held in place with a small set screw. If the actual distance varies

from the displayed readout, you may need to calibrate or adjust the shaft ring. This is

easily accomplished by loosening the set screw, and adjusting the shaft ring to the linear

point when the readout matches the ruler's measurement. Gently tightening the set screw

will complete the unit's calibration.

Repeat the motion simulations described above and notice how accurate and repeatable

the positioning is being sensed and reported. Unlike traditional mechanical limit

switches or reed switches, this dependable magnetostricitive transducer accomplishes the

goal of proximity sensing without the use of contacting components.

336
Comments:

Industrial applications for these magnetostrictive positioning sensors are becoming more

numerous each day. They are being utilized on many different types of production

equipment such multiple axis injection molding machines where they monitor mold

closures. These devices are also replacing traditional contact sensors in rugged

applications such as sawmills and presses. In these applications, the magnetostrictive

sensors are reporting the position of high-pressure hydraulic cylinders that inherently

generate high levels of shock and vibration.

NASA has pioneered several new applications for magnetostrictive actuators designed to

generate motion at cryogenic temperatures. The reason for choosing a magnetostrictive

(instead of, say, a piezoelectric) actuator to obtain small increments of motion is that

magnetostrictive actuators function throughout the desired temperature range and even

work better as temperature decreases, whereas piezoelectric actuators tend to become

inoperable in cryogenic environments.

One of NASA's devices is a magnetostrictively actuated pump that has been developed to

satisfy a need for a small, low-pressure, high-flow-rate fluid pump that contains few

moving parts and can run reliably for long periods without maintenance. The pump

could be used, for example, to circulate water in the portable life-support system worn by

a fire fighter or a chemical worker or in any setting where reliability is important and

maintenance is difficult. The pump is designed primarily for water as the pumped fluid,

but it could also be used with other fluids, including cryogenic ones.

Another NASA innovation is a magnetostrictive valve for remotely controlling a flow of

liquid helium. The actuator in this valve is a magnetostrictive device surrounded by a

solenoid drive coil that generates the magnetic field needed for actuation.

The magnetostrictive filter-wheel drive is an unusual NASA mechanism that rotates an

optical filter wheel for a high-performance infrared camera or telescope. This drive could

be operated at any temperature from ambient down to near absolute zero. Moreover, in

comparison with a stepping-motor drive, the magnetostrictive drive is simpler, less

expensive, and more reliable.

An "inchworm" linear actuator is also being developed that accomplishes its push/pull

movement via a combination of magnetostriction and magnetic clamping. It will move a

mass as large as 2 kg along rails, with lengthwise position controllable in increments as

small as 50 nm. The actuator could be operated in microgravity or in normal earth

gravitation and at any temperature from ambient down to cryogenic. The actuator will be

used to position an optical assembly precisely on a long interferometer arm, as a

translation stage for a scanning tunneling microscope, and as a translation stage for

inspecting integrated-circuit chips.

337
References:

About MTS (2000) Timeline [On-line], Available:

http ://www.levelplus.com/about/timeline.html

Magnetic's Group (2000) Magnetic Materials and Their Applications [On-line],

Available:

http ://www.enc.hull.ac.uk/AP/magnetics/.../Magnetostriction/magnetostriction.html

NASA Tech Briefs, Technology Transfer, National Aeronautics and Space

Administration, Washington, DC, August 1999, Vol. 23, No. 8, p. 44 - 48.

NASA Tech Briefs, Technology Transfer, National Aeronautics and Space

Administration, Washington, DC, December 1999, Vol. 23, No. 12, p. 7b -9b.

Physics (2000) Magnetostriction [On-line], Available:

http ://www.physics.hu__.ac.uk/magnetics/Research/Faci_ities/Magnet_stricti_n/magnet_st

riction.html)

Temposonics Glossary (2000) Technology / Glossary / Magnetostriction [On-line],

Available: http ://www.mtssensors.com/glossary/glossary2.html

338
COMPOSITE MATERIALS IN

CHEMICAL ENGINEERING

Tony E. Saliba

Professor and Chairman

Chemical and Materials Engineering Department

University of Dayton

Dayton, Ohio 45469-0246

Telephone 937-229-2627

e-mail Tony. Saliba @notes.udayton.edu

339
Tony E Saliba

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OFF-SITE SCANNING MICROSCOPY

OF SILVER-COPPER ALLOYS:

FIRST STEPS TO INTERNETBASED MICROSCOPY

L. Roy Bunnell

Somhridge High School

3350 Union Loop Road

Kennewick, WA 99336

Telephone 509-734-3800

e-mail Bunnro@ksd.org

and

Stephen K. Kennedy

RJ Lee Group, Inc.

350 Hochberg Road

Monroeville, Pennsylvania 15146

Telephone 724-325-1776

e-mail skennedy@rjlg.com

359
L. Roy Bunnell

Stephen K. Kennedy

360
Off-Site Scanning Microscopy of Silver-Copper Alloys:

First Steps to Internet-Based Microscopy

L. Roy Bunnell

Southridge High School

3350 Union Loop Road

Kennewick, WA 99336

Bunnro@ksd.o1"g

Stephen K. Kennedy

RJ Lee Group, Inc.

350 Hochberg Road

Monroeville, PA 15146

Skennedy@rjlg.com

Key Words: Scanning Electron Microscopy, Precipitation Hardening, Sterling Silver, SilverCopper Alloys, Work Hardening

Prerequisite Knowledge: Students should understand how precipitation hardening works to

increase the apparent hardness and yield strength of alloys. They should have an introduction to

phase diagrams, in order to understand the limits of solubility of alloying ingredients and the role

of heat treatment in developing a microstructure of free precipitates to pin dislocations. In a

course in Materials Science Technology taught at the high school level, students are exposed to

the above concepts as part of preparation for making a sterling silver casting by the lost wax

investment casting method.

Objective: The objective of this exercise is to instruct students on how copper affects the

hardness of a silver-copper alloy, then to relate this change to microstructure as observed in

scanning electron microscope (SEM) images. This was accomplished by preparing three

different versions of a material used in the class--sterling silver--at Southridge High School in

Kennewick, Washington and to then perform SEM analysis on the specimens at the facilities of

RJ Lee Group in Pennsylvania. The resulting photographs and analytical results were

transmitted via Intemet, to see whether the structures were as expected from the phase diagram.

It is anticipated that in the near future the SEM (as well as other instruments) can be accessed

and operated through the Intemet. Ultimately, Internet access to expensive instruments makes

them a shared resource that will be within the reach of students.

Equipment and Materials: Specimens were prepared using pure (99.97%) silver and oxygenfree copper in wire form. They were melted in an electrically-heated melter, and contained in a

graphite crucible to provide a reducing atmosphere.

361
Introduction: Silver is a reasonably-priced precious metal. It is often used for jewelry, but pure

silver is too soft to have the required strength and durability. Alloying silver with 7.5 wt. %

copper produces an alloy called sterling silver. This material, when properly heat-treated, has

the copper=rich phase in the form of very fine precipitate particles. When the alloy is then coldworked, the dislocations moving through the structure are pinned in place by the precipitate

particles, producing a pronounced work-hardening effect. The work-hardened alloy is hard

enough for jewelry and tableware.

The phase diagram below (redrawn from Jacobs and Kilduff) shows the silver-copper

system.

i i ,08o

960 " / I I

(Silver-rich) (Copper-rlch)

0 8.5 %Cu _ 92.5 100 (A)

100 _ % Ag 0 (B)

Composition

Metal A = Cu

Metal B = Ag

Figure 1. Silver-Copper Phase Diagram showing starting compositions of the three samples.

The system shows typical eutectic behavior, and indicates that when heated silver-copper

mixtures will commence melting at 780 ° C, lower than either copper (1080°C) or silver (960°C).

Silver will dissolve into copper as a solid solution to a maximum of 7.5 wt. %. This phase is

seen on the right side of the diagram as "beta". Likewise, copper will dissolve into silver to a

maximum of 8.5 wt. % seen on the left side of the diagram as "alpha". Slow cooling of a melt of

sterling silver composition (Ag 92.5 Cu 7.s) should result in a two-phase mixture, composed of

silver-rich alpha and copper-rich beta. Sudden cooling of the mixture may not permit the

equilibrium amount of each phase to form. Proper heat treatment should result in a structure

composed of alpha, containing small, dispersed particles of the beta phase. This is the desired

microstructure in jewelry, since many small particles provide the best opportunity for pinning

dislocations as they move through the metal crystals during deformation.

362
Although the average composition of any sample is controlled by the original mix of metals the

nature of the phase diagram and the cooling history can result in phases of different composition

and internal structure The scanning electron microscope (SEM) can be used to examine the

composition and texture The SEM is an imaging and microchemical instrument When an

electron bean hits a specimen the electrons can be scattered back out of the specimen The

backscattered electrons detected while the beam is rastering over an area will produce an image

The number of electrons that are backscattered is a function of the average atomic number of the

specimen material In the images produced in this mode areas that are brighter are comprised of

heavier material and this image contrast allows different phases to be discriminated Phases

richer in silver are brighter than phases richer in copper Backscattered electron (BE) images

were saved to document morphology and internal structure

Electrons that are not backscattered can interact with the specimen to produce x rays The

energy of an x ray is related to the electronic configuration and the elemental composition can be

determined by acquiring and displaying the energy spectrum Peaks in the energy spectrum are

related to specific elements and the displayed peaks can be labeled with that element symbol

Using an energy dispersive spectrometer (EDS) the elemental composition of phases identified in

the backscattered electron image can be characterized It is important to note that volume of the

sample that is affected by the electron beam and from which x rays can be generated has a

diameter on the order of 2 3 micrometers Features smaller than that will have a mixed spectrum

comprising the x rays generated by the feature of interest and those of the matrix

Procedure: Materials used were pure (99 97%) silver purchased as 1 oz coins, and oxygen

free copper wire These were melted at 1000 ° C in a graphite crucible and heat treated as

follows

Specimen #1 contained twice the sterling amount of copper (15 wt %) and was slow cooled

from melting in order to develop a coarse microstructure showing the rejected excess copper

silver phase

Specimen #2 contained the sterling amount of copper and was quenched ha water after melting

to develop a f'me microstructure in which much of the copper is still in solution

Specimen #3 had the sterling silver composition like #2 except that it was quenched from 770 °

C to produce a supersaturated solution at room temperature Finally the specimen was heated to

300 o C for 30 minutes to develop the desired fine microstructure During the final step the

hardness of the alloy is reported to double as a result of this structure

The specimens were sent to RJ Lee Group Inc for metallographic preparation and examination

by scanning electron microscope (SEM). Each specimen was sectioned using a diamond blade

saw and mounted in Lucite The mount was polished using 3 micrometer then 1 micrometer

diamond paste Each mount was given a thin coat of carbon to prevent charging while under the

electron beam

363
Eachsamplewasexaminedatlow and high magnification. Each phase observed was also

characterized by EDS analysis. Results are below.

Comments: The microstructure of Sample #1, containing twice the sterling amount of copper

and slow-cooled, is as shown in Plates A, B and C. Plate A shows that there are two phases and

they display an ordered microstructure. A bright silver-rich (alpha) phase occurs as laths

approximately 50 um wide (Plate B) and is also interspersed with the darker copper-rich beta

phase (Plate C).

The structure of Sample #2, of sterling composition and quenched, also shows two recognizable

phases. The presence of laths (Plate D) indicate that there was sufficient time in the quenching

process to form crystals, but that the laths are smaller in width (about 10 um) and there is a

smaller amount of the darker phase. Plate E shows that the bright phase is the silver-rich alpha

phase, and Plate F shows that the darker phase is the copper-rich beta phase.

Sample #3 was of sterling composition and heat treated to develop the fme precipitates. Plate G

shows that the interior (to the left) of the sample has no apparent structure other than an

occasional small dark phase. Plate H demonstrates that the bright phase is silver-rich and

contains a small amount of copper. The exterior rim of the sample (to the right) shows the

presence of a second phase. Plate I shows the bright phase in the rim to be silver-rich and

copper free. Plate d shows that the small dark occurrences in the rim are copper that has been

oxidized. It appears that the heat treatment has driven the copper out of the silver phase to form

discrete copper oxide. Plate K is a line scan for copper and shows the decrease in copper in the

bright phase from the interior (left) to the exterior (right) of the sample.

This SEM microscopy is the first step in a connection via Intemet between students and

expensive and specialized instrumentation. The images in this paper will be shared with the

students in high-school Materials Science Technology classes. In the near future, it is hoped that

high-school students in the classes will have real-time access to this instrumentation.

References:

Jacobs, J. A., and Kilduff, T. F., Engineering Technology: Structure, Properties and Selection,

Third Ed., 1997, Prentice-Hall, Pages 258-261.

364
Plate A

Plate C

Plate B

Plate D

Plate A - BE image of Sample #1 showing the presence of two phases. Plate B - BE images

and EDS spectrum of Sample #1 showing the bright phase is silver-rich with a small amount of

copper. Plate C - BE images and EDS spectrum of sample #2 showing the dark phase is

copper-rich. Plate D - BE image of Sample #2 showing the presence of two phases.

365
Plate E Plate F

Plate G

!_um

Plate H

Plate E - BE images and EDS spectrum of Sample #2 showing the bright phase is silver-rich.

Plate F - BE images and EDS spectrum of Sample #2 showing the darker phase is copper-rich.

Plate G - BE image showing the interior of Sample #3 (left) to be primarily a bright phase with

scattered dark occurrences and the sample exterior (fight) to have a 250 um rim with

concentrated dark phase occurrences. Plate H - BE images and EDS spectrum showing the

bright phase in the interior to be silver-rich and containing copper.

366
Plate I Plate J

Plate K

Plate I - BE image and EDS spectrum of

Sample #3 showing the bright phase in the rim

to be copper-free silver. Plate J - BE image

and EDS spectrum of Sample #3 showing the

dark phase in the rim to be a copper-rich

oxide. Plate K- BE image and copper line

scan illustrating the reduction in copper from

the interior (left) to the exterior (right) of

Sample #3

367
368
UNIVERSITY- INDUSTRY COOPERATION AND

INSTRUCTION IN MATERIALS

SCIENCE AND ENGINEERING:

GOOD INTENTIONS AND REALITY

Witold Brostow

Victor M. Castano

and

Pablo E. Montemartini

University of North Texas

Materials Science Department

P. O. Box 305310

Denton, Texas 76203-5310

Telephone: 940-565-4358

e-mail brostow@marta.phys.unt.edu

castano@marta.phys.unt.edu

pem0005@unt.edu

369
370
University - Industry Cooperation and Instruction in Materials Science and

Engineering:

Good intentions and reality

Witold Brostow, Victor M. Castafio and Pablo E. Montemartini 1

Department of Materials Science, University of North Texas, Denton, TX 76203-5310, USA;

1. Introduction

The link with the productive sector has been a continuing concern of people entrusted with

defining general policies of universities and colleges. Many universities have special offices,

which provide the link. However, there is a paradox here: successful links are rare. In spite of

the effort expended, there is much less success that one would expect.

Institutions of higher education would like to participate, in a direct and effective way, in

the impressive social changes brought about by the available XXI century technologies. In

this paper we consider the basic features of the problem: how should we provide instruction in

Materials Science and Engineering (MSE). Needless to say, the objective is to provide college

graduates able to perform well in the society, have social mobility, and able to sustain personal

growth. In Section 2, 3, and 4 we shall consider these three aspects in some detail.

1 presenting author

371
2. Training to work

We begin with the standard premise: colleges prepare students with the characteristics the

companies require. Do the companies know what will happen in the future? Do they

extrapolate into the future?

Of course, a modem university must qualify students for work, but work in conditions

and in jobs that they will face during the next 50 years: great competition, innovations,

managerial attitude and generation of own resources. The new professionals have to be able to

solve real national problems in the technical, social and economic environment of the XXI

Century World and to produce wealth.

3.The social mobility

The social mobility represents one of the more important promises of the universities in all

countries, especially developing ones. Therefore, we should offer a model of a university that

guarantees the social mobility. The model should be based on flexible and interdisciplinary

curricula, capabilities for student _exchange (nationally and internationally - as it is already

practice in Europe) and the development oft_he managerial attitude. A direct relationship with

the - already existent or potentials - wealth generating sources is pertinent also.

4. Personal growth.

Our students should adquire from the university clear positive examples of those cases in

which "the urgent does leave time for the important". Unfortunately, the discussion about the

current educational policies is mainly based on technical training. Human values are hardly

contemplated in the curriculum design stage and even less in actual instruction.

We have here not only a moral or ethical problem, but also a practical one. We are

forming young people for whom thevatues of solidarity, companionship, decency, modesty

and integrity deserve the same - not less - attention that a world trade course, re-engineering or

372
ISO-9000. There has to be a reflection on the social consequences of an individual act.

Moreover, our universities provide graduates with access to the consumption, but not

necessarily with the social codes needed to understand the consequences that their behavior has

for other individuals and for the environment. Practicing MSE has in fact strong consequences

for the environment.

5. Teachers

One of the most recurrent concerns in the field of education is training and updating of

instructors. Since one cannot provide what one does not have, it is clear that the efforts of

modernizing the education should start with faculty training and updating. In MSE instruction

we need to combine the current status of technology (which change continuously) with a vision

of the future. For instance, how shall we use smart materials in the year 2025? Some specifics

on this issue will be provided in the talk.

We know what needs to get done; in this respect the present paper reiterates ideas

already known. The point of gravity is in procedures (including details) which will enable the

implementation of our well-intentioned ideas.

373
374
MASS TRANSFER SENSORS AND

MEMS DEVICES TO MEASURE SHEAR

Vijay Modi

Department of Mechanical Engineering

Columbia University in the City of New York

3000 Broadway

New York, New York 10027

Telephone: 212-854-2956

e-mail modi @ columbia.edu

375
Vijay Modi

376
Mass Transfer Sensors and MEMS Devices to Measure Shear

Vijay Modi

Department of Mechanical Engineering

Columbia University

Key Words

Microelectromechanical Systems, Solid State Devices, Materials, Fluid Dynamics, Shear

Prerequisite Knowledge

Basics of physics, chemistry and engineering mathematics

Objectives

The measurement of shear is of great interest to fluid dynamics research, cellular biology,

aerospace, marine, environmental and biomedical engineering since shear is the primary means

of interaction between a flow and the solid surface. Several critical areas of technology rely on

an accurate knowledge of local shear such as heat transfer in turbine blades, electrochemical

etching/deposition of copper, metallization using wet- processes in advanced electronics and

microfabrication of high-density patterned structures, colloidal transport in environmental

engineering and validation of computational fluid dynamics simulations.

