NASA / CP-1999-209549

/

" _9

National Educators' Workshop: Update 98

Standard Experiments in Engineering, Materials Science,

and Technology

Compiled by

Ginger L. F. Arrington and James E. Gardner

Langley Research Center, Hampton, Virginia

James A. Jacobs

Norfolk State University, Norfolk, Virginia

Karl J. Swyler

Brookhaven National Laboratory, Upton, New York

Leonard W. Fine

Columbia University, New York, New York

October 1999
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NASA / CP- 1999-209549

National Educators' Workshop: Update 98

Standard Experiments

and Technology

in Engineering, Materials Science,

Compiled by

Ginger L. F. Arrington and lames E. Gardner

Langley Research Center, Hampton, ViJxinia

James A. Jacobs

Norfolk State University, Nolfolk, Vitxinia

Karl J. Swyler

Brookhaven National Laboratory, Upton, New York

Leonard W. Fine

Columbia University, New York, New York

Proceedings of a workshop sponsored jointly by the National Aeronautics and Space

Administration, Washington, DC; Norfolk State University, Norfolk, Virginia;

the National Institute of Standards and Technology, Gaithersburg, Maryland;

Brookhaven National Laboratory, Upton, New York; the International Council for

Materials Education, Columbia University, New York, New York; and Gateway Coalition,

State University of New York at Stony Brook, New York

and held in

Upton, New York

November 1-4, 1998

National Aeronautics and

Space Administration

Langley Research Center

Hampton, Virginia 23681-2199

October 1999
I 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 the following:

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) 487-4650
PREFACE

NEW:Update 98, hosted by Brookhaven National Laboratory, Columbia University and the

University of Stony Brook in New York, was held on November 1 - 4, 1998.

The 13th Annual NEW:Update built on themes, activities and presentations based on extensive

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

materials education. About 100 participants witnessed demonstrations of experiments, discussed

issues of materials science and engineering (MS&E) with people from education, industry,

government, 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.

As in past years we were fortunate to have excellent support from our hosts. Karl Swyler, Leonard

Fine, and Chris Bemdt helped to coordinate the many scientist, engineers, professors and other

staff, by providing funding, opening their facilities, developing presentations and activities.

NEW:Update 98 participants saw the demonstration of about forty experiments and aided in

evaluating them. We also heard updating information relating to materials science, engineering

and technology presented at mini plenary sessions.

The experiments in this publication can serve as a valuable guide 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.

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.

NEW:Update 98 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:Update 98,

with its diversity of faculty, industry, and government MSE participants, served as a forum for

lU
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 Experiments in Materials Science, Engineering & Technology, (EMSET)

CD-ROM with all 213 experiments from the first decade of 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 demo 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.

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

Special thanks goes to those on our national organizing committee, management team, hosts,

sponsors, and especially those of you have developed and shared your ideas for experiments,

demonstrations, and novel approaches to learning. All of us who participated in the workshop

appreciated the excellent coordination of activities by Jim Gardner, Diana LaClaire, and Ginger

Arrington.

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

Workshop Co-Directors NASA LaRC Coordinators

James A. Jacobs

Workshop Co-chairperson

Norfolk State University

James E. Gardner and Ginger L. F. Arrington

National Aeronautics and Space Administration

Langley Research Center

Karl J. Swyler

Workshop Co-chairperson

Brookhaven National Laboratory

Leonard W. Fine

Workshop Co-chairperson

Department of Chemistry

Columbia University

Assistant Director

Diana P. LaClaire

Norfolk State University

Committee Members

Christopher C. Bemdt

Dept. of Materials Science and Engineering

State University of NY - Stony Brook

Robert Berrettini

International Council for Materials Education

Paul W. Brown

International Council for Materials Education

S. Raj Chaudhury

Norfolk State University

James A. Clum

State University of NY - Binghamton

Morton B. Friedman

School of Engineering

Columbia University

Kenneth L. Jewett

National Institute of Standards & Technology

Thomas F. Kilduff

Thomas Nelson Community College

Socky Lugo

Columbia University

James V. Masi

Western New England College

Alfred E. McKenney

IBM Corporation, Retired

Heidi Ries

NorfolkState University

Thomas G. Stoebe

University of Washington

Laura L. Sullivan

American Society for Engineering Education

V
Acknowledgments

We greatly appreciate the support provided by these organizations:

The American Society for Engineering Education

The ASM Foundation

The International Council for Materials Education

vi
CONTENTS

PREFACE

° °°°°°'° °° ° "*'" °''°°'" °* °" "'°*° ° °°" °*" ° ° °° ° °o -°-° °°° ° ° °°°°°.. °. iii

MANAGEMENT TEAM °'°°°°'°'°--°- °. *° °*° °o°°o°°°°o_°°.o°...°. °°°°° o.°. V

ACKNOWLEDGMENTS

°°°'°**°°°°°" "°'° "°°°°'°°°° "°" °°°°°°.-° .... ° ° ° ° ° ° . . vi

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

LISTINGS OF EXPERIMENTS FROM NEW:UPDATES .......................... xiii

ORDERING INFORMATION FOR ADDITIONAL RESOURCES .................. xxix

PARTICIPANTS ...

°'°°'°°''°°°'*°°'°°'°° °°'°°°°°°°*'o°° ° ...... • • • ° ° • ° ° ° . . XXXlll

MATERIALS SCIENCE WITH PHOTONS AND NEUTRONS ....................... 1

Denis McWhan - Brookhaven National Laboratory

MAGNETO-RHEOLOGICAL FLUID TECHNOLOGY ........................... 29

John A. Marshall - University of Southern Maine

X-RAY EXCITED EMISSION OF Mn 2÷ IONS IN Mn: YAIO3 ....................... 35

M. A. Noginov, M. Warren, G. B. Loutts - Norfolk State University

AN INEXPENSIVE 2732°F MINIATURE ELECTRIC FURNACE FOR

TEACHING MATERIALS SCIENCE ......................................... 43

Luke Ferguson and Thomas Stoebe - University of Washington

TEACHING STATISTICAL QUALITY CONTROL AND PROCESS ANALYSIS

IN MATERIALS LABORATORY ............................................ 65

Neda S. Fabris -Califomia State University

SYSTEM UPGRADE OF ATOMIC OXYGEN GENERATOR FOR SPACE

MATERIALS RESEARCH *********************************** .... ° ° ° ° ° ° ° ° * ° 73

Kyo D. Song - Norfolk State University, Bruce Budde (LARSS) student - New Mexico State

University and Carolyn Hamilton (LARSS) student - University of New Mexico

INVESTIGATION OF THERMAL BLEACHING IN MANGANESE DOPED

ORTHOALUMINATE SINGLE CRYSTALS ................................... 95

George B. Loutts, Mikhail A. Noginov, Rosalind Wynne, Kai T. Ross and Talia Grandy -

Norfolk State University

THE MATERIALS SCIENCE OF SUPERCONDUCTING MAGNETS ............... 105

David Welch - Brookhaven National Laboratory

THE COLORFUL CHARACTER OF MATERIALS ............................. 137

Edward L. Widener- Purdue University

vii
LABORATORY MEASUREMENTOF J-INTEGRAL ..........................