A discussion of the need for such measurements is provided along with a brief review of

existing techniques for measurements. An electrochenfical mass transfer based technique that

permits shear measurement in liquids over a five order of magnitude range of shear with a 100

micron spatial resolution is described. The future challenge lies in developing

techniques/devices to measure shear in gases at length scales that are of the order of 1 to 100

microns and time scales on the order of microseconds. In this regard the development of a novel

MEMS device is described.

Equipment and Materials

Hot-wire anemometry, Electrochemical Mass Transfer Probe, Microfabrication

Techniques,

Introduction

The measurement of shear is of great interest since shear is the primary means of

interaction between a flow and the solid surface. Shear is the genesis of drag and it is frequently

an important factor in determining the rates of processes such as removal/deposition of particles,

transport of heat and chemi_ species at a wall. Several critical areas of technology rely on an

accurate knowledge of local shear such as heat transfer in turbine blades, electrochemical

etching/deposition of coppel; metallization using wet- processes in advanced electronics and

microfabrication of high-density patterned structures, colloidal transport in environmental

engineering and validation of computational fluid dynamics simulations. Measurement of low

377
levels of shear is also of importance to the field of biomedical engineering. Shear stress on

endothilial cells in macrovascular beds is related to injury to cells. The ability to measure the

associated low levels of shear would provide a means to quantify their relationship to injury and

disease. In most applications noted above the shear levels typically range from 0.1 to 40 Pa.

The relevance of shear to heat and mass transfer applications is well understood. Lofdahl

and Gad-el-Hak [ 1,2], recently reviewed shear sensors, pressure sensors and their importance to

turbulent flow _ntrol. Some of the novel future applications of shear sensors are however likely

to come from biological and biomedical applications. In most prior biomedical research

applications the wall shear is deduced from the measurement of bulk velocity or flow rates. Since

the flows are generally laminar, an estimate or measurement of the size and assumed shape of

vessel suffices to determine shear. Some such studies are: the work by Moore and Glagov (3) (an

attempt to understand the relationships of flow field properties to the localization of plaque

relating to atherosclerosis in humans), Wechezak and Viggers (4) (effects of fired-generated

shear stress on cells undergoing mitosis and cytokinesis), Irace and Carallo (5) (mechanisms

underlying macrovascular complications), Takahashi and Okuda (8) (role of shear in mediated

gene expression) and Jacobs et al (10) (bone mechano-transduction). Such studies indicate the

ned _br a direct measurement of shear.

Indirect Measurement

Traditional techniques such as a Stanton gauge, Preston tube or a sublayer fence are

indirect measurements of shear and rely on pressure measurement. [11-14] They rely on accurate

machining, calibration and small pressure differential measurement. For a good review, see

Goldstein [ 15].

Another indirect technique relies on heating small thermal elements near or flush with the

wall. The element is maintained at a constant temperature and the heating current is related to the

local wall shear stress (16). Fage and Falkner (17) were the first to study the relationship

between local walt shear and the rate ofheat transfer from small thermal elements. Tillman (18)

used this technique to establish the law of the wall for turbulent boundary layers. Some designs

are flush mounted (I6), or with wire protrusions of only I micron into the flow, so there is

minimum interference with the flow. They are also fast reacting and small enough to measure

turbulent flows. Elements as small as I2.7 grn were developed(17) with a frequency response

upward of 300 kHz (19). The repeatability of calibration and frequency response of the sensors

is limited by the inability to completely insulate the sensor from everything but the flow. This is

particularly difficult for the flush mounted sensors which otherwise have the advantage of not

interfering with the flow. The relationship between the heat transfer and the shear itself changes

with the nature of the flow and is difficult to establish analytically in turbulent flows which are

not boundary layer type flows, e.g. impinging flows.

We have recently used hot-wire anemometry to carry out velocity measurements within

the viscous sublayer for the purpose of determining the local wall shear on an impingement plate.

These measurements represent the first direct measurement of shear in turbulent impinging slot

jets. The distance from the wall to the edge of the viscous sublayer varies with Reynolds number.

With a specially designed boundary layer probe from TSI, we will be able to make mean and

turbulence intensity measurements at y* as small as 2.5 along the wall in all regions except

perhaps the region immediately below the jet. There are three features of this technique that

permit accurate measurement of shear. First, the calibration of the hot-wire is carried out in the

378
same near wall position as that used in the measurement using a flat-plate boundary layer with a

known Blasius solution. This permits one to account for the effects of the wall on the hot-wire

calibration without any assumed correlation. Moreover this has the advantage of permitting

calibration of the wire for much lower velocities than otherwise possible with the use of a micromanometer. Second, a non-contact optical method is used to determine the wire distance from

the wall. Third, mechanical design of the probe assembly ensures that the distance between hotwire and the wall remains the same during the measurement of the distance, calibration of the

probe and the actual measurement of the velocity.

Electrochemical Mass Transfer Probe

Another technique that our group (A.West, D. Yang, B. DeBecker, M. Chen and V.

Modi) has used relies on an electrochemical technique described by Hanratty in the volume

edited by Goldstein (15). In our studies a mass transfer sensor consisting of a 0.1 mmx 20.3 mm

(= Lx w,) platinum foil, cast in a cylindrical mold is used. The sensor design equation provides a

relationship between the Nusselt number Nu and the wall shear stress given in terms of a skin

friction coefficient, Cf (evaluated at the sensor's midpoint, i.e. x M). The relationship can be

shown to be:

Nu = 1.0lo_Scl/3cf 1/3 Re 2/3

where°_=IO+f_/z-O-f_"2f '3wheref -f: 7ML .2[_M

Some of the advantages of this approach are that the probes are flush mounted, so this

technique does not disturb the flow. The frequency response is largely limited by the measuring

equipment and the size of the sensor. For the present sensor it was possible to acquire data in a 1

to 10 kHz range. The probe can also be used to examine turbulent flows without making any

special assumptions about the behavior of the turbulent Prandtl or Schmidt numbers as long as

the sensor is sufficiently small. There are no substrate losses, as with thermal techniques and

hence the system can be calibrated analytically. A particular limitation is however the need to

carry out the experiments in a liquid system with a specified chemistry. The flow cells must be

constructed out non-metallic or stainless steel materials. Hence most applications of this

approach are for model laboratory experiments. In the following section the use of

microfabrication techniques for making small but rugged probes is discussed.

MEMS Based Sensors

MEMS devices can also becomes tools for research into the understanding of fluid flow

and heat/mass transport since they provide the ability to sense and measure at physical scales that

are becoming smaller. Their small physical scales may also allow the combination of sensing,

actuation and control of flow for systems of much larger scale with applications in the

automotive, aerospace, structural, manufacturing, and process industries.

Indirect measurement

One example of such a device is a micro thermal shear-stress sensor. This is a MEMS

built heated flush-mounted thin-film that uses the thermal method of determining shear. A

379
drawbackof usingthin films in thermal shearmeasurementsensorsis that smallerthe sizethe

greaterthe fractionalIossesto thesubstrate,thusreducedsensitivity. Thedesignersof thismicro

sensor(20) reducedthis problemby usingMEMS to creatinga thin vacuumcavity underthe

sensor,which insulatedthe thin film sensorfrom the substrate.With this techniquethey were

ableto designa sensorof dimensions80-200gm, with afrequencyresponseof 70kHz.

Direct Measurement

Padmanabhan et al(21) used MEMS fabrication techniques to suspend a 125 _n square

by 7 _ thick silicon element by four 300 _un long thin tethers. The square dement partially

shaded two photodiodes from a laser that shined down onto the element. As the shear force from

fluid flow moves the element, one of the photodiodes would be further shaded, and the other

uncovered. The difference in electric current from the diodes was translated into shear force.

This is first successful example of a direct measurement of force for evaluating shear at a sub

millimeter physical scale. Packaging of this design into a self-contained probe poses a difficulty

because of the need for an external laser light source.

The goal of our present effort is to develop a MEMS-based shear stress sensor that will

be from 10 to 100 microns across. Hence the external size of our packaged sensor will be of the

same order of magnitude as a current MEMS-based pressure sensor. These devices are typically

cylindrical in shape, and have a packaged size of roughly l lure diameter by 5 mm long. We are

currently developing a sensor that consists of a cantilevered beam, with a larger flat surface at

the end of the beam exposed to the shear force. This shear force can be order of 0.1 to 1

nanoNewtons leading to deflections of the fiber tip on the order of several nanometers. The

measurement of a differential electrostatic force applied to the beam to contact pads at either end

of the sensor surface provides a means to establish the shear force. A schematic of the design is

shown in the figure.

References:

(1) Lofdahl L. and Gad-el-Hak M., MEMS-based pressure sensors and shear stress sensors for

turbulent flow, Meas. Sci. and Tech., 10, 665-686, 1999.

(2) Lofdahl L. and Gad-el-Hak M., MEMS applications in turbulence and flow control, Prog.

Aero Sci, 35, 101-203, 1999.

(3) Moore, JE., Xu CP., Glagov, VS., Zafins, CK., Ku, DN, Fluid wall shear-stress

measurements in a model of the human abdominal aorta, Atherosclerosis 110, 225-240, 1994.

(4) Wecgezak, AR, Viggers, RF, Coan, DE, Sauvage, LR, Mitosis and cytokinesis in

subconfluent endothelial cells exposed to increasing levels of shear-stress, J. Cellular

Physiology, 159, 83-91, 1994.

(5) Irace C, Carallo C, Crescenzo A, Motti C, De Franceschi MS, Mattioli PL, Gnasso A

NIDDM is associated with lower wall shear stress of the common carotid artery, Diabetes, 48,

193-197, 1999.

(6) Oyre S, Paaske WP, Ringgaard S, Kozerke S, Erlandsen M, Boesiger P, Pedersen EM,

Automatic accurate non-invasive quantitation of blood flow, cross-sectional vessel area, and wall

shear stress by modeling of magnetic resonance velocity data, European J. Vascular and

Endovascular Surgery, 16, 517-524, 1998.

(7) Khder Y, Briancon S, Peterrnann R, Quilliot D, Stoltz JF, Drouin P, Zannad F

Shear stress abnormalities contribute to endothelial dysfunction in hypertension but not in type II

diabetes, J. Hypertension, 16, 1619-t625, 1998.

380
(8) Yan C, TakahashiM, OkudaM, Lee JD,Berk BC, Fluid shear stress stimulates big mitogenactivated protein kinase 1 (BMK1) activity in endothelial cells - Dependence on tyrosine kinases

and intracellular calcium, J. Biological Chemistry, 274, 143-150, 1999.

(9) Sirois E, Charara J, Ruel J, Dussault JC, Gagnon P, Doillon C J, Endothelial cells exposed to

erythrocytes under shear stress: An in vitro study, Biomaterials, 19, 1925-1934, 1998.

(10) Jacobs CR, Yellowley CE, Davis BR, Zhou Z, Cimbala JM, Donahue H J, Differential effect

of steady versus oscillating flow on bone cells, J. Biomeehanies, 31,969-976, 1998.

(11) Stanton, T.E., Marshall, D., Bryant, C.W., On the Condition at the Boundary of a Fluid in

Turbulent Motion, Proc. Royal Society, London Ser. A, 97, 413-434, 1920.

(12) Hool, J.H., Measurement of Skin Friction Using Surface Tubes, Aircr. Eng., 28, 52, 1956.

(13) East, L.F., Measurement of Skin Friction at Low Subsonic Speeds by the Razor-Blade

Technique. Aero. Res. Count. London, R&M, 3148, 1959.

(14) Bradshaw, B.A, Gregory, M.A., The Determination of Local Turbulent Skin Friction from

Observation in the Viscous Sub-Layer, Aero. Res. Coun. London, R&M, 3202, 1961.

(15) Goldstein, R.J., Fluid Mechanics Measurements, Hemisphere Publishing Corporation,

NY, NY. 1983.

(16) Liepmann, H. W. , Skinner, G. T., Shearing-Stress Measurements By Use of a Heated

Element. NACA TN 3269, 1954.

(17) Fage, A., Falkner, V.M. On the Relation between Heat Transfer and Surface Friction for

Laminar Flow Aero. Res. Count. London, R&M No. 1408, 1931.

(18) Ludwieg, H., Tillman, W., Investigation of the Wall Shearing Stress in Turbulent Boundary

Layers, NACA TN 1285, 1950.

(19) TSI Corporation Web site, www.tsi.com. 1998.

(20) Huang, J., Liu, C., Jiang, F., Tung, S., Tai, Y., Ho, C., Fluidic Shear-Stress Measurements

Using Surface-Micromachined Sensors. Proc. IEEE Region 10 Conf. Mieroelectronics and VLSI,

Hong Kong, 12-15, 1995.

(21) Padmanabhan, A., Goldberg, H,D., Breuer, K.S., Schmidt, M.A., A Silicone Micromachined

Floating-Element Shear-Stress Sensor with Optical Position Sensing By Photodiodes, 8 th Int.

Conj. On Solid State Sensors and Aetuators, Stockholm, Sweden, Jun 25-29, 436-439, 1995.

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THE MAGSET PRO_CT

MATERIALS AS THE GATEWAY (AND GLUE)

FOR SCIENCE, ENGINEERING AND TECHNOLOGY

Don L. Evans

Director, Center for Research on Education

in Science, Math, Engineering, and Technology

Arizona State University

Tempe, Arizona 85287-5006

Telephone: 480-965-5350

e-mail devans@asu.edu

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TECHNOSPHERE. AN ENVIRONMENTAL

STUDIES SEMESTER FOR UNDERGRADUATE

MATH, SCIENCE, ENGINEERING, AND

TECHNOLOGY MAJORS

Leonard W. Fine

Department of Chemistry

Columbia University in the City of New York

Havemeyer Hall

New York, New York 10027

Telephone: 212-854-2017

e-mail fine @chem.columbia.edu

and

Morton Friedman

Columbia University

500 West 120th Street

Room 510 Mudd

New York, New York 10027

Telephone: 212-854-2986

e-mail Friedman@columbia.edu

395
Leonard W Fine

396
TECHNOSPHERE. An Environmental Studies Semester for Undergraduate Math,

Science, Engineering, and Technology Majors.

Leonard Fine, Department of Chemistry and Morton Friedman, Department of

Civil Engineering

Columbia University, New York, NY 10027.

Key Words

Education, Mathematics, Science, Engineering, Technology, Chemistry

Environmental Studies

Prerequisite Knowledge

None

Objectives

This is a time of powerful forward momentum for engineering and applied

science and for chemistry, physics and mathematics. Ours is an era marked by

sophisticated, rapidly changing, all-pervasive technology, and by physical sciences and

applied mathematics that universally transform the way we live and how we work. At the

same time, we live in global environments that demand local attention. It has been said

that these are the best of times and perhaps they are, but the pessimist fears that truth. Our

greatest responsibility to successors is to make them more aware of the context of their

actions. TECHNOSPHERE semester is an integrative, seven-course curriculum of

interdisciplinary education presented at Columbia University's Biosphere 2 campus to

take advantage of the unique research and education opportunities on the campus and in

the Biosphere 2 facility. This semester curriculum has been developed to take advantage

of growing awareness of planetary issues. The program emphasizes engineering and

science field studies while stressing integrative research, technology development, and

applied science. The curriculum allows students to meet standard second-year

engineering and science requirements as they gain hands-on experience in real world

applications of course content. Courses are structured to focus on the junctures of

engineering curriculum elements with energy and other planetary management challenges

readily demonstrated by a variety of campus surroundings. The authors will describe the

program in words and pictures and provide wisdom on which - schools and students -

should consider participating, and how to do it.

Equipment and Materials

Six biomes - ocean, rainforest, swamp, savanna, desert and agricultural - under a

3.1 acre glass dome enclosure that permits careful control of light, heat, and atmosphere.

397
Teehnosphere Semester

This is a time of powerful forward momentum for engineering and applied

science and for chemistry, physics and mathematics. Ours is an era marked by

sophisticated, rapidly changing, all-pervasive technology, and by physical sciences and

applied mathematics that universally transform the way we live and how we work. At the

same time, we live in global environments that demand local attention. It has been said

that these are the best of times and perhaps they are, but the pessimist fears that truth. Our

greatest responsibility to successors is to make them more aware of the context of their

actions. To that end, Columbia University is committed to helping resolve what we

perceive as a defining issue for the 21 s' century - the environment. The western campus

at Biosphere 2 provides engineering and science students with an opportunity to study the

Biosphere, the real world of our experience, in context.

Technosphere Semester is an integrative, seven-course curriculum of

interdisciplinary education for undergraduate engineering and science majors students

presented at Columbia University's Biosphere 2 campus to take advantage of the unique

research and education opportunities on the campus and in the Biosphere 2 facility. This

semester curriculum has been developed to take advantage of growing awareness of

planetary issues as an appropriate element of the Columbia core curriculum concept of a

full cultural education foundation for every undergraduate student.

The program will emphasize engineering and science field studies, integrative

research and science seminars that include a seminar taught jointly with Earth Semester,

Universe Semester, and Technology Semester faculty and directed at how the Biosphere

- planet earth - works. The curriculum will allow students to meet standard second-year

engineering and science requirements as they gain hands-on experience in real world

application of course content. Courses are structured to focus on the junctures of

engineering curriculum elements with energy and other planetary management challenges

readily demonstrated by a variety of campus surroundings.

The campus focuses students on Biosphere-related studies and provides a

surrounding, expansive real world learning venue that demonstratively enriches the

curriculum. The campus offers a semester abroad like immersive experience with

significantly reduced distraction from curricular content. Students have immediate

opportunity to apply the skills they are developing in the real world. In addition to its

advantageous relative proximity to Sandia and Los Alamos National Laboratories, the

campus presents a natural setting for study of cogeneration; environmental pollution

challenges from mining and other industrial/commercial activities; and hydrology and

water supply and pollution issues.

398
Course summaries

Physics: Introduction to elements of the three-term physics sequence, modified to

include relativity, waves, quantum theory and quantum mechanics, reflection and

transmission, properties of nuclei, fourier series and integrals, normal modes, uncertainty

and wave-particle duality, stressing with environmental applications. This course has an

experiential research component to be introduced by the Universe Semester faculty. 3

credits.

Mathematics: Introduction to elements of ordinary differential equations with

applications to Biosphere 2. Mathematical modeling is introduced as a predictive tool in

understanding dynamic atmospheric, ocean and earth systems as they are impacted by

human behavior. This is equivalent to the standard Ordinary Differential Equations

(ODE) course for engineers and scientists. 3 credits.

Chemistry: Introduction to structure and dynamics of the planet at the macro and micro

scale. Equilibrium dynamics of solids and fluids in earth and planetary environments.

Contaminants, adsorbates and interfaces provide a new approach to the traditional

principles of introductory chemistry. Materials science and chemical physics provide the

basis for understanding relevant environmental applications. The laboratory component

of the course is both field study-based and distance learning in conjunction with

laboratory classes in New York. 3 credits.

Energy: Broad introduction to the science (30%), technology (40%), economics (20%)

and policy (10%) of energy systems. Includes energy and power, units, energy density

and power density. Review of thermodynamics, vapor and air-standard power cycles.

Car/truck/aircraft engines, steam and gas turbine power plants. Combined cycle gas

turbines, cogeneration or combined heat and power. Renewable sources of energy. Wind

turbines, farms, and storage systems. Solar photovoltaics, storage systems, hydrogen,

fuel cells, and carbon problems. Open to students with first year physics and

mathematics completed. 3 credits.

Energy Conversion Systems Laboratory: This instrumentation intensive laboratory

course will include experiments on instrumented micro gas turbines, photovoltaics, fuel

cells and wind turbines; measurement of temperature, pressure, flow velocity, flow rates.

Students will develop familiarity with sensor and actuator use using workstations

designed for multimedia learning in a laboratory. The course will subsequently expose

students to the more complex sensor network of Biosphere 2 and the control software, hot

wire and hot film anemometry. Students will be introduced to use of oscilloscopes,

elementary circuits and software for data acquisition. 3 credits.

399
Integrative Technology course on how the Biosphere works - The Mechanical

Biosphere: Brings Technology students into nine lectures taught by the Earth Semester

Faculty, with the remaining 18 lectures to be taught by Universe and Technosphere

Faculty in chemistry, physics, mathematics, statistics, and engineering. This course is

open to all Biosphere 2 undergraduates. 3 credits.

An alternative open to Technosphere Semester students is to take the Planetary

Management Module as elective credit.

Math, Science, Engineering, and Technology Seminar: A two-hour weekly integrative

seminar, drawing on the resources of the Earth, Universe, and Technology programs in a

given semester, as well as from visiting scientists and engineers. It will include 4 to 6

field trips that feature power generation, cogeneration, hydrology and water issues,

uranium production and nuclear waste disposal, chemical pollution, and other subjects.

Field trips will include such sites as Hoover Dam, the Asacrco open pit mines, the Bisbee

deep mine, the Grand Canyon, and the Department of Energy's (DOE) Sandia and Los

Alamos National Laboratory facilities. 2 credits.

Independent Research- All students will be expected to work and study under

Technosphere Semester faculty mentors, Biosphere 2 engineering and chemistry research

faculty and staff, University of Arizona faculty and researchers, and other mentoring

opportunities to be made available to them. Examples of individual projects include

work in chemical and mechanical engineering with sensors, detectors and sniffers,

building research equipment and sensing devices, long term laboratory development

projects, instrumentation tracking projects to continue over several semesters,

hydrological chemistry applications, studies of campus facilities and phenomena for their

chemical and engineering facets, smart or green building design, or innovative

transportation and energy concepts. Students must earn a minimum of 4 credits in

independent research. 4 credits.

Supporting Research Programs in Chemistry

Effect of Environmental Conditions on Ecosystems - The glass-enclosed Biosphere 2

not only allows environmental conditions within it to be varied in a carefully controlled

manner, but also results in an environment inherently different to that of the biosphere.

By varying the atmospheric composition and environmental conditions inside Biosphere

2, and monitoring the effect of these variations on the enclosed eco-systems, detailed

investigations on how ecosystems chemically respond to varying environmental

conditions are possible. In addition, by comparing and contrasting systems within

Biosphere 2 and the same systems in the biosphere, we can systematically investigate

how chemical responses in systems adapt to different environmental conditions.

Chemistry of Biotic Interaction - The Biosphere 2 laboratory provides a unique

opportunity for research in chemical communication and chemical defense mechanisms

of species under relatively simplified ecological conditions. Conducting research of this

400
type in the Biosphere 2 allows for isolation, bioassays and characterization at the site of

collection, under "natural" conditions, resulting in more meaningful results. At the same

time the closed structure of Biosphere 2 also allows introduction of species into the

enclosure in a controlled manner making possible studies on the socio-biological and

chemical factors that determine the success or failure of species survival.

Chemical and Biological Studies of "Artificial Systems" - The Biosphere 2 laboratory

provides numerous opportunities to investigate life under controlled conditions. The

construction of an artificial ocean provides a particularly appealing opportunity to study

how terrestrial life adapts to aqueous saline environment. Evaluating which organisms

now thrive in the Biosphere 2 ocean will lead to significant knowledge of the short-term

saline environment adaptation process. This information will provide significant insight

into the overall process of adaptation and will, on the longer time scale, yield data on the

rates of salinity-tolerance evolution.

Stable Isotope Studies of Nitrous Oxide Biogeochemistry - Despite being present in

only trace amounts, in the atmosphere, nitrous oxide (N20) exerts a disproportionately

large influence on the terrestrial climate. Yet, the global budget of N20 is presently not

well quantified. We are interested in undertaking isotopic studies of N20, especially

those that can be uniquely studied in the Biosphere 2 laboratory, such as the biological

production of N20, to improve our understanding of N20 biogeochemistry. A better

understanding ofN20 biogeochemistry would help produce models that better predict

atmospheric responses to human activities.

Environmental Sensors - The research areas described above will require parameters

like atmospheric composition, humidity, temperature, and light intensity to be carefully

controlled, varied and monitored. Feedback systems that sense changes and respond to

these changes will be required, as well as on-line and field-site analysis of air, soil and

water. All of these measurements and controlling devices can take advantage of microelectro-mechanical (MEMS) technology. This technology is the basis for devices that

monitor pressure and temperature, detect low levels of hydrogen, hydrocarbons, and

nitrogen oxides, and control operation of miniature robots, and micropumps. The group

of researchers involved in this area will work closely with the researchers in the above

four groups designing MEMS devices that can be used for their applications. Given the

relevance of such devices for an economy and industry that is increasingly

environmentally conscious, this group will include scientists and engineers from the

industrial partners to ensure that the technology being developed is viable for industrial

applications.

SUPPORTING RESEARCH PROGRAMS IN ENGINEERING

The emergence of MEMS (micro-electro-mechanical systems) and nanoscale

sensors in the past 20 years has decreased dramatically the size, weight and cost of

sensors and sensor arrays by orders of magnitude, while at the same time improving their

spatial and temporal resolution and increasing accuracy. Thus, in systems that previously

were limited to one or a few sensors, emerging technologies make it possible to conceive

401
of possibly thousands of sensors integrated into systems to improve their performance,

increase their lifetime, make them more flexible in use, and decrease their life cycle

costs. The integration of sensors with electronics has opened new modes of recording and

transmitting data, particularly by wireless transmission. These open up new and exciting

possibilities for the Biosphere 2 research laboratory and will be of interest to DOE in

particular.

It has become possible to incorporate arrays of sensors into systems in ways that

often expose them to hostile environments that include high temperatures, high vibration,

high noise, or corrosive chemicals. In biological systems, sensors can be developed that

themselves do not affect the system or organism. The interest in new sensing and

imaging technologies and critical applications for these technologies is ubiquitous across

all science and engineering disciplines. Hybrid electrical-mechanical-biological sensors

are one of the most promising new frontiers of the microelectronics revolution. There are

new and emerging sensor technologies that were virtually unknown five years ago and

that can be applied to the solution of critical problems. To quote a Defense Advanced

Research Projects Agency (DARPA) mission statement: "It is a revolutionary, enabling

technology that can completely change the way people and machines interact with the

physical world."

As we noted in the abstract, this is a time of powerful forward momentum for

engineering and applied science and for chemistry, physics and mathematics. We believe

we are stepping into the 21st century with an innovative and timely collaborative program

that can set new standards for educating the next generation of scientists and engineers.

402
OVERVIEW OF MATERIALS SCIENCE AND

ENGINEERING LABORATORY

PREVIEW NEW:UPDATE 2001

Gale A. Holmes

Polymers Division (854)

Polymers Building (224), Room B116

National Institute of Standards and Technology

100 Bureau Drive, Stop 8543

Gaithersburg, Maryland 20899-8543

Telephone: 301-975-5280

e-mail gale.holmes @nist.gov

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Gale A. Holmes

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USING MST-ONLINE TO IMPROVE INSTRUCTION

James A. Jacobs

Department of Technology

Norfolk State University

700 Park Avenue

Norfolk, Virginia 23504-8060

Telephone: 757-823-8109

e-mail jajacobs @nsu.edu

and

Curtiss E. Wall

Norfolk State University

700 Park Avenue

Norfolk, Virginia 23504

Telephone: 757-823-9571

e-mail cewall @nsu.edu

429
Curfiss E Wall

430
Using MST-Online to Improve Instruction

James A. Jacobs and Curtiss E. Wall

Norfolk State University

Norfolk, VA 23504

Key Words: Computer, Internet, CD-ROM.

Prerequisite Knowledge: Basic computer literacy and use of the World Wide Web.

Objectives: To use the gateway web site < Http://MST-online.nsu.edu > for introductory

concepts on materials, science, and technology. To make links to materials science and

technology educational resources, including materials research efforts from national labs,

universities, and corporations as well as to technical societies and educational institutions that

have web sites with downloadable instructional resources.

Equipment and Supplies: An Internet connected computer. A computer running at least

500mhz with a 800 x 600 screen is preferred.

Introduction: Beginning in 1990 with a grant from IBM Corporation, we have been using

computers to enhance technology instruction at Norfolk State University (NSU). In 1998 we

conceived the idea of expanding our efforts into the world wide web (www). We planned to

develop a site that provide educational resources in math, science and technology (MST) built

around materials science and technology (MST). We developed the site as a "gateway website"

or portal. The site provides basic MST concepts that link to federal laboratories, technical

societies, other universities, and corporations.

The basic concepts build on the textbook, Engineering Materials Technology, by James A.

Jacobs and Thomas F. Kilduff. To graphically augment those concepts, we obtained images

from numerous sources including museums, NASA, technical societies, manufacturers and

fellow educators.

With support from NSU and NASA Langley Research Center, we were able to build

MST-Online. MST-Online can serve as your portal to web based materials education.

Procedure: Open up your web browser and type mst-online.nsu.edu on the line reserved for the

url or uniform resource locator. The home page for mst-online should appear.

431
Move your mouse to the area of the page containing the appropriate screen size and press the left

mouse button. The main menu page should appear.

You are now ready to use the resources ofmst-on|ine. At that point you can directly link to the

sponsors. Click on NASA Langley to gain access the their site,

Welcome to MST Online

New

and

NoRo_k State Universi_

Question& Comments:

Jim _.

432
then click on

structures and

materials research

to get into

NASA's Center of

Excellence for

Structures and

Materials.

__ ___ @ _ _ ........................................

been _n_ra_ner_ )n sf_oing _erospace N _t_rV for more

ei_ decades. EstalNcJned in 1917 as tt_e first

national ci'dt _ narcs _bof_ory, NASA LI_l_ff_,y l_

become a worid-cla._ cer_r _r _, _._r_n

i i_il

iiiiiiiiiiiiiiiiiiiii i_i__!i ii ii _iiiiiiiiii_iiiii! .

433
Notice that the MST-onIine

menu is still at the top of

your screen. If you click on

Hot Links

Mot Links you will

be taken to the page that

connects to external links.

Each area has its own

button to access a page of

links. For instance, ifyou

click on ceramics, the

following page will be

displayed.

_ii_iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_ %iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_q _iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii!_%iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_i ?_%iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_ii<_iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_%iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_ _=::%iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii_' %iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii ............................

Ceramics

MST-online has a valuable set of reference material for you to access. If you select one of the

other items from the menu at the top of the screen such as Metals Met_ks you will be

taken to a section in the Engineering Materials Technology book on metals. At this point you

434
are presented with

a frame containing

the main menu at

the top of the page,

an introductory

page in the frame at

the bottom of the

page. On the

introductory page

there is a sub menu

for exploring

different aspects of

the main topic.

ZvSetaZs

Throughout

MST-Online

diagrams and

pictures are

available for

examination. If we

choose Phase

Diagrams under

Metals, a new page

will be presented.

This page, dealing

with phase

diagrams, has more

detailed

information,

including a line

which displays a

link to Figure 5-9.

Clicking on that link

will bring up a unary phase

diagram of water. This diagram is

displayed directly below the web

page for Phase Diagrams.

_iiiiiiii_ iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii iiiiiiiiiiiiii

1 tl, _,,_,_'it,i-I-lltitl,*.<E --_3 "-<< ......... ' <'_"--i "<'_`_'_'''_" 7_"" .........

PI_ASE DIAGRAMS (EQUILIBRKTM DIAGRAMS) FOR METALLIC SYSTEMS

A

B

"re._rat_¢e ¢,K)----->

435
Conclusion: The use of the world wide web to access information not otherwise available to

students is exciting in itself. However, the real revolution in education may be the use ofhyper

links to present this information in new ways. Certainly, Apple's hyper book and Toolbook and

Linkway for DOS computers were the beginning of this innovation, but the combination of

hypertext tools and the vast amount of information stored on computers throughout the world

will revolutionize our teaching. In the future, the use of streaming video and audio will further

expand the potential of this learning tool. We should remember that this is only one tool that we

are able to employ, and hands on learning is still an important component of the learning process.

As a gateway website, MST-Online provides the portal to many other sites. The dynamics of the

Intemet is such that these sites should be constantly providing fresh information and instructional

resources for you and your students.

436
THE BLACK BOX

Mike L. Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, California 95616

Telephone: 530-752-5166

e-mail mlmeier @ucdavis.edu

437
Biography:

Michael L. Meier received his B,S in Materials Engineering from North Carolina State University

in 1979 and his M.S. (1986) and Ph D. (1991) in Materials Science and Engineering from the

University of California, Davis. After atwo-yearpost-doctorate position at the Universit_itErlangenNfirnberg in Erlangen, Germany he returned to UC Davis where he is the director of Materials

Science Central Facilities and teaches many of the laboratory courses

438
THE BLACK BOX

Mike Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, CA 95616

USA

Key Words: theory, hypothesis, scientific method

Prerequisite Knowledge: none

Objective:

In this experiment the student is given a closed, sealed black box which contains one or more small

objects. The immediate goal is to figure out what is inside the box. The ultimate goal is to get one's

colleagues to concur. The overall objective is to learn something about science and to initiate a

discussion of the nature of science.

Equipment and Materials:

1. Black boxes (Radio Shack part 270-1807)

2. Simple objects to put inside the boxes, such as nuts, bolts, ping pong ball, twigs, dice, wood

blocks, coins, rubber ball.

Introduction:

The goal of science is the acquisition of new knowledge. But there are rules, rules which tend to

make science seem cold and impersonal, and there is a process, something which tends to make

science appear to be the boring domain of eggheads. But to those who "do" science it is a series of

puzzles to assemble, discoveries to be made, a grand quest to understand our universe. This

experiment is designed to give you an introduction to the rules and the process, and a taste of what

it is like to participate in this quest. The books listed in the references offer additional perspectives,

both amusing and very serious, on the goals, nature and issues confronting modern science.

Science is a social activity practiced by individuals, groups and nations. It is essentially a debate in

which theories, hypothesis, experiments, objective observations, things people associate with

science, are merely elements. As a debate it is very demanding, with some hard rules and strict

requirements: rigorous logic, testable hypothesis, and most of all the requirement that you must be

able to back up your claims with hard evidence.

It may seem that there are different sorts of science. In some fields, the thing being studied can be

held in your hand, poked and prodded, and disassembled on the laboratory bench. In others it may

be trillions of miles away and billions of years in the past. In geology, the earth itself is the

specimen and the processes being studied may require from seconds to eons to run to completion.

In the social sciences the "specimens" are so complex that it seems unlikely that they will ever be

able to enjoy the level of success enjoyed by the physical sciences. Some science is data-driven,

439
others theory-driven. Some sciences are quantitative while others are mostly qualitative; some are

data-rich and others data-poor. Furthermore, the tools and methods the scientist uses can be as

unique as any particular investigation, as unique as each scientist, and as unique as the field of study.

The Experimental Method: One might say that science is a product of the experimental method, the

process of isolating the variables important to the study and investigating the relationship of each

variable to the phenomenon in question. This is indeed one of the main tools of scientists and it has

also provided us with sound theories that can explain the nature of extraordinary things we deal with

in everyday life, things we will never be able to see with our five senses, but theories so convincing,

so well explained and so well supported by experiment and employed in things we use everyday that

we may have come to think of as ordinary.

Scientific Theory: The product of science is the scientific theory. A theory is a statement that

attempts to explain the nature of something. It is the end product of a series of tests performed that

prove or disprove a series of more general statements, or propositions (hypotheses), It is not, as

many people tend to think, a guess.

Most scientists will agree that for a theory to be considered a scientific theory it must possess the

following characteristics:

• Falsifiability, or rentability, or testability

• Supported by the evidence

• Makes predictions

Besides defining scientific theory, these three requirements place restrictions on the things that can

be investigated scientifically. Many questions simply can not be answered by scientific

investigations.