Yulian Kin, Harvey Abramowitz, Toma Hentea, Jim Higley, and Jason Richards -

Purdue University - Calumet

143

USE OF A FOUR-POINT BEND APPARATUS TO DETERMINE THE MODULUS

OF ELASTICITY .......................................................

Richard B. Griffin, L. Roy Comwell, Carlos Yapura, Sivasubramaniam Krishnan

and John Hallford - Texas A&M University

153

MICROCHEMISTRY AND THE NEW SCANNING ELECTRON MICROSCOPES .... 165

Matthew J. Kasdan - Coto de Casa, and Stephen IC Kennedy - RJ Lee Group, Inc.

DETERMINATION OF THE CURIE TEMPERATURE IN FERRO AND

FERRIMAGNETS ......................................................

1L Valenzuela and E. Amano - National University of Mexico

173

EDUCATIONAL AND PUBLIC OUTREACH FOR THE MARS SAMPLE RETURN

PROJECT ............................................................. 183

S. Raj Chaudhury and Gae Golembiewski - Norfolk State University

GALVANOSTATIC POLARIZATION CURVES FOR TEACHING PURPOSES ....... 187

Carlos E. Umana - University of Costa Rica

THE UNDERLYING STRUCTURE OF ENGINEERING MATERIALS .............. 207

Mike L. Meier and Karl Ewald - University of California, Davis

RENDERING ASBESTOS INTO A NON-REGULATED MATERIAL ............... 217

Leon Petrakis - Brookhaven National Laboratory

EDUCATIONAL PROGRAMS AT BNL AND OTHER DOE LABS ................. 249

Karl Swyler - Brookhaven National Laboratory

LIQUID CRYSTAL p-AZOXYANISOLE IN MICROWAVE FIELD ................ 267

Jal N. Dahiya - Southeast Missouri State University

277 ARTIFICIAL MICROSTRUCTURES .......................................

Mike L. Meier - University of California, Davis

CRYSTAL GROWTH .................................................... 289

Merrill Rudes - Energy Concepts, Inc.

SIMULATING OPTICAL CORRELATION ON A PC ........................... 295

B. F. Dlaayer - Southeast Missouri State University

TRENDS FOR AUTOMOTIVE MATERIALS ................................. 311

John E. Fillion - DaimlerChrysler Corporation

DENDRITIC POLYMER PROPERTIES AND MACROMOLECULAR

ARCHITECTURE ....................................................... 337

Donald A. Tomalia - Michigan Molecular Institute in Midland

TUTORIALS FOR INTRODUCTION TO MATERIALS

ENGINEERING ........................................................ 351

Charles J. McMahon, Jr. - University of Pennsylvania

viii
ROOM TEMPERATURECREEPOF SOLDER................................ 365

Robert G. Stang - University of Washington

USE OF PIEZOELECTRIC CRYSTALS FOR VOICE RECOGNITION .............. 379

Harvey Abramowitz - Purdue University - Calumet

CONCURRENT ENGINEERING ........................................... 393

James B. Higley, Yulian B. Kin, Bernard W. Parsons 1/, and Christopher M. Prochnow -

Purdue University Calumet

STRETCHY "ELASTIC" BANDS II ......................................... 429

Alan If.. Karplus - Western New England College

PRODUCING PDF FILES USING ADOBE ACROBAT CAPTURE V2.01 ............ 445

Alfred E. McKenney - Williamsburg, Virginia

CAST IRON, WROUGHT IRON & STEEL (HISTORICAL PERSPECTIVE OF

PROPERTIES OF FERROUS MATERIAL) ................................... 455

Archie M. Cooke - Carson City, Nevada

ix

REVIEWERS FOR NEW:Update 98

Paul W. Brown

Professor Ceramics Science and Engineering

The Pennsylvania State University

Else Breval

Senior Research Associate

Materials Research Laboratory

The Pennsylvania State University

William Callister

Adjunct Professor of Metallurgy

University of Utah

James A. Clum

University of Detroit - Mercy

Technical notebooks and announcements of the workshop were provided by

NASA LANGLEY RESEARCH CENTER

xi

LISTING OF EXPERIMENTS FROM NEW:UPDATES

EXPERIMENTS & DEMONSTRATIONS IN STRUCTURES, TESTING, AND EVALUATION

NEW:Update 88

Sastri, Sankar. "Fluorescent Penetrant Inspection"

Sastri, Sankar. "Magnetic Particle Inspection"

Sastri, Sankar. "Radiographic Inspection"

NASA Conference Publication 3060

NEW:Update 89 NASA Conference Publication 3074

Chowdhury, Mostafiz R. and Chowdhury, Farida. "Experimental Determination of Material Damping

Using Vibration Analyzer"

Chung, Wenchiang R. "The Assessment of Metal Fiber Reinforced Polymeric Composites"

Stibolt, Kenneth A. "Tensile and Shear Strength of Adhesives"

NEW:Update 90 NIST Special Publication 822

Azzara, Drew C. "ASTM: The Development and Application of Standards"

Bates, Seth P. "Charpy V-Notch Impact Testing of Hot Rolled 1020 Steel to Explore Temperature Impact

Strength Relationships"

Chowdhury, Mostafiz R. "A Nondestructive Testing Method to Detect Defects in Structural Members"

Cornwell, L. IL, Griffin, IL B., and Massarweh, W.A. "Effect of Strain Rate on Tensile Properties of

Plastics"

Gray, Stephanie L., Kern, Kristen T., Harries, Wynford L., and Long, Sheila Ann T.

"Improved Technique for Measuring Coefficients of Thermal Extension for Polymer Films"

Halperin, Kopl. "Design Project for the Materials Course: To Pick the Best Material for a Cooking Pot"

Kundu, Nikhil. "Environmental Stress Cracking of Recycled Thermoplastics"

Panchula, Larry and Patterson, John W. "Demonstration of a Simple Screening Strategy for Multifactor

Experiments in Engineering"

Taylor, Jenifer A. T. "How Does Change in Temperature Affect Resistance?"