The Scientific Method: Many of us have been taught that the scientific method involves the

following:

• Select something in nature to study

• Develop hypotheses about how it works or how it relates to other things

• Pursue this hypothesis until it yields unique and testable predictions

• Test the hypothesis

• Repeat, refining the hypothesis until a theory can be formulated

In practice, the actual method of doing scientific is hardly as neat and tidy as the one described

above. While the process of acquiring this new knowledge almost always requires careful, focused

effort, scientific discoveries may also involve luck and even fortuitous accidents, or a unique way

of looking at things, or knowledge and experience that few other people have. So while it may seem

like a grand personal adventure while you are "doing" science, it becomes a public debate when you

publish it.

The Scientific Publication: The appearance of tidiness in the scientific method can be blamed on

440
the published scientific paper. In it one describes the evidence, the methods and observations in

clear, concise and logical manner so as to build a solid argument that supports your conclusions. In

these papers one does not describe the accidents, the dead ends and the early mistakes that produced

no results. The scientific publication also tends to make science appear cold, dry and impersonal.

But as mentioned above, doing science isn't cold, dry and impersonal, and scientists aren't, but the

results must be.

Each author is aware that the publication is not only an announcement of new findings, it is also an

invitation to one's peers to criticize the work. And they will. It is not fun to have one's own theory,

the product of hours (or years) of work, shot down in flames in a public arena. But when it happens

it is both necessary and healthful. And always remember, the burden of proof is always on the

author a fact that makes doing science as difficult and demanding as it is rewarding.

Procedure:

Testing: Examine the box. Find out what you can about the box and then devise ways to determine

what is inside the box. Once you have made a few observations you will be able to formulate an

initial hypothesis. With further testing you will be able to refine your hypothesis until you have

learned as much as you can about the object in the box. While you are not allowed to open the box,

you are welcome to use any tool and instrument in the laboratory to help gather the information you

need to be able to make a final, definitive statement as to what the object is.

The Results: What do your tests indicate regarding the mass, size, shape, material and other

properties of the object in your black box? What do your tests tell you about the black box itself?.

What do you think the object is?

The Report: Now that you have decided what the object probably is, you'll need to write a formal

report that tells your peers about your investigation and how you determined what the object is.

Before you start writing, review the goal of the experiment. A well thought out and well stated

objective is essential to the writing process and for the reader's understanding of your report. Next,

review each of the tests you performed and the information you got from each. Using this

information, develop the argument for the conclusion you will make. Finally, state clearly what you

think the object is, if you can. Now, write it up.

Peer Review: Share your report with your colleaguesl Loan them your box and watch them do the

same experiments you did, using your report as a guide. Or maybe they will use the techniques they

used when studying their box and will be able to teach you something new about your mystery

object. If your colleagues agree with you, well that is reassuring, but there still remains a certain

amount of uncertainty as to what the object or objects really are. That is one of the characteristics

of even the best of theories. If, on the other hand, someone disagrees and can show you good

evidence that is contrary to your findings, errors in your logic, or can offer an alternative explanation

that is consistent with your observations, then that when the fun really begins.

Comments:

Our students seem to enjoy this experiment. After shaking and tipping their box a few times they

become hooked and are determined to figure out what is in the box. The mood changes, however,

441
i

,i

after being reminded that they have to write up their findings. They start taking notes and start

trying to be a little more systematic in their investigation. At this point I like to point out that many

investigations may start out poking and prodding and just trying different things in an effort to try

to get a handle on the problem.

After the students turn in their reports I ask them if their account of the experiment presents the

procedures, results and explanations in a clear, concise and logical manner and if it makes a

convincing case for what the student thinks the object is. The answer is usually yes, or something

close to yes. Then I ask them is their report accurately depicts how the study was actually done. The

answer is usually no.

We often conclude that there are several dimensions to doing science and that the finished product

may look a lot neater, tidier, impersonal and even more boring than what actually happened. We

may eventually get around to talking about how important it is to know as much as possible about

the subject before starting a study, but at the same time how those things that make each of us unique

can make a real difference, and that everyone brings something different to science. We may

conclude the experiment with a discussion of the importance of peer review, and finally I

recommend a few books (see references) that they offer fun and interesting perspectives on science.

References:

1. I.Amato, Stuff, The Materials the World is Made Of, Avon Books, Inc., (1997).

2. J.Hatton and P.B.Plouffe, Science and Its Ways of Knowing, Prentice Hall, New Jersey (1997).

3. A.Cromer, Uncommon Sense, Oxford University Press, Inc. (1993).

4. A.K. Dewdney, Yes, We Have No Neutrons, John Wiley and Sons, Inc., New York (1977).

5. W.Hartston, Drunken Goldfish and Other Irrelevant Scientific Research_ Sterling Publishing Co,

Inc., New York (1988).

6. F.Balibar, The Science of Crystals, McGraw-Hill, New York, (1993).

7. P.Gross and N.Levitt, Higher Superstition, The Johns Hopkins Academic Press, Boston (1994).

442
PARAMETER SELECTION IN AUTOMATIC

GAS METAL ARC WELDING

Alessandro Rengan

Mahmoud Abdallah

and

John Mingus

Central State University

Manufacturing Engineering Department

1400 Brush Row Road

Wilberforce, Ohio 45384

Telephone: 937-376-6429

e-mail arengan@ csu.ces.edu

443
Biography:

Dr. Alessandro Rengan obtained his B.S. degree in Metallurgy from the Indian

Institute of Technology, Madras, India in 1974. He earned his M.S. degree in Materials

Engineering from the University of Dayton in 1977 and completed a Ph. D. in Materials

Science and Engineering from North Carolina State University in 1992. His major

research interests are in the area of ultra hard coatings. He is currently an associate

professor at Central State University, Wilberforce, OH, USA.

Dr. Mahmoud Abdallah obtained his B.S. degree in Electrical Engineering from

Ain Shams University, Cairo, Egypt. In 1974. He earned his M. S. degree in Electrical

Engineering from the University of Rochester in NY in 1981 and completed his Ph.D. in

Electrical Engineering from the University of Toledo in 1986. He is currently a full

professor at Central State University, Wilberforce, OH, USA.

John Mingus obtained his B.S. degree in Mechanical and Materials Engineering

from Wright State University in !994. He is currently a technician at Central State

University, Wilberforce, OH, USA.

444
Parameter Selection in Automatic Gas Metal Arc Welding

Alessandro Rengan, Mahmoud Abdallah and John Mingus

Manufacturing Engineering Dept.

Central State University

Wilberforce, OH 45384

Abstract:

Gas Metal Arc Welding (GMAW) processes are economical and can be used in

automatic or semi-automatic equipment. A large number of weld parameters are available

for control, however, and inadequately developed welding procedures can result in less

than optimal quality welds. The Design of Experiments (DOE) approach is the most

efficient method of identifying the key input factors that optimize the response and

minimize the cost. The use of DOE will be discussed to evaluate the optimal parameters

that control weld quality.

Key Words: Welding, Robotics, Design of Experiments, Parameter Selection

Prerequisite Knowledge: Basic knowledge of welding processes, that is, types of

oxy-fuel welding and arc welding techniques. Statistical analysis of laboratory results

including some design of experiments.

Objective: To understand the use of design of experiment approach to optimizing the

quality of GMAW welds.

Equipment and Materials:

.

2.

3.

4.

5.

6.

Robotic GMAW Welder (preferred).

If not, semi-automatic GMAW can suffice.

Low carbon or mild steel cut to size.

Tensile testing machine.

If not, less accurate results can be obtained with a hardness tester.

Grinding wheel.

Safety Precautions:

°

2,

3.

4.

5.

.

Helmet mask is required.

Leather apron and gloves.

Use of a welding curtain if bystanders are present.

Eye safety goggle is required when using tensile testing equipment.

Normal care must be taken to avoid electrical shock when handling the welding

equipment.

Fumes from the welding operation must be adequately vented.

445
Introduction:

A major manufacturing process in operation today is welding. Of the many types

of welding techniques available, the gas-metal arc welding (GMAW) - or MIG welding

process is most amenable for robotic applications. This is due to their simple torch

design, good deposition rates and tolerance to joint fit up. Robotic welding offers many

advantages such as repeatability, high productivity and good quality. However, due to the

large number of control variables involved many welding operators do not thoroughly

understand how to optimize arc weld-quality. Thereby the speed and maneuverability of

the robotic system is not efficiently utilized. The resulting inadequately developed

welding procedures have high defect rates, and poor quality in regard to satisfying the

requirements of the final product once it is in service.

The technician must determine several primary-welding parameters. These

include current, voltage, wire feed speed, travel speed, torch angle and position,

shielding-gas flow rates, and electrode extension.

A typical GMAW welding station contains a power supply that delivers an

operator set constant voltage, a wire feeder that feeds the filler wire from a coil to a

welding gun, and controls for setting welding parameters such as voltage, wire feed and

travel speed, and electrode extension. The welding current is proportional to the wire feed

speed to maintain a constant melting rate. A power supply applies the necessary current.

Selection of the welding voltage must take into consideration the wires alloy type,

wire diameter, type of shielding gas being used, electrode extension, and current.

Welding voltage, once set, controls the length of the welding arc, or the distance between

the tip of the electrode and the work piece. Adjusting the wire feed speed will control the

actual current level. The gun, or welding torch, supplies the welding electrode and

shielding gas. The robot controls the welding gun travel speed and positioning.

To optimize the quality of the weld a design of experiments approach was

utilized. For the statistical analysis a choice of response or dependent variable was the

tensile strength of the weld bead. Next the factors to be varied was selected, the primary

weld parameters are voltage, V, wire feed rate, W, and travel speed, T. The choices of

two levels of these factors were quantitatively estimated from discussions with people in

the field, and from the literature. Due to the expected variation of the results five

observations were to be taken at each level and the order of experimentation was to be

randomized. This is a 2 3 factorial experiment, the mathematical model for this experiment

and design would be:

Yijkm = _t + Ti + Wj + Vk + TW o + TVik + WVjk q- TWVijk + [3m(ijk)

Where Yijkm represents the measured variable, tensile strength, p., the true mean of

the population, Ti the travel speed effect, Wj the wire feed rate effect, and Vk the voltage

effect. Also i = j = k = 1,2. _rn(ijk)represents the random error in the experiment where m

= 1,2,3,4,5. The other terms stand for interactions between the main factors, T, W, and V.

446
The hypothesis to be tested was that there was no type of travel speed effect, no wire feed

effect, no voltage effect, and no interactions.

Experimental:

An Automatix robot system was used with a AI32 controller. For the welding

application a welding gun could be fixed to the robotic arm. When the system is equipped

with welding equipment and software it is called Robovision II-600. The operator can use

the Integrated Command Module (ICM) to include WELD statements into the program

created from the ICM. The WELD commands direct the robot to move along a path with

the welding arc turned on. The welding parameters (travel speed, wire feed rate and

voltage, etc) for each weld, are contained in tables referenced as "weld schedules".

Selecting different schedules may change these parameters. Once the Robovision II-600

is in place, the AI32 controller overrides the setting on the welder. Every command is

therefore remotely controlled.

The shielding gas used for the GMAW purpose was 100 % CO2 gas. A butt joint

assembly made out of 1/8" thick low carbon steel (type 1120) bar was used to make test

welds on two 3" long pieces. The electrode was 0.030" diameter ER 70S-6. A constant

voltage power supply was used in reverse polarity. The travel speeds of 6 and 12 in./min

were selected. Wire feed rate of 150 and 180 in./min were chosen. And voltages of 23

and 28 V were used. Tensile testing was done on a SATEC 60 UTS machine.

Results:

The analysis of this experiment consisted of collecting 40 items of data in a

randomized manner. The results in pounds of tensile load to fracture the samples are

given in Table I.

Table I

Tensile Load necessary to fracture welded specimens in pounds.

Travel Speed

6 in/min

Wire Feed

150 in/min

180 in/min

23 V

Voltage

1933 Ibs

1933

3600

1145

2200

4066

3200

3866

3800

28 V

3800 Lbs

2066

1434

1561

1666

3066

4922

4866

4546

447
2866 4934

12 in/min

150in/min

180 in/min

1533

1466

3733

1066

2476

80OO

3066

4500

3066

2666

2066

2733

3466

2933

2866

4933

4866

3466

4000

5066

This experiment and the mathematical model suggest a three-way analysis of

variance (ANOVA) which yields the results in Table 2.

Table 2

ANOVA for Tensile Breaking Load of Welded Specimens

Source of Variation

Degrees of Sum of

Freedom Squares Mean Square

Travel Speed T 1 105.6 105.6

Wire Feed W 1 3626.2 3626.2 *

Voltage V 1 205.9 205.9

T x W interaction 1 0.6 0.6

T x V interaction 1 0.8 0.8

W x V interaction 1 10.6 10.6

T x W x V interaction 1 144.1 144.1

Error _ 32 10791 337.2

Totals 39 14885

At the 5-percent significance level (ix = 0.05), the critical region of 'F' is F >

4.15. Comparing each mean square with the error mean square indicates that only one

hypothesis can be rejected: Wire Feed Rate has no effect on the tensile breaking load.

None of the other hypothesis can be rejected and it is concluded that only the Wire Feed

Rate (indicated by an asterisk) affects the tensile breaking load. Travel Speed and

Voltage appears to have little effect On the tensile breaking load, and all interactions are

negligible. Calculations on the original data of Table 1 show the average tensile breaking

loads given in Table 3.

448
Table 3

Average Tensile Breaking Loads of Welded Specimens

Parameter Value Avg. Tensile Load

Travel Speed T 6 in/min 3073 Lbs

12 in/min 3400

Wire Feed W 150 in/min 2283

180 in/min 4190

Voltage V 23 V 3008

28 V 3462

These averages seem to bear out the conclusion that Wire Feed Rate affects the

tensile breaking load with the 180 in/min requiring a higher tensile load than the 150

in/min wire feed rate.

Graphing all four 'wire feed rate' and 'voltage' combinations in Figure 1 shows

the meaning of no significant interactions.

(Lbs.)

5000

4000

3000

2000

1000

150 180

in/min

Figure l. Tensile Breaking Load Vs. Wire feed rate and Voltage interaction.

A brief examination of this graph indicates that the tensile breaking strength is

increased by an increase in the wire feed rate. The fact that the line for the 28 V is above

the line for the 23 volts shows that the 28 V weld implies a slightly higher tensile

breaking load. The fact that the lines are nearly parallel is characteristic of no interaction

between two factors. Or, it can easily be seen that an increase in the wire feed rate

produced about the same average increase in the tensile breaking load regardless of

which voltage was used. This is another way to interpret the presence of no interaction.

449
Conclusion:

I.

2.

3.

4.

Automatic GMAW has numerous parameters that can be varied to give welds

with different tensile breaking loads.

A three-factor experiment with two levels was designed and the data was

analyzed by a three-way ANOVA with five observations per cell.

From the results it was shown that only one factor (wire feed rate) affected the

tensile breaking load.

It was also determined that within the range of the experiment it makes little

difference which voltage and travel speed are used, and that there are no

significant interactions between the three factors.

References:

.

2.

Fundamental Concepts in the Design of Experiments. Charles R. Hicks, Third

Edition. Pub: Holt, Rinehart and Winston, Inc. 1984.

"Weld Parameter Development for Robot Welding" Dennis D. Harwig, Robotics

Today, 10, 1 (1997) 1-7.

Acknowledgements:

The authors would like to acknowledge the efforts of three seniors who worked

on this project for their senior design. They are Ibrahim Cisse, Oumar Diallo and

Victorien Ndounou.

45O
LAB MANUAL & RESOURCES FOR

MATERIALS SCIENCE, ENGINEERING

AND TECHNOLOGY ON CD-ROM

James A. Jacobs

and

Alfred E. McKenney

Department of Technology

Norfolk State University

700 Park Avenue

Norfolk, Virginia 23504-8060

Telephone: 757-823-8109

e-mail jajacobs @nsu.edu

aem2 @prodigy.net

451
Alfred E, McKenney

452
LAB MANUAL & RESOURCES for MATERIALS SCIENCE,

ENGINEERING AND TECHNOLOGY on CD-ROM

James A. Jacobs and Alfred E. McKenney

School of Science & Technology

Norfolk State University

Norfolk, VA 23504

jajacobs@nsu.edu

NEW:Update Site - http://MST-Online.nsu.edu/newO 1

Key Words

CD-ROM, materials, experiments, papers, NEW:Update, workshop, structure, testing, evaluation, metals,

polymers, ceramics, composites, electronic, optical, curriculum

Prerequisite Knowledge: Familiarity with Adobe Acrobat Reader. (See the Getting Started

section, at the end of this paper.)

Oblective: To assess experiments, demonstrations and other resources on the EMSET2 CD-ROM for

adaptation to classroom and laboratory instruction related to materials science, engineering and

technology.

Equipment: Windows: Microsoft Windows 95 or higher, Windows NT with Service Pack 3 or later.

Apple: Power Macintosh, Apple System Software v7.1.2 or later. UNIX: Solaris 2.3 (both SPARC and

Intel processors), HP-UX 9.05, IRIX 5.3, OSF/1 4.0, AIX 4.1.

Acrobat Reader v4 with search and QuickTime v4.

Abstract

The National Educators' Workshop (NEW:Update) series of workshops has been in existence

since 1986. These annual workshops focus on technical updates and laboratory experiments for

materials science, engineering and technology, involving new and traditional content in the field.

Scores of educators and industrial and national laboratory personnel have contributed many

useful experiments and demonstrations which were then published as NASA Conference

Proceedings. This "out poring of riches" creates an ever-expanding shelf of valuable teaching

tools for college, university, community college and advanced high school instruction. Now,

more than 400 experiments and demonstrations, representing the first thirteen years of

NEW:Updates have been selected and published on a CD-ROM, through the collaboration of this

national network of materials educators, engineers, and scientists. The CD-ROM utilizes the

popular Adobe Acrobat Reader format and operates on most popular computer platforms.

This presentation provides an overview of the second edition of Experiments in Materials

Science, Engineering and Technology (EMSET2) CD-ROM, ISBN 0-13-030534=0.

453
Backqround- Annual NEW:Updates & Publications

The National Educators' Workshop (NEW:Update) series of workshops has been in existence

since 1986. NEW:Updates focus is on strengthening materials education through technical

updates and publication of laboratory experiments and demonstrations for materials science,

engineering and technology, involving new and traditional content in the field.

The National Aeronautics and Space Administration (NASA), the Department of Energy (DOE),

National Institute of Standards and Technology (NIST), and Norfolk State University (NSU),

have provided the major funding for these workshops. Joining in support are the American

Society for Engineering Education, ASM Intemational, American Society for Testing &

Materials, Battelle Pacific Northwest Laboratory, Boeing Airplane Company, Ford Motor

Company, Martin Marietta Energy Systems, Inc, The International Council for Materials

Education, Oak Ridge National Laboratory, DaimlerChrysler, General Motors and Gateway

Coalition.

Workshop participants witness presentation of experiments and demonstrations, developed by

faculty, scientists, and engineers throughout the United States. They discuss issues of MSE

(materials science and engineering) with people from education, industry, government, and

technical societies, and hear about new MSE developments. Half-day mini workshops in small

groups are conducted in state-of-the-art laboratories at the host laboratories including NASA

Langley Research Center, National Institute of Standards and Technology, Oak Ridge National

Laboratory, Los Alamos National Laboratory, Boeing Airplane Company-Seattle, Columbia

University/Brookhaven National Laboratory, University of Michigan/DaimlerChrysler.

An extensive peer review process of experiments is followed. After submission of abstracts,

selected authors are notified of their acceptance and given the format for submission of

experiments. Experiments are reviewed by an international panel through the cooperation of the

International Council for Materials Education. Authors receive comments from the panel prior to

workshops allowing them to make necessary adjustments to their experiments. Participants who

attend NEW:Updates, observe demonstrations of the experiments and provide critiques for the

authors to make further modifications prior to this publication. Final editing has been done by

the publication staff of the National Aeronautics and Space Administration.

The CD-ROM Compendium

After several years of NEW:Update Workshops and the popularity of the experiments resulting

from the meetings, the organizing committee, with assistance from the Materials Division of

ASEE, began work on a compendium of selected experiments. Support for this collection came

from a broad range of individuals, agencies, and technical societies, much like the support for the

NEW:Updates Workshops themselves.

The original idea aimed to produce hard copies of about 50 selected experiments. However, at

NEW:Update 94, Alfred and Evelyn McKenney and Robert Berrettini presented a concept by

which all experiments could be placed on a CD-ROM in a format that would provide materials

educators an easy way to find and use any of the experiments. Additionally, instructors could

454
customizetheexperimentsto meettheir students'needs.After furtherresearchonmethodology

andeffortsto securefunding,wewereableto put togetheraprojectthatusedseveralsourcesof

funds,muchvolunteerhelpandresources,andapublisherwho wouldproduceandpackagethe

EMSET CD-ROMs from the master and distribute them.

The structure of EMSET allows materials educators to manipulate individual papers in a variety

of ways for either hard copy or digital output. They can edit their selection to fit their own

environment and to suit their students' needs. The first edition of EMSET, containing papers

from the first decade of the Workshops, was released in 1997. This second edition, EMSET2,

containing an additional three years of papers and expanded teaching content, was published in

the fall of 2000.

EMSET2 Content

The EMSET2 CD-ROM

contains three major

sections as shown on the

Main Menu in Fig 1.

The INTRODUCTION TO

EMSET2 section

contains further

information about

EMSET2's content,

contributors and

provides help in getting

started.

The ADDITIONAL

I_SOURCES section

contains supplemental

teaching material.

Examples are shown

below.

Fig 1 - Main Menu

The EXPERIMENTS & DEMONSTRATIONS section contains over 400 demonstrations and

experiments. It is the heart of the NEW:Update workshops and the EMSET2 CD-ROM and is

further described below.

455
While it is difficult to demonstrate the richness of the teaching resources contained in EMSET2,

in a brief space, we will present some description and examples of its content over the next few

pages.

The Additional

Resources Section

This section contains a

wide range of material

aimed at providing

instructors with

additional resources to

supplement their

classroom curriculum.

This material ranges

from a short course on

microscopy for advanced

composite materials, an

extensive listing of

relevant web sites,

through applications of

materials, photos,

photomicrographs,

structures and models.

There are examples on

this page and the next:

MICROSCOPY OF FIBER-REINFORCED

POLAR CO_OSITES

InS Uctors

L., M. Gammon

_eatue, washiffgton

B. S. Hayes

Univers.ityof Washington

Seattle; Washington

Course Overview

This course is designed t0 educate both the practitioner and novice on

the analysis and understandingof Compositematei'ia_susing optical mieroscopy.All aspects of thisfieldwilt be covered,frOmsamplepreparation

techniques,including thin section development, tomethodsofmicroseopy

analysis. Thiscourse will be highlighted by case studies and, further,by a

hands.on laboratorysession;

¢- 1- " ........... hq

Fig 2 - A Short Course on Microscopy of Fiber-Reinforced Polymer

Composites

456
Fig 3 - Application of Materials in the Automotive Industry

Color changes guide the heat treatment of a drum. In this exemple, a kerosene

fired heat source produced a flmne of approximateily 600 degz?ees Celsius. The

maker placed a dr rut[ upside-de_nl over the h eat_ Lawrence E. Murr and Ever aldo

Ferreyra Tello, Pand_moniuln Steel Drum _selnble. "Connecting Materials Science

and Music in Steel Drums" _merican Scientist, January, 2000.

Fig 4 -Applicationof Materialsin the Fieldof A_

457
Experiments & Demonstrations Section

This section includes over 400 experiments and demonstrations in PDF format from the annual

NEW:Update workshops. They have been reproduced in their original peer-reviewed form,

preserving the individuality among the papers and reflecting the author's style and method.

The TABLE OF CONTENTS

classifies the papers into

seven categories:

Structure, Testing &

Evaluation, Metals,

Polymers, Ceramics,

Composites, Electronic &

Optical Materials and

Materials Curriculum.

To find the document(s)

meeting your needs, the

user can:

- Browse the Table

of Contents which

is organized by

types of materials

or processes, or

- Use the full Text

Search capability,

searching by:

Author

Title

Subject

Text words in context

& Evaluation

ites

7. Materials Curriculum

............ _ .... __..= ..........

Fig 5 - Table of Contents

The PDFs are indexed for full text search when using the ADOBE TM ACROBAT READER WITH

SEARCH program. The "word stemming" and "sounds like" features are enabled to allow the

greatest freedom in locating the content desired.

While the detailed Table of Contents can also be scanned to find the material desired, the user

will probably use the Full Text Search more often because the subject matter of papers

sometimes fits into more than one category.

Once located, the ACROBAT READER gives the user the ability to:

- View an exact image of the original paper,

- Read, or print the paper, or copy its text into another document for editing.

The following page demonstrates the power of the "word stemming" capability. The search word

"hardness" finds such occurrences as "harden," and "hardening."

458
EXPERIMENT

TESTING AND EVALUATION hardness

L Hiiden_ K. L_wis, A, Meamaripour i

EFFECT OF TEMPERATURE (

Richard Brindo

TRA

Fig 6 -

EXPERIMENTS AND DEMONSTRATIONS IN STRUCTURE,

TESTING AND EVALUATION

EFFECT OF TEMPERATURE O]

Richard Brindos and Gun_ _

Kyo D. Song and Hcidi R. ii

Stephen J. S¢otfi arid Sang

THE AFPLIC_,TION OF (X)MI_

(_ 023 Be-Cu Precipitation Hardening Experiment

o--= :-.= ;_-:_ J [11=

O 069 Application of Hardness Testi_ n Foundry Processing

_' 085 Scleroscope Hardness Testing

__,_-. ,-_ ;

RATES FOR METAI._ IN AQUEOUS SOLUTIONS

R. B, Griffin, L 1_ Comweil, and Holly E, Ridit_gs - Texas A&M Unive_ity

EXPERIMENTS SHOWING DYNAMICS OF MATERIAL INTERFACES

Robert F. Benjamin - Los Alam¢_ Natkmal Laboratory

Fig 7 - Showing some of the Full Text Search results for "hardness," using Word

Stemming

Selection of the first page of the highlighted paper is shown on the next page.

459
Usinq the

Papers

In many cases, you

will probably use

the experiments as

they were

published.

However, you may

sometimes wish to

edit a paper for a

particular need,

even combining it

with other papers.

You can use the

Acrobat Exchange

program. However,

if you do not have

IT'S P_RD TO TEST HARDNESS

Edward L. Widener PE.

Purdue University-MET. Department

W, Lafayette, IN 47907

ABSTRACT

Hardness is essentially a mechanical prOperty of uniform

materials, a surface indicator of other properties. It is hard

tO define, hard to correlate different tests, and hard to

cow, are different materials. Nevertheless, hardness is broadly

considered as _reslstance to penetration, elastic and/or

plastic. _ For metal alloys, commercial tests typically measure

plastic-straln or part, anent-set for solids; resultant

scratches or dents are relatively non-destructlve, unless

stress-concentrations in finished surfaces make trouble.

With dozens of hardness tests available, our conventional

lab experiments te_d to focus on a pair Of popular industrial

machines, Brinell and Rockwell, and to generate repetitive

data for common metals by routine operations. Technologists

are not clerks but problem-solvers, in need of an early

exposure to a variety of tests, which involve diverse

principles and definite applications. Selecting appropriate

methods and following published standards are priority lab

_b_ectlves • Details of several unconventional experiments°

with and familiar )les, are ested to

access to this Fig 8 - A Selected Paper on "Hardness;" Ed Widener's

program, there are two other methods of editing to chose from:

m

m

When all of the material

desired has been copied into

the word processor, the

instructor can create

additional material to suit the

specific needs of his or her

class. Here is an example of a

data sheet which could

accompany the paper on

"hardness."

Print the paper, then cut and paste as needed. You all know how to do this. - or,

Copy blocks of text and graphics to the clipboard, then paste into a word processor or

graphics program.

', ............. ,_ ............ zz_ _........... _:,.......... z-,--: ........................................................ - ........................... F:',:: ?:?:::_ :::,i_ _:_: J;N_I,_,_, ::::::::::::::::::::: _:_::_:: i..... _::_:::_:_;_ :: iiiiiii'

ili!i._ : ::7 ,i:: i::i:: :BfineU Hafdnes._:irfest DaLa:SheetZ:. :::5 : ::i::;:;_::_

::::2: : _ 7 :% :i:::!: :: ! ..::;::.: .::..::. 71;;;f i: :_ :;::: :. _::. ::::

- • • •............ _.... iiiiiii ̧ i_i!:•:: • -

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!ii ii! iii!iiiiiiili !iiiii! :ii il iiiiiiilii! !iiiiiiiii: • Iiiiiii!i! : i iit

_::k::: :_:::_::: :::::,:: .: , ....... ::::: : .:: :,,t::: :::?:_ I :1 ::.;::

•:. , ............ .. ............................... ............ .......

Fig 9 - A Locally-created Student Data Sheet

Acknowledqments and Fair Use

This CD-ROM resulted from scores of people contributing experiments and demonstrations to

the annual National Educators Workshop:Updates in Engineering Materials, Science, and

Technology (NEW:Updates). Their names are listed with their experiments on the CD-ROM, as

are the many other people and agencies who helped in this project. Cooperative funding among

460
private industry, academia, and NASA allowed for production of the CD-ROM master, with the

understanding that production and distribution would be done by a publisher. Prentice-Hall, Inc.

agreed to become the publisher.

EMSET2 is licensed for departmental use. Faculty have the right to cut and paste papers from the

CD-ROM to suit their needs. However, users should give credit to the original authors.

Getting Started

Finally, to assist in finding your way around EMSET2, you may wish to print out the Getting

Started section to use as a reference. To do this, select the GETTING STARTED button from the

Introduction Menu. After Getting Started appears, select and execute PRINT from the File Menu.

Bios

James A Jacobs

James A Jacobs is Professor of Engineering Technology at Norfolk State University. He developed the

concept and has been co-director of all the NEW:Updates. He has thirty-three years of teaching

experiences in public schools, community colleges, and universities. He has developed curricula

offerings at all three levels, including courses in material science, materials and processes technology,

engineering materials technology, and principles of manufacture.

He has industrial experience with Westinghouse Corp., Tenneco, Ford Motor Co., and completed an

intensive ten-week program with International Business Machines Manufacturing Technology Institute.

He is the author of numerous articles, books, and technical papers and presentations. Dr. Jacobs

co-authored Engineering Materials Technology, now in its third edition, and the CD-ROM set,

Experiments in Materials Science, Engineering and Technology both published by Prentice-Hall Inc. He

has been involved as consultant and director with numerous grants, seminars, and curriculum

development efforts in engineering materials, manufacturing, robotics and CAD/CAM.

Professor Jacobs is a member of the Materials Education Council of the United States, ASM

International, Society of Manufacturing Engineers, American Society for Engineering Education,

American Association of University Professors, American Ceramics Society, and is a Certified Senior

Technologist and member of the National Association for Industrial Technology.

Alfred E McKenney

Alfred E McKenney received his BS in engineering from the US Coast Guard Academy at New London,

Connecticut. After service as a line officer, he earned his MBA at Harvard Business School. He was

employed by IBM for 37 years where he specialized in the design of large manufacturing planning and

control systems.

In 1987, he was assigned by IBM on a two-year sabbatical to the School of Technology at Norfolk State

University where he taught courses in computing, tool design, mechanics, engineering material

technology, robotics, CIM, and production planning and inventory control. On retiring from IBM, he

continued teaching for two more years at Norfolk State, as well as working with Dr. Jacobs on

NEW:Update. He is now enjoying retirement and occasional independent consulting with his wife,

Evelyn.

End

461
'_'_i_ _'_//_///i_//i/1/1_,11!1/1  ̧_`__i_i_,_[_ _M_i_i®_i___ :_'_l_//i

......... H'_"HI,_"_ _'1_'_'_W"_'_'_'i_iI_1 ...................................... ,__,_ _11"_"1':'__ "_',t_'_l_it' "_1'1_- _ i_ 'lit4_i_...... "............

Welcome to MST Online

Sponsored By:

and

Norfolk State University

Question & Comments:

Jim Jacobs

Lastupdated15Sept.2000

New Items at

MST-Online

Check out our

new CD-ROM

Technology Resources:

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Technoloqv Network

and

Technology

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Site designed by

Matthew Sanders, Kamal Roz, &

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Click on ,Http://MST-Online.nsu.edu> and

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Science, & Technology

462
THE BI-SN EQUILIBRIUM

PHASE DIAGRAM

Mike Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, California 95616

Telephone: 530-752-5166

e-mail mlmeier@ucdavis.edu

463
Mike Meier

464
THE BI-SN EQUILIBRIUM PHASE DIAGRAM

Mike Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, CA 95616

USA

Key Words: equilibrium phase diagram, eutectic, thermocouple

Prerequisite Knowledge: basic understanding ofequilibriumphase diagrams, eutectic reactions, and

temperature measurement using thermocouples.

Objective: In this experiment the cooling curve method is employed to determine the transformation

temperatures for a series of Bi/Sn samples. These results are then used to construct an equilibrium

phase diagram and this phase diagram is then used to determine the composition of a sample whose

composition is unknown. This experiment also provides an introduction to digital data acquisition,

temperature measurement using thermocouples, and the use of spreadsheets in analyzing experimental

data.

Equipment and Materials: The following is a list of the types equipment that may be used in this

experiment. Please make sure you have everything you need before starting the experiment and note

exactly what type of equipment you will be using.

1. A heater capable of heating the test tubes to 400°C

2. Test tubes to hold the samples

3. Tongs for handling the hot test tubes

4. Electronic balance with 0.01 gram sensitivity

5. Weigh boats and two spoons

6. Insulated beakers (600 ml beakers filled with glass or ceramic wool)

7. Thermocouples with extension wires and reference junctions

8. DMM/scanner connected to a computer or another type of data acquisition system capable of

measuring temperature using thermocouples

9. Containers for disposing of the samples and the test tubes

10. Pure metals which are in either a granular or shot form. Note the type ofmetals used, their

manufacturers, purities, form and part numbers

Introduction: Equilibrium phase diagrams are one of the single most useful tools of a materials

scientist and engineer. As maps of the temperature ranges and solubility limits of each known phase

in the alloy system, including compounds, they are obviously useful to metal casters, heat treaters and

ceramicists and are an invaluable tool in alloy design, in the development of high-temperature

superconductors and in investigations of practically any temperature-dependent property. To one

who is familiar with how these diagrams are generated and especially to those who calculate phase

diagrams they are also representations of a number basic thermodynamic properties and in themselves

contribute to a better understanding of engineering materials.

465
There are a number of methods available for establishing a phase diagram. One, high-temperature

x-ray diffraction, allows one to make direct measurements of the changes in structure at temperature,

allowing one to study the details of the crystallographic aspects of phase transformations. Electron

diffraction, done using a transmission electron microscope, can be used to obtain similar results but

at very high magnifications, allowing one to locate and identify very small precipitates of the new

phase. But the most commonly used methods are based on thermal analysis. These include

differential scanning calorimetry (DSC) which measures the heat energy expelled or adsorbed by the

sample as it undergoes phase transformations and differential thermal analysis (DTA) which carefully

measures changes in heating or cooling behavior as compared to a reference material. Both of these

can also be used to measure fundamental thermodynamic quantities such as heat capacity, enthalpy

and entropy. Dilatometry is another thermal analysis technique which is widely used to measure the

coefficient of thermal expansion but can also determine a transformation temperature by detecting

the sudden change in volume due to the density change associated with a phase transformation. In

general, one can devise any number of bulk and microanalysis-based methods for establishing a phase

diagram by measuring any change in the sample which accompanies a phase transformation. In

practice, the results of a number of techniques published by many authors are collected and carefully

evaluated by the scientific community before they are made available for more general use and even

then you may find differences in phase diagrams for the same system (compare the phase diagrams

in references 1 and 2).

The Bi-Sn system is a classic binary eutectic system and is a good example of a system which exhibits

limited solid solubility and no intermediate compounds. Its phase diagram is very similar to that of

the well known Pb- Sn system which provides us with a number o f solders, including the 40-60 solder

which is widely used in electrical applications. The simplicity of this type of system combined with

the lower melting temperatures and lower toxicity of the Bi-Sn system makes it an ideal candidate

for classroom experiments. As a low melting alloy Bi-Sn alloys are used in temperature overload

devices and as solders in cases where the Pb-Sn solders are not suitable. For example, they may be

used in wave soldering operations where surface mount components make direct contact with the

molten metal, when the heat treatment of the metals being joined can be altered, when soldering other

low melting point alloys such as pewter and when nearby solder joints might be compromised [3].