Wickman, Jerry L. and Corbin, Scott M. "Determining the Impact of Adjusting Temperature Profiles on

Photodegradability of LDPE/Starch Blown Film"

Widener, Edward L. "It's Hard to Test Hardness"

Widener, Edward L. "Unconventional Impact-Toughness Experiments"

NEW:Update 91 NASA Conference Publication 3151

Bunnell, L. Roy. "Tempered Glass and Thermal Shock of Ceramic Materials"

Lundeen, Calvin D. "Impact Testing of Welded Samples"

Gorman, Thomas M. "Designing, Engineering, and Testing Wood Structures"

Strehlow, Richard R. "ASTM - Terminology for Experiments and Testing"

Karplus, Alan K. "Determining Significant Material Properties, A Discovery Approach"

Spiegel, F. Xavier and Weigman, Bernard J. "An Automated System for Creep Testing"

Denton, Nancy L. and Hillsman, Vernon S. "Isotropic Thin-Walled Pressure Vessel Experiment"

Allen, David J. "Stress-Strain Characteristics of Rubber-Like Materials: Experiment and Analysis"

Dahl, Charles C. "Computer Integrated Lab Testing"

Cornwell, L. R. "Mechanical Properties of Brittle Material"

oo°

Xlll
NEW:Update 92 NASA Conference Publication 3201

Bunnell, L. Roy. "Temperature-Dependent Electrical Conductivity of Soda-Lime Glass and Construction

and Testing of Simple Airfoils to Demonstrate Structural Design, Materials Choice, and Composite

Concepts"

Marpet, Mark I. "Walkway Friction: Experiment and Analysis"

Martin, Donald H. "Application of Hardness Testing in Foundry Processing Operations: A University and

Industry Partnership"

Masi, James V. "Experiments in Corrosion for Younger Students By and For Older Students"

Needham, David. "Micropipet Manipulation of Lipid Membranes: Direct Measurement of the Material

Properties of a Cohesive Structure That is Only Two Molecules Thick"

Perkins, Steven W. "Direct Tension Experiments on Compacted Granular Materials"

Shih, Hui-Ru. "Development of an Experimental Method to Determine the Axial Rigidity of a

Strut-Node Joint"

Spiegel, F. Xavier. "An Automated Data Collection System For a Charpy Impact Tester"

Tipton, Steven M. "A Miniature Fatigue Test Machine"

Widener, Edward L. "Tool Grinding and Spark Testing"

NEW:Update 93 NASA Conference Publication 3259

Borst, Mark A. "Design and Construction of a Tensile Tester for the Testing of Simple Composites"

Clum, James A. "Developing Modules on Experimental Design and Process Characterization for

Manufacturing/Materials Processes Laboratories"

Diller, T. E. and A. L. Wicks, "Measurement of Surface Heat Flux and Temperature"

Denton, Nancy and Vernon S. Hillsman, "An Introduction to Strength of Materials for Middle School and

Beyond"

Fisher, Jonathan H. "Bridgman Solidification and Experiment to Assess Boundaries and Interface Shape"

Gray, Jennifer "Symmetry and Structure Through Optical Diffraction"

Kaxplus, Alan K. "Knotty Knots"

Kohne, Glenn S. "An Automated Digital Data Collection and Analysis System for the Charpy Impact

Tester"

Olesak, Patricia J. "Scleroscope Hardness Testing"

Speigel, F. Xavier, "Inexpensive Materials Science Demonstrations"

Wickman, J. L. "Plastic Part Design Analysis Using Polarized Filters and Birefringence"

Widener, Edward L. "Testing Rigidity by Torque Wrench"

xiv
NEW:Update94 NASAConferencePublication3304

Bruzan, Raymond and Baker, Douglas, "Density by Titration"

Dahiya, Jai N., "Precision Measurements of the Microwave Dielectric Constants of Polyvinyl Stearate and

Polyvinylidene Fluoride as a Function of Frequency and Temperature"

Daufenbach, JoDee and Griffin, Alair, "Impact of Flaws"

Fine, Leonard W., "Concrete Repair Applications and Polymerization of Butadiene by an "Alfin" Catalyst"

Hillsman, Vernon S., "Stress Concentration: Computer Finite Element Analysis vs. Photoelasticity"

Hutchinson, Ben, Giglio, Kim, Bowling, John, and Green, David, "Photocatalytic Destruction of an

Organic Dyd Using TiO2"

Jenkins, Thomas J., Comtois, John H., and Bright, Victor M., "Micromachining of Suspended Structures

in Silicon and Bulk Etching of Silicon for Micromachining"

Jacobs, James A. and Jenkins, Thomas J., "Mathematics for Engineering Materials Technology

Experiments and Problem Solving"

Karplus, Alan K., "Paper Clip Fatigue Bend Test"

Kohne, Glenn S., "Fluids With Magnetic Personalities"

Liu, Ping and Waskom, Tommy L., "Ultrasonic Welding of Recycled High Density Polyethylene (HDPE)"

Martin, Donald H., Schwan, Hermann, Diehm, Michael, "Testing Sand Quality in the Foundry (A Basic

University-Industry Partnership"

Shull, Robert D., '_Nanostructured Materials"

Wersfler, David E., "Introduction to Nondestructive Testing"

White, Charles V., "Glass Fracture Experiment for Failure Analysis"

Wickman, Jerry L. and Kundu, Nikhil K., "Failure Analysis of Injection Molded Plastic Engineered Parts"

Widener, Edward L., "Dimensionless Fun With Foam"

NEW:Update 95 NASA Conference Publication 3330

Brown, Scott, "Crystalline Hors d'oeuvres"

Karplus, Alan K., "Craft Stick Beams"

Kern, Kxisten, "ION Beam Analysis of Materials"

Kozma, Michael, "A Revisit to the Helicopter Factorial Design Experiment"

Pond, Robert B., St., "Recrystallization Art Sketching"

Roy, Rustum, "CVD Diamond Synthesis and Characterization: A Video Walk-Through"

Saha, Hrishikesh, "Virtual Reality Lab Assistant"

Spiegel, F. Xavier, "A Novel Approach to Hardness Testing"

Spiegel, F. Xavier, "There are Good Vibrations and Not So Good Vibrations"

Tognarelli, David, "Computerized Materials Testing"

Wickman, Jerry L., "Cost Effective Prototyping"

NEW:Update 96 NASA Conference Publication 3354

Chao, Julie, Currotto, Selene, Anderson, Cameron, Selvaduray, Guna, "The Effect of Surface Finish on

Tensile Strength"

Fabris, Neda S., "From Rugs to Demonstrations in Engineering Materials Class"

Ferguson, Luke, Stoebe, Thomas, "Hysteresis Loops and Barkhausen Effects in Magnetic Materials"

Karplus, Alan K., "Holy Holes or Holes Can Make Tensile Struts Stronger"

Koon, Daniel W., "Relaxation and Resistance Measurements"