Procedure:

Preparation: Before actually starting the experiment stop to consider the suitability and performance

of the instrumentation, certain aspects of the experimental procedure and to try to anticipate the

experimental results. This will help ensure that the experiment goes well the first time. The following

questions should get you started.

1. Sketch the equilibrium phase diagram for the Bi-Sn system. Label all phase fields and distinctive

features.

2. What are the highest and lowest transformation temperatures you expect to measure when

working with the 0, 10, 30, 50 and 100 weight percent Sn samples?

3. Estimate the value of Seebeck's coefficient for the type ofthermocouple you will be using and

for temperatures between room temperature and 300 °C?

466
. Combining questions 2 and 3, what are the lowest and highest voltages you will be measuring?

What voltage resolution will you need to be able to resolve 1 °C? What is the voltage resolution

of your system?

o When you put the thermocouple into the molten Bi/Sn mixture the thermocouple will cause the

liquid to cool, possibly solidifying some of it before you can start measuring its cooling behavior.

How do you plan to deal with this?

6. If your thermocouple reference junction is not turned on or if the battery is dead, how much error

would you expect to see in your temperature measurements?

7. Assuming you have done everything perfectly and the thermocouple is your only source of error,

how large might this temperature error be?

8. If you don't weigh out your Bi and Sn perfectly you can expect the transformation temperatures

you measure to differ from those in the established phase diagrams. How much error in weighing

do you expect to see and how do you plan to deal with this error?

9. Indicate on your sketch (question 1) the sample compositions and transformation temperatures

which will not be effected by errors in weighing out the Bi and Sn for your samples?

10. Assume your "unknown" sample has transformation temperatures of 139 and 195°C.

Referring to your equih_brium phase diagram you can see that this fits two compositions.

How would you figure out which composition it is?

This experiment presents minor hazards for all students in the laboratory. Test tubes

occasionally break so safety glasses should be worn from the moment the first specimen is heated

until the last one is cool. The specimen materials themselves pose minor hazards due to their toxicity.

These should be handled carefully and disposed ofproperly. (MSDS's for each chemical are available

in the laboratory.) The most serious hazard is the possibility of being burned by the heater and the

hot test tubes. The ceramic tubes that hold the test tubes are heated to nearly 400°C and the test

tubes are often heated to above 300°C.

Chemical Hazards There are hazards associated with the minor toxicity of Sn and Bi.

These materials should not be ingested and proper disposal methods

should be used. Refer to the MSDS for each material.

Physical Hazards Serious burns are possible. The ceramic heater tubes and the

specimens in the test tubes are heated close to 400°C. The hot parts

of the heater are labeled accordingly. Test tube clamps should be used

when handling the hot specimens.

The glass test tubes often break and spill the molten metal, especially

when being reheated to remove the thermocouple. Safety glasses and

closed toe shoes must be worn at all times.

467
Biohazards None.

Radiation Hazards None.

Protective Equipment Recommended: laboratory aprons and long pants.

Required: safety glasses or goggles. Normal eye-glasses are not

acceptable. Open toed shoes will not be allowed.

Procedure Examine the setup of the experimental equipment. Find out what each part does and how

each part works. Make sure everything is working properly and if possible try a couple of dry runs

of the experiment.

Weigh and mix the pure components to make samples ofthe specified compositions and the specified

total weight. Transfer the pure components to a test tube and then cover and shake the test tube to

thoroughly mix them. Finally, label each sample immediately to avoid mixing them up. Note that it

might not be possible to weigh out these granular materials as precisely as you'd like so make sure

you record the actual composition of each sample.

Prepare the data acquisition system in advance. It should be ready to start collecting data as soon as

the samples are transferred to the beakers and the thermocouples are plugged in. If you have time

you can run it in demo-mode to learn more about what the program can do while you colleagues are

preparing the samples.

Carefully and gently melt each sample. Be careful to not overheat them or to heat them for too long

as you might oxidize the sample or damage the test tube. On the other hand, make sure the sample

has completely melted before removing it from the heater and while you don't want to overheat the

sample you should heat it high enough above its liquidus that is doesn't start to solidify before you

can start recording the cooling behavior.

Transfer the test tubes containing the melted samples to the insulated beakers and start recording the

cooling behavior as soon as possible. Continue recording until you are sure that no additional phase

transformations are expected. (Consult an established Bi/Sn phase diagram.) When done remelt the

sample so that you can remove the thermocouple. Clean the thermocouple and dispose of the sample

properly.

Start the spreadsheet program and load the spreadsheet that has been prepared for this experiment.

This spreadsheet will help you quickly construct, display and print cooling curves, cooling rate

curves, and to determine the temperature at the start ofthe phase transformations. Use the "Import"

macro (alt-I, or the "Import" Button) to import the data, the "View" macro (alt-V) to view the

cooling curve and the "Print" macro (alt-P) to print the cooling curve. Change the scaling of the

graph as needed, and view the data on the other pages of the spreadsheet to review the temperature

and cooling rate data and to determine the temperature at various points along the cooling curves.

Results A good way to start your analysis of the results is to make a brief qualitative review of the

cooling curves. Which features do they all have in common, which ones are unique and what is the

468
significance of each of these features? Are there different "types" of cooling curves and if so what

type is the cooling curve for the "unknown" sample?

Moving on to the quantitative part of this section of the report, you will have to devise the best

method for reliably and consistently determining the transformation temperatures. Perform this

analysis, organize these results in a table and then plot these data points on an existing phase diagram.

Note the similarities and differences and note the character and the magnitude of the experimental

errors.

Once your own phase diagram is complete you should be able to determine the composition of the

"unknown" composition which was provided by your instructor. In your report you will have to

explain exactly how you did this and how much error you think there might be in your result.

Record any other interesting observations you may have made. These notes can be very helpful when

writing your report.

Discussion This experiment is straightforward and is essentially a duplication ofthe work of others.

Your discussion will probably start out comparing your phase diagram to established phase diagrams

(see figures 2 and 3) and you may even be able to say which phase diagram you'd put more stock in.

Next, you may revisit the issue of experimental error before finally reviewing how the composition

of the "unknown" was determined and telling the reader how confident he/she can be that your

determination is correct. In general, you will have to convince the reader that you have done a good

set of experiments, constructed a good equilibrium phase diagram and have demonstrated its

usefulness by determining the composition of the "unknown" sample.

Conclusion Formulate your own conclusions regarding the quality and utility of the phase diagram

you have constructed. You may have also made other observations which merit a final comment.

This is a good opportunity to make these comments.

References:

1. ASM Metals Handbook, Alloy Phase Diagrams, 10 thedition, ASM International, Metals Park,

OH, vol.3, p.106, (1992).

2. Eric Brandes, ed., Smithells Metals Reference, 6th edition, Butterworths, London, p11-139

(1983).

3. ASM Metals Handbook, Properties and Selection: Nonferrous and Special-Purpose Materials,

10thedition, ASM International, Metals Park, OH, vol.2, pp.753-757, (1992).

Bibliography:

Michael L. Meier received his B.S. in Materials Engineering from North Carolina State University

in 1979 and his M.S. (1986) and Ph.D. (1991) in Materials Science and Engineering from the

University of Califomia, Davis. After atwo-yearpost-doctoratepositionat theUniversitat ErlangenNtimberg in Erlangen, Germany he returned to UC Davis where he is the director of Materials

Science Central Facilities and teaches many of the laboratory courses.

469
Worksheet for the Binary Phase Diagram Experiment

Section Date

Lab Partners

Equipment

Balance Model

Voltmeter Model

Computer Model

Data Acquisition Software Name

Characteristics of thermoeouples used

Serial Number

Serial Number

Serial Number

Version

Raw Materials

470
0/100

10/90

20/80

30/70

40/60

50/50

60/40

70/30

80/20

90/10

100/0

Compositions are given in weight percent.

Data acquisition and storage

Compositions are given in weight percent.

471
of the Cooling Curves

0/100

10/90

20/80

30/70

40/60

50/50

60/40

70/30

80/20

90/10

100/0

Compositions are given in weight percent.

472
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473
Thermocouples

Characteristics of Thermocouples

E

K

R

Chromel

(Ni-10Cr)

Iron

Chromel

(Ni-10Cr)

Platinum13%

Rhodium

Platinum10%

Rhodium

Constantan

Constantan

Alumel

Ni-5(AI, Si)

Platinum

Platinum

-200- 900

0-750

-200-1250

0- 1450

0- 1450

T Copper Constantan -200 - 350

Reference: Omega Engineering's Temperature Handbook.

Above 0 °C:

±0.5% or

±1.7°C

Below 0°C:

±1.0% or

±1.7°C

±0.75% or

±2.2 °C

Above 0°C:

±0.75% or

±2.2 °C

Below 0°C:

±2.0% or

±2.2°C

±0.25% or

±1.5 °C

±0.25% or

±1.5 °C

Above 0°C:

±0.75% or

±I.0°C

Below 0°C:

±1.5% or

±I.0°C

Oxidizing or

inert, limited

use in vacuum

or reducing

Reducing,

vacuum, or

inert, limited

use in oxidizing

Clean oxidizing

or inert, limRed

use invacuum

orreducing

Inert or

oxidizing. Do

not use metal

protection

tubes. Avoid

contamination.

Inert or

oxidizing. Do

not use metal

protection

tubes. Avoid

contamination.

Mild oxidizing,

reducing

vacuum or

inert. Good

where moisture

is present.

Highest EMF

change per

degree.

Not

recommended

for low

temperatures.

Wide

temperature

range, most

popular

calibration

Low EMF

change, high

temperature

Low EMF

change, high

temperature

Low

temperature

and cryogenic

applications

474
Coefficients

Range .IO0°C.

IO00°C

0°C. 760°C 0°C_ 1370°C 0°C. IO00°C

Error ±0.5°C ±0.7°C _0.7°C ±0.5°C

0.104967248 -0.048868252 0.226584602 0.263632917

OoC _ 1750oc .160°C.

400°C

±I.0°C ±0.5°C

ao 0.927763167 0.100860910

al 17189.45282 19873.14503 24152.10900 179075.491 169526.5150 25727.94369

-282639.0850 -218614.5353 67233.4248 -48840341.37 -31568363.94 -767345.8295

12695339.5 11569199.78 2210340.682 1.90002x101°

a4 -448703048.6 -264917531.4 -860963914.9 -4.82704x1012

as 1.10822x10 I° 2018441314 4.83506x101° 7.62091x10 TM

-1.76807x10 n -1.18452x1012 -7.20026x1016

a 7 1.7842x10 n 1.38690x1013 3.71496x10 TM

-9.12978x1012 -6.33708x1013 -8.03104x1019

a9

8990730663 78025595.81

-1.63565x10 n -9247486589

1.88027x1014 6.97688x1011

-1.37241x1016 -2.66192x1013

6.17501x1017 3.94078x1014

-1.56105x1019

2.06132x10 _3 1.69535x102°

Reference: Hewlett-Packard's application note 290, Practical Temperature Measurements, page 8.

Standard Polynomial Form

T = a o + alx + a2x 2 + a3 x 3 ... a,x n

Nested Polynomial Form

T = a o +x(a I +x(a 2 +x(a 3 +x(a 4 +xa5))) ) (5%rder)

2000

1500

O

_- 1000

E 500

I.-

i

i

i

s

/

/

i

t

J

I

I

I

K

1

L

-500 ! _ !

-0.01 0.00 0.01 0.02 0.03 0.04 0.05 0.06

Volts

0.07

EMF-temperature characteristics of the thermocouples in the above tables.

475
Instructor's Appendix

Comments: We have used this experiment, in its current form, in our sophomore level introductory

materials science course for about 6 years. Judging from the quality of the results, the reports, and

the fact that everyone finishes in time, the experiment is almost always successful. It is also our first

group experiment of the quarter, one which requires that the students share their results, critique each

other's results and help each other perform the experiment and generate the graphs. At the end of

the class we gather around the white board, were the students have entered their data in a large table,

to review the results, make necessary corrections, etc.

This is our one experiment which requires that the students have a good idea of what the results will

be like before they start collecting data. They must study a phase diagram to find out what the

minimum temperature of the molten metal must be before removing it from the heater, and they must

decide at what temperature they can stop taking data. Having done this they monitor the cooling

curves closely looking for signs of the expected phase transformations.

We use an older computer for the data acquisition and for constructing the cooling curves. The data

acquisition program was written in QuickBASIC program and runs under DOS. It presents the

students with a series of screens where the students can view and change data acquisition parameters.

It was designed to not only collect the data but also to introduce them to the major issues in digital

data acquisition. It includes a demo-mode to allow the students and the instructor try out the

program without actually having to collect data. This feature is particularly useful when the instructor

is showing the students how to use the program.

The cooling curves are produced by a spreadsheet program (Quattro Pro 5) which has predefined

macros that help the students import, display and print the data. They can even look at the data to

determine the temperature and cooling rate at a particular time, for instance. This is the third time

they have used spreadsheets in this course and by now that have a pretty good idea of how to use

one. In this case we wanted to make the spreadsheet both useful and show them how one can use

macros to perform complicated procedures.

476
°

o-I

r_ _,_

g_ 8 _ 0

_-_ o O _

• _I _ _ o _._

_._ "_ _

_'_'_"_ _ _.

_-_i. _ _

i°_ _ _

r,.)

.__

0

0

0

r,..;

_d

0

o

0

s_

0

0

_ ° .

< <

o o

r_

a,

o oo'_

,_oo

o

477
m.

r_

ell

o

478
Test Tube Heater

Description

A suitable heater could not be purchased so I made my own. The heating elements are simply four

ceramic tubes wound with 18 gage nichrome wire and separated by ceramic fish spines to prevent

short circuits. These are put in an insulated box which is put into another box. There is a gap

between these boxes and a gap at the top to allow air to flow between them, keeping the outer box

cool. Everything is wired together and a switch and fuse holder are mounted in the outer box. To

operate it one plugs it into a variac which is set to about 30 volts. This is sufficient power to obtain

temperatures close to 400°C, hot enough to melt the sample in 5-10 minutes. A separate

thermocouple and meter are used to monitor the temperature.

Construction of the Heater

1. Make four heating elements using a procedure similar to the one below.

a. Chuck up a 0.75 inch rod in a lathe. Turn the rod at a low speed, 5 to 15 rpm.

b. Wrap about 25 feet of the nichrome wire around the rod. Keep enough tension on the wire

while winding it so that it does not uncoil when you are finished.

c. Remove the rod from the wire and slip the wire offthe rod. It should remain coiled.

d. Straighten about 10 inches of the nichrome wire. Double it back and twist it.

e. Slip the wire over the thermocouple protection tube.

£ Slip the fish spines over the wire so that the 25 revolutions of the wire are covered.

g. Straighten the about 10 inches of wire and cut the wire. Double it back and twist it.

2. Find a suitable metal enclosure. I used and older instrument cabinet/project box turned it up on

its back so that the open front panel becomes the top.

3. Make a steel liner. It should fit within the outer box with about an inch of clearance and should

have a stainless steel top that has four holes where the ceramic tube will come through.

4. Install the heating elements in the inner box, connecting them in series, and end wires coming out

of the liner. Fill the liner with ceramic wool or another suitable insulating material.

5. Install the liner in the main enclosure in such a way that minimal contact with the main enclosure

is made. Mine was mounted using four screws and four half-inch standoffs.

6. Finish the wiring, install the power switch and fuse holder. Use copper wire to connect the

heating elements to the switch and fuse holder.

7. Use a perforated metal sheet to close the bottom so that no one can be shocked yet air can flow

through.

8. Place a bit ofsoft insulating material in the bottoms ofthe ceramic tubes. This will help prevent

breakage of the test tubes.

479
Sample Results

The following figures show a sampling of results, warts and all, generated by the students.

0

to

i_

Q.

E

(D

400

350

300

250

200

150

100

50

0

Bismuth-TinSystem, 01100Bi/Sn

0 250 500 750

Time, seconds

1000 1250

I--

"1o

L)

o_

E

I400

350 300 1

250

200

150

100

50

0

0

Bismuth-TinSystem, 50/50 Bi/Sn

250 500 750

Time, seconds

1000 1250

2.0

l.51.0

I.-

480
0

O.

E

I--

400 -

350

300

250

200

150

100

50

0

Bismuth-TinSystem, 60/40 Bi/Sn

-2.0

\

\

j_

0

=

-1.5

-1.0

-0.5

250 500 750

Time, seconds

1000 1250

F300

250

_200

¢_150 L

E

_100

I50

0

Bismuth-Tin System

0 20 40 60

Weight Percent Sn

8O 100

481
Experimental Apparatus

The figures below show several scenes from the laboratory.

Heating element. Four were used in our heater. Heating station: showing the heater, variac,

temperature readout, samples and test tube

clamps.

Weighing station: showing the electronic

balance, weigh boats, bismuth and tin, and test

tubes.

Cooling Station: showing the computer, the

multimeter, and three samples cooling in their

insulated beakers.

482
RELATING ATOMIC BONDING FORCE

AND ENERGY CURVES WITH

OBSERVED MATERIAL PROPERTIES

Robert A. McCoy

Professor of Materials Engineering

Youngstown State University

Youngstown, Ohio 44555

Telephone 330-742-1736

e-mail ramccoy @cc.ysu.edu

483
Biography:

Robert A. McCoy is a Professor of Materials and

Mechanical Engineering at Youngstown State University,

Youngstown, Ohio. He has bachelor's and master's

degrees from Ohio State University and a Doctor of

Engineering degree from University of California at

Berkeley. At YSU, he teaches freshmen engineering,

mechanical engineering, manufacturing processes, and

materials engineering courses. He is also a failure analysis

consultant and a member of ASM and ASEE.

484
Relating Atomic Bonding Force and Energy Curves with

Observed Material Properties

Robert A. McCoy

Professor of Materials Engineering

Youngstown State University

Youngstown, Ohio

Key Words: Atomic bonding force, atomic bonding energy, elastic modulus, cleavage strength,

thermal expansion.

Prerequisite Knowledge: Basic knowledge of electrostatic attractive forces, the relation

between force and energy, integration and differentiation of a polynomial, and mechanical

properties determined from a tensile test.

Objective: To understand the relationships between the atomic bonding force, the atomic

bonding energy, basic mechanical properties, and thermal expansion of solids.

Equipment:

1. Tennis-ball model: two tennis balls and four wide rubber bands

2. Halfpipe model: tin can 4-inch dia. & 4-inch hr., foamed polystyrene 22x4x2 inch, small ball

3. A computer with a MS Excel

Introduction:

To gain a better understanding of the basis of the common mechanical properties of

solids, three approaches are presented to the students jointly:

1. A mathematical expression for the atomic bonding fbrce followed by integration to obtain the

potential energy expression and the use of these equations to obtain various mechanical

properties.

2. Plots oftbe fbrce and energy curves to obtain graphical soIutions.

3. Use of a tennis-ball model and a halfpipe model to illustrate physical relations.

Procedu re:

The class is assigned the following project, either to be worked out as individuals or as

small groups of two or three students each. For a K + and cr ion pair, the electrostatic attractive

force due to opposite charges and the repulsive force due to overlapping outer electron shells

depend upon the distance between centers of the ions, r, according to the equations: _

FA = 1.436 x r2 and Fa = -5.274 x 104 x r1°. For these equations, the forces are in units of

electron volts per nanometer (eV/nm) and r is the distance in nanometers (nm). The net force FN

acting on the ion pair is just the sum of the two forces. Proceed as follows:

485
a) Use MS Excel to plot the equation for FN versus r from 0.2 up to 0.6 rim. Adjust your Y-axis

scale so its range is from-6 up to 10. Quanti_ and label both coordinates.

b) Potential energy, PE, is the integral of the FN with zero potential energy defined as when the

ions are separated at infinite distance. Therefore, PE = _ FN dr. Solve the integral to obtain

an expression for PE and use MS Excel to plot this equation versus r from 0.2 up to 0.6 nrrL

Again, adjust your Y-axis scale so its range is from-6 up to 10. Quantify and label both

coordinates.

c) Graphically determine the equilibrium spacing between the two ions, ro, first using the FN

curve and then using the PE curve.

d) Mathematically solve for ro. first using the FN equation and then using the PE equation.

e) Mathematically solve for the minimum potential energy, PEo, and compare it with the value

obtained graphically. This value corresponds to the equilibrium bond energy of the ion pair

at absolute zero temperature where the ions possess zero kinetic energy.

f) Mathematically solve for the maximum force, Fmax, and compare it with the value obtained

graphically. F,_a_ correlates with the cleavage strength of the material.

g) Mathematically solve for the slope of the FN curve as it passes through zero. This slope

measures the ratio of an applied external force to the resulting increase in separation from ro.

Therefore, this slope correlates with the elastic modulus of the material, E, a measure of a

material's stiffness.

The graphical solutions for parts a, b, and c can be found in Figure 1. Answers to the

mathematical problems are:

b) PE = .[ FN dr = -1.436 x r -1+ 5.86 x 10 _ x f9

d) ro = 0.279 nm

e) PEo =-4.575 eV

f) Fmax = 9.87 eV/nm

g) E = 529 eV/rnn 2

Comments:

To help introduce the idea of the balance between the attractive force and the repulsive

force, the instructor may use two tennis balls with three or four wide rubber bands wrapped

around them, as shown in Figure 2. The tension of the rubber bands represents the attractive

atomic bond force and the resistance of the balls to being smashed corresponds to the repulsive

force resulting from the outermost electronic shells of the two ions beginning to overlap. The

equilibrium spacing between the atoms or ions, ro, corresponds to the slightly smashed together

configuration of the tennis balls pulled together by the rubber bands.

The elastic modulus of the ion pair which is found from the slope of the force curve in the

region ofro correlates with the increase in external force needed to pull the tennis balls apart a

unit distance from their equilibrium distance. The cleavage strength of the ion pair which is

found where the force curve reaches a maximum value Fm_ correlates with the external force

required to break the first rubber band. One may assume that once the first rubber band breaks,

the other rubber bands will be overloaded and break in a chain reaction.

486
The bond energy of the ion pair correlates to the amount of stored spring potential energy

of the rubber bands in their equilibrium position of holding the balls together. Thermal energy of

the ion pair correlates with the amount of their vibrational energy. The greater the temperature,

the larger the amplitude of vibration. At some temperature above absolute zero, the ion pair

vibrates between rm_x, the largest separation distance and rmin, the smallest separation distance.

The way that the kinetic energy of the ion pair is converted to potential energy and back again as

the ion pair vibrates between rm_ and rmin can be visualized by using the analogy of a ball rolling

up and down the walls of a rounded trough. Students will more readily identify with

skateboarding in a halfpipe. A halfpipe model can be constructed from a tin can and some

foamed polystyrene, as shown in Figure 3. Instead of being a half circle in cross-section, the cutopen tin can is bent into the skewed shape of the potential energy curve seen in Figure 1. When

a ball is released in this skewed halfpipe model, it rolls back and forth up to approximately equal

heights on each side, converting its kinetic energy into gravitational potential energy, analogous

to converting vibrational kinetic energy to the bonding potential energy of the ion pair.

Thermal expansion is the result of combining the larger amplitude of vibration at higher

temperatures along with the nonsymmetricai shape of the energy curve. Referring to the halfpipe

model, the higher the temperature, the higher the ball rolls up on each side of the trough. If it is

assumed that the average spacing between atoms at some particular temperature is given by

1⁄2(rm, x + r_), one can see that as the temperature increases, this average spacing increases above

the equilibrium spacing due to the nonsymmetrical nature of the energy curve, as shown by the

dashed line in Figure 1.

Following the presentation of the relations discussed above, the instructor should now ask

the students what are the effects of increasing bond strength on the various observed material

properties. These effects can be observed by having the students repeat the steps in the

procedure section, only this time double the magnitude of FA so that FA = 2.872 x r 2. When

plotting this revised equation, the students need to change the range of the Y-axis, as seen in

Figure 4. Specifically the students should observe that as bond strength increases, the FN curve

shills up and to the left whereas the PE curve dips lower and to the left and becomes more

symmetrical. The dashed lines shown in Figure 4 indicate the average atomic spacing as the

temperature increases. These observations should Mlow the students to deduce that as bond

strength increases,

a) the equilibrium spacing, ro, decreases

b) the elastic modulus, E, increases

c) the cleavage strength, Fm_, increases

d) both the equilibrium bond strength, PEo, and the melting point increase

e) the thermal expansion effect decreases

References:

1. W. CaUister, Materials Science & Engineering: An ]introduction, John Wiley & Sons (2000).

487
488

\

\

d

c5

d

¢-

¢,-

°_

._o

E

m

o

o

c_

c_
Figure 2. Tennis-ball Model

Figure 3. Halfpipe model

489
W

"O

C

O

m

£

cO

I.,.,

C

._w

D

1=

O

ff

r.,,

n

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C

U.I

o

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i,.L

.m

lUL

LO O _r) o

04 04 _

f

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(mU/Ae) eoJo...4_.eN

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t

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04

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c.-

0

£

0

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®

!

490
THE BRAGG BUBBLE RAFT FILM

Mike Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, California 95616

Telephone: 530-752-5166

e-mail mlmeier@ucdavis.edu

491
Biography:

Michael L. Meier received his B.S. in Materials Engineering from North Carolina State University

in 1979 and his M.S. (1986) and Ph.D. (1991) in Materials Science and Engineering from the

University of California, Davisl After atwo-year post-doctorate position at the Universit_it ErlangenNttrnberg in Erlangen, Germany he returned to UC Davis where he is the director of Materials

Science Central Facilities and teaches many of the laboratory courses.

492
THE BRAGG BUBBLE RAFT FILM

Mike Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, CA 95616

USA

Key Words: crystalline lattice, plastic deformation, dislocations, slip, grain boundary, tilt boundary,

recrystallization, vacancies, bubble raft

Prerequisite Knowledge: Familiarity with the nature of the crystalline lattice, dislocations and their

role in plastic deformation, and mechanisms of dislocation motion and interaction with other lattice

defects.

Objective: The objective here is to show instructors a film that they would surely find useful in their

mechanical properties courses, if they could find it.

Equipment and Materials: You'll need either a film projector or a VCR, depending on the format

of your copy.

Introduction:

The title of the film is Experiments with the Bubble Model of a Metal Structure. The authors,

narrators and actors are Sir Lawrence Bragg, W.M. Lomer and J.F. Nye, the film was made in 1954,

and it was produced by N.S. MacQueen. I have been unable to determine who is currently

distributing this film, but at one time it was distributed by MacQueen Film Organisation, Kent

England, and in the mid-1980's it was distributed in parts by Ealing Film-Loops, Cambridge,

Massachuttes. Segments of this film have also been used in John Russ's CD [1]. A search of the

web has not turned up any new information regarding the availability of this film, but responses to

my queries in the internet discussion groups alt.metallurgy and alt.materials indicate that the people

who have seen the film really admired it, and at least one other copy can be found a the University

of Pennsylvania in Philadelphia, PA. My web search did turn up a number of sites describing the

use of the bubble raft model in the classroom. It seems that the idea of the bubble raft model of the

structure and deformation of a metal is much better known that this film.

The film starts by introducing the concept of a metal as atoms in regular patterns, the crystalline

lattice. It then introduces the bubble raft model by stating that the forces that hold bubbles together

are very similar to those which hold atoms together, and that one can construct a bubble raft model

using a soap solution and a carefully controlled jet of air. The film shows the raft, representing a

perfect lattice, then goes on to show grains and grain boundaries until it gets to the main point, the

role of dislocations in plastic deformation. Several frames from this film are shown at the end of this

paper.

Procedure:

493
The one time I showed this film in class I had just spent two weeks describing dislocations, strain

fields around dislocations, interactions between dislocations, vacancies and solute atoms, the

formation of tilt boundaries, the mobility ofsubgrain boundaries, etc. I sensed that at the end of these

lecture the students had heard about all of these things, that it all seemed logical enough, but were

still not real to them. After the film was over their faces had changed. Dislocations were real, and

they did all of the things I had described, sketched on the black board, etc. They were really

impressed by how nimble the dislocations were. They could move so quickly, and yet the bubbles

themselves hardly moved at all, unless one watched many dislocations moving for a period of time.

The theory of dislocations really could explain plastic deformation!

Comments:

I intend to continue my search for information (historical and availability) on this film and willpost

my findings on our web site at www.matsci.ucdavis.edu.

References:

1. J.Russ, Materials Science: A Multimedia Approach, PWS Publishing Co., (1996).

494
Figure 1 Perfect crystalline lattice. Figure 2 Grains and grain boundaries.

Figure 3 An edge dislocation. Figure 4 The Burger's circuit.

Figure 5 Interactions between dislocations. Figure 6 Low angle boundary.

495
Figure 7 Subgrain boundary migration. Figure 8 Grain boundary shear.

Figure 9 Grain boundary sliding and

migration.

Figure 10 Plastic deformation.

Figure 11 Three-dimensional bubble raft. Figure 12 The End.

496
GALVANOSTATIC POLARIZATION CURVES

FOR TEACHING PURPOSES PART III

Carlos E. Umana

Department of Materials

School of Mechanical Engineering

University of Costa Rica

San Jose, Costa Rica

Telephone: 506-207-4548

e-mail caruma @terraba.fing.ucr.ac.cr

497
498
GALVANOSTATIC POLARIZATION CURVES FOR TEACHING PURPOSES

PART IH

Carlos E. Umafia

Departamento de Materiales

Escuela de Ingenieria Mec_inica

Universidad de Costa Rica

San Jos6, Costa Rica

KEY WORDS: Equilibrium potential, exchange current density, cathodic protection by external

power supply.

PREREQUISITE KNOWLEDGE: A complete understanding of the theory and experimental

work involved in parts I and II of this experiment (Ref. 1 and Ref.2).

OBJECTIVES:

1. Explore the meaning of exchange current density.

2. Introduce the concept of Overpotential for Negligible Internal Current (OPNIC).

INTRODUCTION:

The first part of this experiment was presented at the NEW:Update 98 and the second part at the

NEW:Update 99. All the experimental work was performed in both first and second stages. This

third last part consists of an analysis that will be combined with the experimental results of part II, in

order to complete an experimental and analytical presentation of all the basic parameters associated

with experimental applied current curves and polarization diagrams.

As it was described in reference 1, the working electrode can be represented as one anodic area and

one cathodic area, which are the result of gathering together all the small anodic and cathodic areas

distributed within the working electrode surface. Figure 1 shows a schematic polarization diagram

and a working electrode at corrosion potential and under either anodic or cathodic overpotential. The

total current is the sum of both the applied and the internal current. As the total current increases the

internal current approaches zero and the question is, at what overpotencial will the internal current be

negligible? The following suggestions have been proposed in the literature (Re£3) to define this

overpotential, which in this work will be known as Overpotential for Negligible Internal Current

(opec):

1. The overpotencial is defmed by the chemical equilibrium potential.

2. Apply an overpotential in between 100 and 300 mv.

3. For cathodic protection of steel, field experience defines an overpotential of -573 mv (versus

SCE) in both seawater and soil.

499
In a solution as the one used in this experiment (deaerated 20 g/1NaC1, pH_ 7), the anodic and the

cathodic reactions and the corresponding chemical equilibrium potentials versus SCE are as follows

(Ref.4):

Fe ---> Fe 2+ + 2e- E o = -688 mv

2H20 + 2e- ---> 20H + H 2 E o =-654mv(pH_7)

The corrosion potential obtained in part II was Ec_r = -500 mv. Just as it is always observed in the

corrosion literature, in this case the anodic equilibrium potential is also under the corrosion potential

with a cathodic overpotential of-188 mv = - 688 mv - (-500 mv). However, and contrary to the

common behavior, the cathodic equilibrium potential is also under the corrosion potential. This

means that the corresponding overpotential is also negative and the exchange current density is larger

than the corrosion current density. Two important conclusions can be derived from this result:

1. The chemical equilibrium potential does not define an OPNIC and therefore the exchange

current density cannot be used as the limiting point of an anodic or cathodic reaction•

2. The exchange current density is more an electrochemical constant than a corrosion parameter of

practical use.

The second approach is based on the fact that it has been observed that the OPNIC is usually around

100 to 300 mv. However this observation is useful only as a verification in connection with a more

precise procedure.

The third suggestion gives a specific potential, which is equivalent to a cathodic overpotential of

-273 mv for an E_o= = -500 mv. This value is within the overpotential range given before, but it

should be remembered that this only applies for aerated solutions. Therefore in this experiment this

overpotential can be used only as a reference.

INTERNAL AND TOTAL CURRENT DENSITY RELATION APPROACtt

In this work a more rational approach is proposed to define an OPNIC value. It consists in comparing

the internal current to the total current by using a prefix ratio "r" for an anodic or cathodic

overpotential. The anodic coefficient ra is expressed as:

la,int

ra----

l a, tot

(1)

Where:

The anodic internal current density is given by i a ,int = lcorr e

2.3£

(2)

500
and the anodic total current density is given by l a ,tot : I corr

2.3,_

12

(3)

Similarly the cathodic coefficient r c is expressed as:

°

lc,int

rc=--

l c ,tot

(4)

where

The cathodic internal current density is given by

• •

lc,int "- lcorr

2.36

C

(5)

and the cathodic total current density is given by

• °

l c ,to t -- l corr

2.36

C

(6)

Substituting current densities in equation (1) and (4) results in the expressions

oc' a

(7)

(8)

Which are the overpotentials for a given r ratio. It is easy to observe that s a = -6 c if ra = r c .

501
RESULTS

In this case it could be reasonable to accept that the internal current is negligible when it becomes

one hundred times smaller than the corresponding total current, in other words r =1/100. On the other

hand the Tafel slopes obtained in part II are 13o= -512 my_/decade and 13a= 176 mv / decade

(1 decade = 1cycle). By substituting these values in equation 7 and 8 the following OPNIC values are

obtained:

ca=262mv and 6 c=-262mv

This overpotential is very close to the practical value of- 273 mv given for cathodic protection.

Equations (2) and (5) give the corresponding negligible internal current densities using the

experimental result i_o= = 19 gA/cm 2 obtained in Part II.

ia,in t = 5,86pA/cm 2 and ic,int = 0.62 t.z,'t/cm 2

Figure 2 shows the complete polarization diagram including the anodic and cathodic OPNIC and

NIC values, which are the coordinates of the terminal points of the polarization lines.

REFERENCES:

1. Umafia, Carlos E.: Galvanostatic Polarization Curves for Teaching Purposes, NASA/CP-1999-

209549, National Educators' Workshop: Update 98, 1999.

2. Umafia, Carlos E.: Galvanostatic Polarization Curves for Teaching Purposes Part 1I, NASA/CP2_000-210325), National Educators' Workshop: Update 99, 2000

3. Jones, Denny A.: Analysis of Cathodic Protection Criteria, Corrosion, Vol. 28, N °11, November

1972.

4. Jones, Denny A.: Principles and Prevention of Corrosion, Second edition, Prentice Hall, Inc.,

1996.

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STRESS CONCENTRATION

EFFECTS IN A THIN SHEET

Aaron S. Blicblau

Senior Lecturer, Materials Engineering

School of Engineering and Science

Swinburne University of Technology

P. O. Box 218 Hawthorn

Victoria, Australia 3122

Telephone:

e-mail ABlicblau @ groupwise.swin.edu.au

5O5
Aaron S.Blicblau

/

PRESENTED BY Harvey Abramowitz

506
Stress Concentration Effects in a Thin Sheet

Aaron S. Blicblau

Swinburne University of Technology

Hawthorn, Victoria,

Australia, 3122

Keywords: Stress concentration, thin sheet, round hole, geometry factor

Prerequisite Knowledge: Basic knowledge of linear elastic stress and strain, using Hooke's

law. Conversion of deformation measurement to strain values,

conversion of load data to stress values.

Objective: To demonstrate the effect of a hole on the stress concentration in a

sheet of rubber.

Equipment and Materials:

.