Liu, Ping, Waskom, Tommy L., "Composite of Glass Fiber with Epoxy Matrix"

Song, Kyo D., Ries, Heidi R., Scotti, Stephen J., Choi, Sang H., "Transpiration Cooling Experiment"

South, Joe, Keilson, Suzarme, Keefer, Don, "In-Vivo Testing of Biomaterials"

Thorogood, Michael G., "Tensile Test Experiments With Plastics"

Widener, Edward L., "Brinelling the Malay Snail"

xv
NEW:Update97 NASAConferencePublication208726

Banerjee,Gautam,Miller,AlbertE."Understanding Galvanic Corrosion Tricks to Prevent Some Expensive

Failures"

Cadwell, John and Eric, Piippo, Steven. "Strength Testing of Composite Materials"

Diez, C. Ray. "Case Hardening: An Activity to Demonstrate Brinnell Hardness"

Draayer, B. F., Dahiya, J. N. "A Computerized Microwave Spectrometer for Dielectric Relaxation Studies"

Erickson, Glen C., Chung, W. Richard. "Effectiveness of Ultrasonic Testing Method in Detecting

Delamination Effects in Thick Composites"

Fabris, Neda S. "Learning More From Tensile Test Experiment"

Ferguson, Luke, Stoebe, Thomas. "Properties of Magnetic Ferrites With a Simple Fabrication Method"

Fine, Leonard W. "Demonstrating the Critical Properties of Carbon Dioxide"

Goranson, Ulf. "Jet Transport Structures Performance Monitoring"

Gorman, Thomas M. "Relationship Between Moisture Changes and Dimensional Change in Wood"

Griffin, R. B., Cornwell, L. 17,."Measurement of the Modulus of Elasticity Using a Three-Point Bend Test"

Homidany, Mtrook AI, Weick, Brian L. "A Device for Measuring the Elastic Modules of Spherical

Materials"

Hudson, John B., Svanes, Torkel, Bryson, Daniel, Sawyer, W. Gregory, "An Interactive Molecular

Dynamics Simulation of Atomic Behavior"

Karplus, Alan K. "Stretchy "Elastic" Bands"

Liu, Paul Cheng-Hsin, Moore, Kenneth, Ogu, Chris. "Rapid Prototyping Processes and Procedures"

Loutts, George B. "Crystal Growth of Mixed Optical Materials With the Automatic Czochralski Puller"

Lund, David W. "High Speed Civil Transport - Design Challenges"

Masi, James V. "Experiments in Diffusion: Gases, Liquids, and Solids For Under Five Dollars"

McCoy, Robert A. "How a Heat Pack Works"

Nydam, Andrew. "Low Dollar Tensile (Torsion) Tester"

Song, Kyo D. "Design of Hypervelocity Flow Generator and Its Flow Visualizations"

Spiegel, F. Xavier. "Medicine, Magic, Materials, and Mankind"

Umana, Carlos E. "The Combined Effect of Thermal Conductivity and Thermal Expansion in a PMMA

Plastic Heated by Thermal Radiation"

Vanasupa, Linda, Braun, David. "The Human Half-Adder: Understanding the Big Picture of Digital

Logic"

Warren, Matthew E., Loutts, George. "Optical Experiments With Manganese Doped Yttrium

Orthoaluminate, A Potential Material For Holographic Recording and Data Storage"

Werstler, David. "Case Studies in Metal Failure and Selection"

Whang. Kyumin and Hsu, Matthew. "Evaluating the Strength and Biodegradation of a Gelatine-Based

Material"

Williams, John R. "Corrosion Demonstration Utilizing Low Cost Materials"

NEW:Update 98 NASA Conference Publication

Griffin, Richard B., Comwell, L. Roy, Yapura, Carlos, Krishnan, Sivasubramaniam, Hallford, John. "Use

of a Four-Point Bend Apparatus to Determine the Modulus of Elasticity"

Karplus, Alan K. "Stretchy "Elastic" Bands II

McWhan, Denis. "Materials Science With Photons and Neutrons"

Meier, Mike L., Ewald, Karl. "The Underlying Structure of Engineering Materials"

Meier, Mike L., "Artificial Mierostructures"

Rudes, Merrill. "Crystal Growth"

Song, Kyo D., Budde, Bruce, Hamilton, Carolyn. "System Upgrade of Atomic Oxygen Generator for

Space Materials Research"

Stang, Robert G. "Room Temperature Creep of Solder"

Umana, Carlos E. "Galvanostatic Polarization Curves for Teaching Purposes"

xvi
EXPERIMENTS& DEMONSTRATIONSIN METALS

NEW:Update88 NASAConferencePublication3060

Nagy, James P. "Sensitization of Stainless Steel"

Neville, J. P. "Crystal Growing"

Pond, Robert B. "A Demonstration of Chill Block Melt Spinning of Metal"

Shull, Robert D. "Low Carbon Steel: Metallurgical Structure vs. Mechanical Properties"

NEW:Update 89 NASA Conference Publication 3074

Balsamel, Richard. "The Magnetization Process - Hysteresis"

Beardmore, Peter. "Future Automotive Materials - Evolution or Revolution"

Bunnell, L. Roy. "Hands-On Thermal Conductivity and Work-Hardening and Annealing in Metals"

Kazem, Sayyed M. "Thermal Conductivity of Metals"

Nagy, James P. "Austernpering"

NEW:Update 90 NIST Special Publication 822

Bates, Seth P. "Charpy V-Notch Impact Testing of Hot Rolled 1020 Steel to Explore Temperature Impact

Strength Relationships"

Chung, Wenchiang R. and Morse, Margery L. "Effect of Heat Treatment on a Metal Alloy"

Rastani, Mansur. "Post Heat Treatment in Liquid Phase Sintered Tungsten-Nickel-Iron Alloys"

Spiegel, F. Xavier. "Crystal Models for the Beginning Student"

Yang, Y. Y. and Stang, R_ G. "Measurement of Strain Rate Sensitivity in Metals"

NEW:Update 91

Cowan, Richard L.

Kazem, Sayyed M.

Krepski, Richard P.

Lundeen, Calvin D.

NASA Conference Publication 3151

"Be-Cu Precipitation Hardening Experiment"

"Elementary Metallography"

"Experiments with the Low Melting Indium-Bismuth Alloy System"

"Impact Testing of Welded Samples"

McCoy, Robert A. "Cu-Zn Binary Phase Diagram and Diffusion Couples"

Patterson, John W. "Demonstration of Magnetic Domain Boundary Movement Using

Assembled Videocam-Microscope System"

Widener, Edward L. "Heat-Treating of Materials"

an Easily

NEW:Update 92 NASA Conference Publication 3201

Dahiya, Jai N. "Phase Transition Studies in Barium and Strontium Titanates at Microwave

Frequencies"

Rastani, Mansur. "Improved Measurement of Thermal Effects on Microstructure"

Walsh, Daniel W. "Visualizing Weld Metal Solidification Using Organic Analogs"

NEW:Update 93 NASA Conference Publication 3259

Guichelaar, Philip J. "The Anisotrophy of Toughness in Hot-Rolled Mild Steel"

Martin, Donald H. "From Sand Casting TO Finished Product (A Basic University-Industry Partnership)"

Petit, Jocelyn I. "New Developments in Aluminum for Aircraft and Automobiles"

Smith, R. Carlisle "Crater Cracking in Aluminum Welds"

NEW:Update 94 NASA Conference Publication 3304

Gabrykewicz, Ted, "Water Drop Test for Silver Migration"

Kavikondala, Kishen and Gambrell, Jr., S. C., "Studying Macroscopic Yielding in Welded Aluminum

Joints Using Photostress"

K.repski, Richard P., "Exploring the Crystal Structure of Metals"

McClelland, H. Thomas, "Effect of Risers on Cast Aluminum Plates"

Weigman, Bernard J. and Courpas, Stamos, "Measuring Energy Loss Between Colliding Metal Objects"

xvii
NEW:Update95 NASAConferencePublication3330

Callister, William, "Unknown Determination of a Steel Specimen"

Elban, Wayne L., "Metallographic Preparation and Examination of Polymer-Matrix Composites"

Shih, Hui-Ru, "Some Experimental Results in the Rolling of Ni3A1 Alloy"

NEW:Update 96 NASA Conference Publication 3354

Callister, Jr., William D., "Identification of an Unknown Steel Specimen"

Elban, Wayne L., "Metallurgical Evaluation of Historic Wrought Iron to Provide Insights into MetalForming Operations and Resultant Microstructure"

Griff'm, R. B., Cornwell, L. R., Ridings, Holly E., "The Application of Computers to the Determination

of Corrosion Rates for Metals in Aqueous Solutions"

Hilden, J., Lewis, K., Meamaripous, Selvaduray, Guna, "Measurement of Springback Angle in Sheet

Bending"

Moss, T. S., Dye, R. C., "Experimental Investigation of Hydrogen Transport Through Metals"

Olesak, Patricia J., "2nd Steel Heat Treatment Lab: Austempering"

Spiegel, F. Xavier, "A Magnetic Dilemma: A Case Study"

Wersfler, David E., "Lost Foam Casting"

NEW:Update 97 NASA Conference Publication 208726

Dalton, William K., Olesak, Patricia J. "Making a Phase Diagram"

Hartwig. K. T., Haouaoui, M., Cornwell, L. R. "Alloy Composition Determinations"

Kin, Yulian, Abramowitz, Harvey, Hentea, Toma, Xu, Ying. "Life Estimate Based on Fatigue Crack

Propagation"

NEW:Update 98 NASA Conference Publication

Biancaniello, Frank S., Jiggetts, Rodney D., Ridder, Stephen D. "Characterization of High Nitrogen

Stainless Steel (HNSS) Produced via Inert Gas Atomization and Hip Consolidation"

Cooke, Archie M. "Cast Iron, Wrought Iron & Steel (Historical Perspective of Properties of Ferrous

Material"

Kin, Yulian, Abramowitz, Harvey, Hentea, Toma, Higley, Jim, Richards, Jason. "Laboratory Measurement

of J-Integral"

Q+,

XVUl
Experiments & Demonstrations in Polymers

NEW:Update 89 NASA Conference Publication 3074

Chung, Wenchiang 1L "The Assessment of Metal Fiber Reinforced Polymeric Composites"

Greet, Richard and Cobaugh, Robert. "Rubberlike Elasticity Experiment"

Kern, Kristen T., Harries, Wynford L., and Long, Sheila Ann T. "Dynamic Mechanical Analysis of

Polymeric Materials"

Kundu, Nikhil K. and Kundu, Malay. "Piezoelectric and Pyroelectric Effects of a Crystalline Polymer"

Kundu, Nikhil K. "The Effect of Thermal Damage on the Mechanical Properties of Polymer Regrinds"

Stibolt, Kenneth A. "Tensile and Shear Strength of Adhesives"

Widener, Edward L. "Industrial Plastics Waste: Identification and Segregation"

Widener, Edward L. "Recycling Waste-Paper"

NEW:Update 90 NIST Special Publication 822

Brostow, Witold and Kozak, Michael 1L "Instruction in Processing as a Part of a Course in Polymer

Science and Engineering"

Cornwell, L. R., Griffin, R. B., and Massarweh, W. A. "Effect of Strain Rate on Tensile Properties of

Plastics"

Gray, Stephanie L., Kern, Kristen T., Harries, Wynford L., and Long, Sheila Ann T. "Improved Technique

for Measuring Coefficients of Thermal Extension for Polymer Films"

Humble, Jeffrey S. "Biodegradable Plastics: An Informative Laboratory Approach"

Kundu, Nikhil. "Environmental Stress Cracking of Recycled Thermoplastics"

Wickman, Jerry L. and Corbin, Scott M. "Determining the Impact of Adjusting Temperature Profiles on

Photodegradability of LDPE/Starch Blown Film"

NEW:Update 91 NASA Conference Publication 3151

Allen, David J. "Stress-Strain Characteristics of Rubber-Like Materials: Experiment and Analysis"

Chowdhury, Mostafiz R. "An Experiment on the Use of Disposable Plastics as a Reinforcement in

Concrete Beams"

Gorman, Thomas M. "Designing, Engineering, and Testing Wood Structures"

Lloyd, Isabel K., Kolos, Kimberly R., Menegaux, Edmond C., Luo, Huy, McCuen, Richard H., and

Regan, Thomas M. "Structure, Processing and Properties of Potatoes"

McClelland, H. T. "Laboratory Experiments from the Toy Store"

Sorensen, Carl D. "Measuring the Surface Tension of Soap Bubbles"

Wickman, Jerry L. and Plocinski, David. "A Senior Manufacturing Laboratory for Determining Injection

Molding Process Capability"

NEW:Update 92 NASA Conference Publication 3201

Kundu, Nikhil K. "Performance of Thermal Adhesives in Forced Convection"

Liu, Ping. "Solving Product Safety Problem on Recycled High Density Polyethylene Container"

Wickman, Jerry L. "Thermoforming From a Systems Viewpoint"

NEW:Update 93 NASA Conference Publication 3259

Csernica, Jeffrey "Mechanical Properties of Crosslinked Polymer Coatings"

Edblom, Elizabeth "Testing Adhesive Strength" & "Adhesives The State of the Industry"