.

3.

4.

One rubber sheet approximately 450mm x 200ram x 6 mm with a 30 mm round hole in

the centre.

On the rubber sheet (see Figure 1) is a square grid with ruled vertical and horizontal lines,

one centimetre apart, centred on the round hole. This grid is four cm high and 18 cm

wide.

Near the top of the rubber sheet is a ruled square with sides 10 cm. with no holes.

Four individual weights each of 100 kN.

One metal frame from which to hang the rubber sheet.

One centimetre-millimetre graduated ruler.

In_oduction

In most engineering designs elastic properties of materials form the basis of design. These

properties include stress (load/area), Young's modulus (stress/strain), and Poisson's ratio (strain

in horizontal direction divided by strain in vertical direction). In this experiment the elastic

behaviour of materials and the effect of a discontinuity (a circular hole in a plate) are to be

investigated. A rubber sheet is used, since the low elastic modulus of rubber compared with

metals allows greater deformation for a given load; it should be noted that there is a significant

difference between rubber and metals in that the stress-strain relationship for rubber may be nonlinear in the elastic range.

5O7
Theory

The intensity of force or stress "6" (sigma), is defined as the force acting on unit area - (i.e. it is

the same as pressure). Because engineers are interested in initial shape, nominal or engineering

stress (force divided by initial cross sectional area) rather than actual stress (force divided by

actual cross sectional area) is considered because it is easier to measure.

Consider the rubber sheet for this experiment (Figure la). Ifa force acts on it, elongation of the

sheet occurs. So that the original length of the sheet does not have to be specified each time, the

fractional change,( change in original length/original length) in a dimension, or strain "e"

(epsilon) is commonly used, i.e. Force o_extension (Hooke's Law) as shown schematically in

Figure 2.

The constant of proportionality is the

Stress, _ gradient of the graph, "E", which is

called the elastic modulus or

Young's modulus.

Therefore

/e E = G/e

Strain

Figure 2. Schematic representation of a typical stress strain curve.

Procedure Part A

Measure and record the cross sectional area of the whole rubber sheet for calculation of

nominal stresses, i.e., width and thickness of the sheet.

For each measurement required, fill in the data in Table 1.

1. Measure and record the dimensions of the top ruled square on the surface of the rubber

sheet (i.e. shown in Figure lb and is the ruled square away from the central hole). Note

these are the original dimensions of the rubber square in the X and Y directions.

2. Load the sheet with 100 N, 200 N, 300 N and 400 N, one load at a time.

3. For each load, measure and record the change in length vertically (Y direction) and

horizontally (X direction) produced in the top square, and write these values in Table 1.

4. Calculate the strains produced in the horizontal and vertical directions.

5. Plot _y as a function of the vertical strain (er) and horizontal strain (e,,), on Figure 3.

5O8
Report - Part A.

The cross sectional area of the rubber sheet perpendicular to Y axis:

A (cross section area) = (width x thickness) = 0.5ram x 150mm = 750 (mlTl 2)

Table 1. Measurements and calculations of strain and stress in the square section.

Applied

Load

v x _ _ ey ex ay

Vertical

mnl

Horizontal

111111

Change in

Y

dimension

Change in

X

dimension

(strain) (strain) (stress

MPa)

o N 100 100 0 0 0 0 0

100 N 105 97 5 3 0.05 0.03 0.13

200 N 110 95 10 5 0.10 0.05 0.26

300 N 118 93 18 7 0.18 0.07 0.4

400 N 125 90 25 10 0.25 0.10 0.53

Ov(MPa)

0.5

...................... _ .................. _ .................. _ ............................... _ .............. _ DILl .............. ; ................. _ .................. _ .................. ; .............. _ ..........

...................... 'ij.................. !i.................. [i................. !i............ !i_i .................. o;.4o._ o.2........ ]j................. _!i................. !t............. _................. !t..............

...................... ,.................. i................. i.............. 1111111111111111111111 ............................................iiiiiiiiiiiiiiiiiiiiiiiiiiii..............

(ex) 0.2 0.1 0._ 0.2 %)

Figure 3. Stress (_y as a function of the vertical strain (ey) and horizontal strain (ex).

509
Procedure Part B

On the rubber sheet, surrounding the hole, a rectangle containing 1 cm square grids has been

ruled. This is to enable the strain to be determined at various positions away from the hole (see

Figure lb).

For each measurement required, fill in the data in Table 2.

1. For a load of 300 N, measure and record in Table 2 the change in vertical distances between

adjacent points on the grid around the hole between a and b (i.e. between points 1 and 1", 2

and 2*, 3 and 3*, 4 and 4*, 5 and 5* 6 and 6* and 7 and 7*, as shown in Figures lb and 3).

2. Using the results from part A in Table 1, calculate E, the MODULUS at 300N.

3. Calculate the strains at each position.

4. Calculate the stress at each position.

5. Plot a graph of stresses in the Y direction _y versus horizontal position ( X-X* ) measured

on the rubber sheet containing the hole, on Figure 4.

Report - Part B.

The modulus at 300N, is: E = ay/_ (at 300 N) = 0.4/0.18=2.22 MPa

Table 2 Measurements and stresses at various positions away from the hole on the rubber

sheet.

Item

Initial distance (Yo)

between points

(at 0 N)

Final distance (Yu)

between points

(at 300 N)

strain

YU -- YO

_o : at3OO N at ON

1-1"

2O

32

2-2"

2O

28

Position of Measurement

3-3*

2O

26.5

4-4"

2O

26

5-5*

2O

25

6-6"

2O

25

_:-'ii  ̧ ̧ ̧ ̧7ii:ii:i

Y

o atON

stress

(_ y -_ EE y

1.33 0.88 0.73 0.66 0.55 0.55

7-7"

2O

25

0.5

510
Stress

MPa

1.25

1.0

0.75

0.5

0.25

0

o

2 3 4 5 6

POSITION OF MEASUREMENT

Figure 4. Stress at various horizontal positions away from the hole.

)

7

1. Sketch below (on Figure 5) the position in the rubber grid subjected to the greatest tensile

stress. Mark this position as "G".

2. Sketch below (on Figure 5) the position in the rubber grid subjected to the least

tensile stress. Mark this position as "L".

3. Sketch below (on Figure 5) the position subjected to the greatest compressive stress.

Mark this position as "C".

L C L

°0°

C

L L

Figure 5. Positions on the rubber grid subjected to the greatest(G) and least(L) tensile stress and

the greatest compressive (C) stress at a load of 300 N.

511
The ratio of stresses, and thus the stress concentration fhctor K

(Catlister; 2000, p192):

where:

is given algebraically as

Kt is the stress concentration factor

Crmis the maximum stress at the crack tip

O'ois the magnitude of the nominal applied stress

a is the represents the length of a surface crack

jot is the radius of curvature of the crack tip

Note that a and jot are difficult to measure experimentally, so that Kt

is evaluated numerically from the stresses calculated in Table 2 as:

Kt= Crm i.e. 1,33/0.5 = 2.66

ao

List three common stress concentrators:

holes, flaws, and cracks or corners

References:

Callister,W.D.Jr, Materials Science and Engineering, Wiley, NY, 2000, 5 th ed. pp. 191-193.

Biography:

Aaron Blicblau received his B.E.(Hons) in Materials Engineering from Monash University, Australia in

1974. He then pursued postgraduate studies at the University of New South Wales in the area of fracture

mechanics of natural composite materials. During 1993 he was a Visiting Scientist in the Department of

Education in Science and Technology at the Technion, Israel Institute of Technology. Aaron is currently

a Senior lecturer in the area of materials engineering and has most recently been coordinator of f'mal year

engineering projects for mechanical and manufacturing engineering students. Correspondence:

Swinbume University of Technology, School of Engineering and Science, PO Box 218, Hawthorn,

Victoria, Australia 3122.

512
undeformed

square

Figure 1 a. Experimental set-up

showing suspended rubber sheet

with central hole and upper ruled

,_flllgre.

Figure lb. Close-up of rubber

sheet showing top square

section and grid surrounding

central hole.

Figure 3.Measuring the extension of the gridlines in the

vertical direction.

513
514
CURRENT AND FUTURE USE OF STRUCTURAL

AUTOMOTIVE COMPOSITE MATERIALS

Tom Dearlove

and

Ed Hagerman

GM R&D Center

MC: 480-106-316

30500 Mound Road

Warren, Michigan 48090-9055

Telephone: 810-986-1267

e-mail thomas.j.dearlove @gm.com

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UNDERGRADUATE EDUCATION IN

COMPOSITE MATERIALS

James M. Whitney

Department of Civil and Environmental Engineering

and Engineering Mechanics

University of Dayton

300 College Park

Dayton, Ohio 45469-0243

Telephone: 937-229-3847

e-mail James.Whitney @notes.udayton.edu

549
James M. Whitney

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Mechanics of Composite Materials

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579
580
WORKSHOP PRESENTATIONS

Teaching With Simulation .......................... 583

Tom Carlisle - Sinclair Industrial Engineering Technology Department

Programmable Powder Preform Process (P4) Workshop:

Developing Low Cost Composites .................... 591

Mike Melton, Scott Reeve, Correen Schneider - National Composite Center

Vacuum Assisted Resin Transfer Molding (VARTM)

for Fabrication of Bridge Decks and Other Structural

Applications ...................................... 599

Presented by Mike Mutton - National Composite Center

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Teaching With Simulation

The Sinclair

Industrial Engineering Technology

_mn °Department

Welcomes

al Educators' Workshop

Attendees

Teaching With Simulation

Teaching With Simulation

Copy Right_) 2000

By Thomas M. Carlisle

All Right Reserved

Reproduction, modification or any other use of this

material is prohibited with out permission of the

attthor

Agenda

-) Inlroduction

•-}Defined Our Instructional Methods

-)Curriculum Development Methods

-)Use Of Power Point __

-)Established Standard Products --_--_:!:'_

-)Equipment & Lab Development

-)Use Of Virtual Simulation

-)Results To Date

-)The Future .

Tom_i_e l_¢_ax_

Introduction

-'l, Reasons For Using Simulation

-)Desire to change to Activity Based Teaching

-)Simulation is a more effective way for faculty to"

teach and for students to learn

-)increas.ed student interest and participation

-)Improved correlation between curriculum and the

"Real World"

Tom eln_.l_ le/_g-aooo 6

Defined Our

Instructional Methods

•-)Activity Based Instruction

-) Some lecture with increased structured experiences,

via simulation, in the classroom and lab

•")Use of Power Point

-) Includes use of photographs, sound, graphs, charts,

illustrations, clip art and animation

-) This became the department standard

584
Defined Our

Instructional Methods

-_Lab Flexibility

-_ Almost all the equipment in the lET lab can be easily

moved

-._ The lab equipment can be quickly rearranged to set

up almost any type of production system or situation

-11,Several different types of equipment are available

-'_ Use of Creform building materials provides ability to

quickly and cheaply design and build new equipment

and work places

Defined Our

Instructional Methods

")MS Office installed on all full time faculty

computers

•@Part time faculty using Power Point files or

developing Power Point coOrses also have Power

Point installed on their home computers

-_ZIP drives also installed on all full time faculty

computers and loaned to part time faculty

•-)Training provided

Defined Our

Instructional Methods

-_Computer Carts designed and built for classroom

and lab use

")Computer Cart Specifics

'-)Contained in a cabinet built with plywood and

Creform

,'_Computer with the normal floppy, CD-ROM & hard

drives

"-),Monitor

-_Video projector

T_ elelhl, io/_d_o0 1o

Defined Our

Instructional Methods

-_ZIP drive

-_VCR

•-)Sound system

-_ Printer

_Telephoue jack to allow Intemet access

-).Extension cord with a take-up reel

•").On a heavy duty frame with casters

•-)Sized to fit through the standard sized classroom

door

Defined Our

Instructional Methods

"_All locks opened by one key

_Master power switch

-_Slots in the cabinct allow access to the drives without

opening the doors

Established Standard Products

--) Often students have trouble relating what they

learned in one class to what they are learning in

their current courses and products are needed to

support simulation

•"_ Two products are used to address these problems

--)"Wagons-R-Us" _

•_Robotic Gripper

T_a C_tlglJ

585
Established Standard Products

"Wagons -R- Us'"

•") A product line of six small simple, scale wagons

and one tractor has

"_ Made from KNE'X

•-) Used to teach initial manufacturing and IET

principles

-_ Used in several courses to provide related

activities and tie the courses together

Established Standard Products

") A complete set of manufacturing documentation

is available as an aid to developing simulations

@Part numbering, sub-assembly and product

identification system !

@Processing plans and routings

@Sequence diagrams

@Sales and shop order forms

@Bills of Material

Tomca_id¢ 1_00 15

Established Standard Products

@.)Short company his_ry

@')Tooling, material handing equipment and CNC

machining fixtures and CNC programs

@Simulated shop floor layout and warehouse

=_ Wagons -R- Us is used in the lower level courses

to introduce manufacturing and Industrial

Engineering concepts

"_ Used for providing related simulation

experiellces

T_ Onli_le 1_2_000 16

Established Standard Products

•-) Students take simulations and projects completed

in one course and expand upon them in the next

-_ Wagons -R- Us data used in course development

as a means to provide consistent instruction and

course examples

W -R- U is built into the Power Point notes

Established Standard Products

Robotic Gripper

•-) Developed as part of an NSF grant peoject

")Replaces W-R-U in higher level courses

•"_ Provides a more complex and realistic product to

teach with

Established Standard Products

-l, Manufacturing and product data is available

@Part @AutoCad numbers drawings .__,--_ "

@Process plans and routmgs__¢_

@Bill @Material of Material specifications _ --__._,,..._

Tom C_di_o I_2/_000 __4

586
Equipment & Lab Development

•"_ Extensive planning and development has gone

into the lET Lab

-]_ Bob Hazel is the KEY to our lab development

Equipment & Lab Development

•'_ Almost evewthing in the lab can be easily

reposifioned

Rapid changes in equipment layout possible

-l, Almost any manufacturing operation, from simple to

complex, can be quickly simulated _ [

Equipment & Lab Development

"_ Rapid changes" are layout possible

Equipment & Lab Development

•"_ Almost any mamffacturing operation, from

simple to complex, can be quickly simulated

Tona

Equipment & Lab Development

Special equipment has been designed and built to

simulate more complex and expensive

production machinery

Automated machinery processes

•-_ Manual machinery processes

•.]kThese cost a small fraction of the cost of full size

equipment

,_ Sized to support both KNE'X and the gripper

-) Very flexible to use

"remcl_a_ 1o/a_r_oo .'_

& Lab Development

587
.... Equipment .& Lab Development

-If,Use of KNE'X, the C_n-ipper and Creform allow

students to design, test, evaluate and demonstrate

their own workplaces, tooling and manufacturing

plans

-]_Many IET courses require this as a student team

roB/

Equipment & Lab Development

-'_ Other equipment provided

-_ Belt and skate wheel

-_ Band saw

-_ Drill press

•_ Cainder

.-_ Hand tools

"_ Tool hangers

.,_ Tooling fixtures and packaging

Equipment & Lab Development

"_A screen and white board is provided

•") Small CNC machines allow us to tie machine

tools into student designed processes

-'_ In the IET lab students can be provided with

simulated but realistic problems and assignments

Tm earlM*

Use Of Virtual Simulation

-)Using ProModel simulation software we also

combine physical and computer simulation

.... z _ :--Cy: ¢,

Use Of Virtual Simulation

").Using the products, materials and equipment

descn'bed a manufacturing system can be set up

Use Of Virtual Simulation

-_ Tim students collect information about it and

program and run a computer simulation

588
Use Of Virtual Simulation

"_Then we run the physical simulation and

compare it to the computer run results

Use Of Virtual Simulation

Or, we can go in the opposite direction and

design a process, simulate an then build it

Use Of Virtual Simulation

-) An example of this will be shown after this

presentation

Results To Date

"_ To date almost all IET courses have been

impacted by the simulation methods presented

•-_ Curriculum improvement is an ongoing activity

"_ Use of W-R-U and the Robotic Gripper has

increased student ability to see the integrated

nature of their knowledge

Results To Date

"_ Use of ProModel and the products, materials and

equipment described enable us to use simulation

ha many effective ways in many courses

"]_Use of Power Point has improved class quality

and consistency

"_ Student interest and participation has improved

•-) This is just a FUN way to teach and learn

The Future

"_Efforts will continue

All courses will be continuously improved

•_ Additional simulations will, where appropriate, be

included

589
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Form Approved REPORT DOCUMENTATION PAGE OMB NO. 0704-0188

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I

August 2001 Conference Publication

4. TITLE AND SUBTITLE 5. FUNDING NUMBERS

National Educators' Workshop:Update 2000

Standard Experiments in Engineering, Materials Science, and Technology WU 706-17-41-22

6. AUTHOR(S)

Compiled by Edwin J. Prior, James E. Gardner, James A. Jacobs, and

Louis A. Luedtke

7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION

REPORT NUMBER

NASA Langley Research Center L-18105

Hampton, VA 23681-2199

9. SPONSORING/MONITORING AGENCY NAME(S) AND ADDRESS(ES) [10. SPONSORING/MONITORING

National Aeronautics and Space Administration, Washington, DC 20546-0001; Norfolk State AGENCY REPORT NUMBER

University, Norfolk, VA 23504; National Composite Center, Kettering, OH 45420; National

Institute of Standards and Technology, Gaithersburg, MD 20899; Department of Energy, Oak NASA/CP-2001-211029

Ridge, TN 37831; Wright-Patterson Air Force Base, OH 45433; University of Dayton, Dayton,

OH 45469; Gateway Coalition, Drexel University, Philadelphia, PA 19104

11. SUPPLEMENTARY NOTES

Prior and Gardner: Langley Research Center, Hampton, VA; Jacobs: Norfolk State University, Norfolk, VA;

Luedtke: National Composite Center, Kettering, OH

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12b. DISTRIBUTION CODE

13. ABSTRACT (Maximum 200 words)

This document contains a collection of experiments presented and demonstrated at the National Educators'

Workshop:Update 2000 held in Dayton and Kettering, Ohio, October 29-November 1, 2000.

14. SUBJECT TERMS

Materials; Experiments; Education

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