Elban, Wayne L. "Three-Point Bend Testing of Poly (Methyl Methacrylate) and Balsa Wood"

Labana, S. S. "Recycling of Automobiles an Overview"

Liu, Ping and Tommy L. Waskom, "Application of Materials Database (MAT.DB>) to Materials

Education and Laminated Thermoplastic Composite Material"

Marshall, John A. "Liquids That Take Only Milliseconds to Turn into Solids"

Quaal, Karen S. "incorporating Polymeric Materials Topics into the Undergraduate Chemistry Cor

Curriculum: NSF-Polyed Scholars Project: Microscale Synthesis and Characterization

of Polystyrene"

xix
NEW:Update 94 NASA Conference Publication 3304

Fine, Leonard W., "Concrete Repair Applications and Polymerization of Butadiene by an "Alfin" Catalyst"

Halperin, Kopl, Eccles, Charles, and Latimer, Brett, "Inexpensive Experiments in Creep and Relaxation

of Polymers"

Kern, Kristen and flies, Heidi R., "Dielectric Analysis of Polymer Processing

Kundu, Mukul and Kundu, Nikhil K., "Optimizing Wing Design by Using a Piezoelectric Polymer"

Kundu, Nikhil K. and Wickman, Jerry L., "An Affordable Materials Testing Device"

Stienstra, David, "In-Class Experiments: Piano Wire & Polymers"

NEW:Update 95 NASA Conference Publication 3330

Fine, Leonard W., "Polybutadiene (Jumping Rubber)"

Liu, Ping, and Waskom, Tommy L., "Plastic Recycling Experiments in Materials Education"

Liu, Ping, and Waskom, Tommy L., "Compression Molding of Composite of Recycled HDPE and

Recycled Tire Chips"

Masi, James V., "Experiments in Natural and Synthetic Dental Materials: A Mouthful of Experiments"

NEW:Update 96 NASA Conference Publication 3354

Brindos, Richard, Selvaduray, Guna, "Effect of Temperature on Wetting Angle"

Liu, Ping, Waskom, Tommy L., "Making Products Using Post Consumer Recycled High Density

Polyethylene: A Series of Recycling Experiments"

Spiegel, F. Xavier, "Elasticity, Plasticity and Anelasticity: Demonstrations"

NEW:Update 97 NASA Conference Publication 208726

Liu, Ping, Waskom, Tom L. "Study of Rheological Behavior of Polymers"

Sullivan, Laura L. "Correlation of Birefyingent Patterns to Retained Orientation in Injection Molded

Polystyrene Tensile Bars"

NEW:Update 98 NASA Conference Publication

Tomalia, Donald A. Dendritic Polymer Properties and Macromolecular Architecture"

xx
EXPERIMENTS& DEMONSTRATIONSIN CERAMICS

NEW:Update88

Nelson, James A.

Schull, Robert D.

NASA Conference Publication 3060

"Glasses and Ceramics: Making and Testing Superconductors"

"High Tc Superconductors: Are They Magnetic?"

NEW:Update 89 NASA Conference Publication 3074

Beardmore, Peter. "Future Automotive Materials - Evolution or Revolution"

Bunnell, L. Roy. "Hands-On Thermal Conductivity and Work-Hardening and Annealing in Metals"

Link, Bruce. "Ceramic Fibers"

Nagy, James P. "Austempering"

Ries, Heidi R. "Dielectric Determination of the Glass Transition Temperature"

NEW:Update 90 NIST Special Publication 822

Dahiya, J. N. "Dielectric Behavior of Superconductors at Microwave Frequencies"

Jordan, Gail W. "Adapting Archimedes' Method for Determining Densities and Porosities of Small

Ceramic Samples"

Snail, Keith A., Hanssen, Leonard M., Oakes, David B., and Butler, James E. "Diamond Synthesis with

a Commercial Oxygen-Acetylene Torch"

NEW:Update 91 NASA Conference Publication 3151

Bunnell, L. Roy. "Tempered Glass and Thermal Shock of Ceramic Materials"

Craig, Douglas F. "Structural Ceramics"

Dahiya, J. N. "Dielectric Behavior of Semiconductors at Microwave Frequencies"

Weiser, Martin W., Lauben, David N., and Madrid, Philip. "Ceramic Processing: Experimental

Design and Optimization"

NEW:Update 92 NASA Conference Publication 3201

Bunnell, L. Roy. "Temperature-Dependent Electrical Conductivity of Soda-Lime Glass"

Henshaw, John M. "Fracture of Glass"

Stephan, Patrick M. "High Thermal Conductivity of Diamond"

Vanasupa, Linda S. "A $.69 Look at Thermoplastic Softening"

NEW:Update 93 NASA Conference Publication 3259

Bunnell, L. Roy and Stephen Piippo, "Property Changes During Firing of a Typical Porcelain Ceramic"

Burchell, Timothy D. "Developments in Carbon Materials"

Dahiya, J.N., "Dielectric Measurements of Selected Ceramics at Microwave Frequencies"

Ketron, L.A. "Preparation of Simple Plaster Mold for Slip Casting and Slip Casting"

Masi, James V. "Experiments in Diamond Film Fabrication in Table Top Plasma Apparatus"

Werstler, David E. "Microwave Sintering of Machining Inserts"

NEW:Update 94 NASA Conference Publication 3304

Bunnell, L. Roy and Piippo, Steven, "The Development of Mechanical Strength in a Ceramic Material

During Firing"

Long, William G., "Introduction to Continuous Fiber Ceramic Composites"

Reifsnider, Kenneth L., "Designing with Continuous Fiber Ceramic Composites"

West, Harvey A. & Spiegel, F. Xavier, "Crystal Models for the Beginning Student: An Extension to

Diamond Cubic

NEW:Update 95 NASA Conference Publication 3330

Louden, Richard A., "Testing and Characterizing of Continuous Fiber Ceramic Composites"

xxi
NEW:Update96 NASAConferencePublication3354

Bunnell, L. Roy, Piippo, Steven W., "Evaluation of Chemically Tempered Soda-Lime-Silica Glass by

Bend Testing"

Dahiya, J. N., "Microwave Measurements of the Dielectric Relaxation in Different Grain Size Crystals of

BaTiO/'

Masi, James V., "Experiments in Sol-Gel: Hydroxyapatite and YBCO"

Stang, Robert G., "The Effect of Surface Treatment on the Strength of Glass"

Thomas, Shad, Hasenkamp, Erin, Selvaduray, Guna, "Determination of Oxygen Diffusion in Ionic Solids"

NEW:Update 98 NASA Conference Publication

Ferguson, Luke, Stoebe, Thomas. An Inexpensive 1600°C (2912°F) Miniature Electric Furnace for

Teaching Materials Science.

Welch, David. "Superconducting Magnets and Applications"

xxii
EXPERIMENTS& DEMONSTRATIONSIN COMPOSITES

NEW:Update88 NASAConference Publication 3060

Nelson, James A. "Composites: Fiberglass Hand Laminating Process"

NEW:Update 89 NASA Conference Publication 3074

Beardmore, Peter. "Future Automotive Materials - Evolution or Revolution"

Chung, Wenchiang 1L "The Assessment of Metal Fiber Reinforced Polymeric Composites"

Coleman, J. Mario. "Using Template/Hotwire Cutting to Demonstrate Moldless Composite Fabrication"

NEW:Update 90 NIST Special Publication 822

Bunnell, L. R. "Simple Stressed-Skin Composites Using Paper Reinforcement"

Schmenk, Myron J. "Fabrication and Evaluation of a Simple Composite Structural Beam"

West, Harvey A. and Sprecher, A. F. "Fiber Reinforced Composite Materials"

NEW:Update 91 NASA Conference Publication 3151

Greet, Richard J. "Composite Column of Common Materials"

NEW:Update 92 NASA Conference Publication 3201

Thornton, H. Richard. "Mechanical Properties of Composite Materials"

NEW: Update 93 NASA Conference Publication 3259

Masters, John "ASTM Methods for Composite Characterization and Evaluation"

Webber, M. D. and Harvey A. West. "Continuous Unidirectional Fiber Reinforced Composites:

Fabrication and Testing"

NEW:Update 95 NASA Conference Publication 3330

Craig, Douglas F., "Role of Processing in Total Materials"

Wilkerson, Amy Laurie, "Computerized Testing of Woven Composite Materials"

NEW:Update 97 NASA Conference Publication 208726

Gardea, Luis, Weick, Brian L. "A Method for Measuring the Shear Strength of Polymers and

Composites"

XXlll
EXPERIMENTS & DEMONSTRATIONS IN ELECTRONIC AND OPTICAL MATERIALS

NEW:Update 88

Sastri, Sankar. "Magnetic Particle Inspection"

NASA Conference Publication 3060

NEW:Update 89 NASA Conference Publication 3074

Kundu, Nikhil K. and Kundu, Malay. "Piezoelectric and Pyroelectric Effects of a Crystalline Polymer"

Molton, Peter M. and Clarke, Clayton. "Anode Materials for Electrochemical Waste Destruction"

Ries, Heidi R. "Dielectric Determination of the Glass Transition Temperature"

NEW:Update 90 NIST Special Publication 822

Dahiya, J.N. "Dielectric Behavior of Superconductors at Microwave Frequencies"

NEW:Update 91 NASA Conference Publication 3151

Dahiya, J.N. "Dielectric Behavior of Semiconductors at Microwave Frequencies"

Patterson, John W. "Demonstration of Magnetic Domain Boundary Movement Using an Easily Assembled

Videocam-Microscope System"

NEW:Update 92 NASA Conference Publication 3201

Bunnell, L. Roy. "Temperature-Dependent Electrical Conductivity of Soda-Lime Glass

Dahiya, Jai N. "Phase Transition Studies in Barium and Strontium Titanates at Microwave Frequencies"

NEW:Update 94 NASA Conference Publication 3304

Elban, Wayne L., "Stereographic Projection Analysis of Fracture Plane Traces in Polished Silicon Wafers

for Integrated Circuits"

Parmar, Devendra S. and Singh, J. J., "Measurement of the Electro-Optic Switching Response in

Ferroelectric Liquid Crystals"

NEW:Update 95 NASA Conference Publication 3330

Dahiya, Jai N., "Temperature Dependence of the Microwave Dielectric Behavior of Selected Materials"

Marshall, John, "Application Advancements Using Electrorheological Fluids"

Ono, Kanji, "Piezoelectric Sensing and Acoustic Emission"

Ries, Heidi R., "An Integrated Approach to Laser Crystal Development"

NEW:Update 96 NASA Conference Publication 3354

Jain, H., "Learning About Electric Dipoles From a Kitchen Microwave Oven"

NEW:Update 97 NASA Conference Publication 208726

Marshall, John A. "Magneto-Rheological Fluid Technology"

Umana, Carlos E. "How to Compute the Atomic Magnetic Dipole Moment of An Element: An

Engineering Approach"

NEW:Update 98 NASA Conference Publication

Abramowitz, Harvey. "Use of Piezoelectric Crystals for Voice Recognition"

Dahiya, J. N. "Liquid Crystal p-Azoxyanisole in Microwave Field"

Draayer, Bret. "Simulating Optical Correlation on a PC"

Kasdan, Matthew, Kennedy, Stephen K. "Microchemistry and the New Scanning Electron Microscopes"

Loutts, George B., Noginov, Mikhail A., Wynne, Rosalind, Ross, Kai T., Grandy, Talia. "Investigation

of thermal Bleaching in Manganese Doped Orghoaluminate Single Crystals"

Marshall, John A. "Magneto-Rheological Fluid Technology"

Noginov, M. A., Warren, M., Loutts, G. B. "X-ray Excited Emission of MN 2+ions in Mn: YAIO3

Valenquela, R., Amano, E. "Determination of the Curie Temperature in Ferro and Ferrimagnets"

xxiv
EXPERIMENTS& DEMONSTRATIONSIN MATERIALS SYSTEMS

NEW:Update96 NASAConferencePublication3354

Aceves, Salvador M., Smith, J. Ray, Johnson, Norman L., "Computer Modeling in the Design and

Evaluation of Electric and Hybrid Vehicles"

Benjamin, Robert F., "Experiments Showing Dynamics of Materials Interfaces"

Daugherty, Mark A., "Electrolytic Production of Hydrogen Utilizing Photovoltaic Cells"

Fine, Leonard W., "The Incandescent Light Bulb"

MacKenzie, James J., "Hydrogen -- The Energy Carrier of the Future"

NEW:Update 97 NASA Conference Publication 208726

Bunnell, L. Roy. "Weakening of Latex Rubber by Environmental Effects

Chadwick, Margaret. "Automotive Materials For the Next Millennium"

NEW:Update 98 NASA Conference Publication

Fabris, Neda S. "Teaching Statistical Quality Control and Process Analysis in Materials Laboratory"

Widener, Edward L. "The Colorful Character of Materials"

XXv
EXPERIMENTS & TOPICS IN MATERIALS CURRICULUM

NEW:Update 93 NASA Conference Publication 3259

Bright, Victor M. "Simulation of Materials Processing: Fantasy or Reality?"

Diwan, Ravinder M. "Manufacturing Processes Laboratory Projects in Mechanical Engineering

Curriculum"

Kundu, Nikhil K. "Graphing Techniques for Materials Laboratory Using Excel"

McClelland, H. T. "Process Capability Determination of New and Existing Equipment and

Introduction to Usable Statistical Methods"

Passek, Thomas "University Outreach Focused Discussion: What Do Educators Want From ASM

International"

NEW:Update 94 NASA Conference Publication 3304

Brimacombe, J. K., "Transferring Knowledge to the Shop Floor"

Butte, Harris M., "Emerging Materials Technology"

Constant, Kristen P. and Vedula, Kxishna, "Development of Course Modules for Materials Experiments"

Coyne, Jr., Paul J., Kohne, Glenn S., Elban, and Wayne L., "PC Laser Printer-Generated Cubic

Stereographic Projections with Accompanying Student Exercise"

Masi, James V., "Bubble Rafts, Crystal Structures, and Computer Animation"

McKenney, Alfred E., Evelyn D., and Berrettini, Robert, "CD-ROM Technology to Strengthen Materials

Education"

Olesak, Patricia J., "Understanding Phase Diagrams"

Scheer, Robert J., "Incorporating "Intelligent" Materials into Science Education"

Schwartz, Lyle H., "Technology Transfer of NIST Research"

Spiegel, F. Xavier, "Demonstrations in Materials Science From the Candy Shop"

Uhl, Robert, "ASM Educational Tools Now and Into the Future"

NEW:Update 95 NASA Conference Publication 3330

Belanger, Brian C., "NIST Advanced Technology Programs"

Berrettini, Robert, "The VTLA System of Course Delivery and Faculty in Materials Education"

Kohne, Glenn S., "An Autograding (Student) Problem Management System for the Compeuwtir Ilittur8"

Russ, John, "Self-Paced Interactive CD-ROMS"

NEW:Update 96 NASA Conference Publication 3354

Chaudhury, S. Raj, Escalada, Larry, Zollman, Dean, "Visual Quantum Mechanics - A Materials Approach"

Gulden, Terry D., Winter, Patricia, "Explorations in Materials Science"

McKelvy, Michael J., Birk, James P., Rarnakrishna, B. L., "Bringing Advanced Experimental Technology

Into Education"

McMahon, Jr., Charles J., "Labs on Videotape for Materials Science and Engineering"

Parkin, Don M., "Los Alamos - The Challenging World of Nuclear Materials Science"

Pendleton, Smart E., "Next Generation Multimedia Distributed Data Base Systems"

Russ, John C., "Impact of Multimedia and Network Services on an Introductory Level Course"

Spiegel, F. Xavier, "NEW:Update, The Experience of One College"

Wilkerson, Amy, Self, Donna, Rodriquez, Waldo J., Ries, Heidi R., "A "Problem Based Learning"

Approach to Reflection and Refraction"

Winter, Patricia S., "Business Involvement in Science Education"

xxvi
NEW:Update 97 NASA Conference Publication 208726

Chaudhury, S. Raj. "The National Educators' Workshop WEB"

Hudson, John B., Shadler, Linda S., Palmer, Mark A., Moore, James A. "Integration of Laboratory

Experiences Into An Interactive Chemistry/Materials Course"

Jacobs, James A., McKenney, Alfred E. "213 Experiments on CD-ROM From 10 Years of NEW:Updates"

Kayser, Jack R. "Structural Laboratory Manual"

Russ, John C. "Impact of Multimedia and Network Services on an Introductory Level Course"

Sawyer, W. Gregory, Bryson, Daniel, Svanes, Torkel, and Hudson, John B. "Effective Learning Through

Interactive Computer Simulation and Experimentation.

Shackelford, James F., Meier, Michael. "Computer Applications For The Materials Laboratory/Classroom:

Illustrating Structure and Diffraction"

Swyler, Karl J., Fine, Leonard W. "Preview of NEW:Update 98"

Winter, John M. Jr., Lipetzky, Kirsten G. "X-Ray Radiographic Exercises for an Undergraduate Materials

Lab"

NEW:Update 98

Berndt, C. C. "Internet Research and the Undergraduate Learning Experience"

Chaudhury, S. Raj, Golembiewski, Gae. "Educational and Public Outreach

Return Project"

Halada, Gary. "Earthquake Resistant Engineering Design"

Halada, Gary. "Teaching Through Engineering Disaster"

Higley, James B. "Concurrent Engineering"

McKenney, Alfred E. "Producing PDF Files Using Adobe Acrobat Capture V2.01"

McMabon, Charles J., Jr. "Tutorials for Introduction to Materials Engineering"

Petrakis, Leon. "Rendering Asbestos Harmless"

Swyler, Karl. "Educational Programs at BNL and Other DOE Labs"

NASA Conference Publication

for the Mars Sample

xxvii
A Multimedia Tool of Laboratory Experiments and Classroom Demonstrations

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XXVlil
ORDERING INFORMATION FOR ADDITIONAL RESOURCES

Twenty copies of the NATIONAL EDUCATORS' WORKSHOP PUBLICATIONS

(NASA-CPs from 1988 - 1997) are available on a fwst come, first served basis from

Dr. James A. Jacobs

Department of Technology

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

NASA publications may be ordered from

National Technical Information Center (NTIC)

Attention: Document Sales

5285 Port Royal Road

Springfield, VA 22161

or

National Center for Aerospace Information (CASI)

P. O. Box 8757

Baltimore, MD 21240-0757

BOB POND'S "FUN IN METALS" TAPE- AVAILABLE FROM

Johns Hopkins University

Maryland Hall 210

3400 N. Charles Street

Baltimore, MD 21218

Cost = $30.00

XXIX
JOURNAL OF MATERIALS EDUCATION SUBSCRIPTIONS:

JME has two categories of subscription: Institutional and Secondary. The institutional

subscription -- for university departments, libraries, government laboratories, industrial, or other

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$438.00 (US$). When the institution is already a subscriber, secondary subscriptions for

individuals and subdivisions are $45.00 (US$). (Secondary subscriptions may be advantageous

where it is the desire to preserve one copy for reference and cut up the second copy for ease of

duplication.) Two-year subscriptions for secondary for individual or subdivision are $75.00

(US$). Back issues of JME are $100 per year prior to 1996 (US$).

Other Materials Education Council Publications available •

Classic Crystals: A Book of Models - Hands-on Morphology. Twenty-Four Common Crystal

models to assemble and study. Aids in learning symmetry and Miller indices. $19.00.

A Set of Four Hardbotmd Volumes of Wood Modules - The Clark C. Heritage Memorial

Series. Published by MEC in cooperation with the U.S.Forest Products Laboratory, Madison,

Wisconsin. A compilation of nine modules entitled Wood: Its Structure and Properties (I3,

edited by Frederick F. Wangaard. A compilation of eight modules especially developed for

architects and civil engineers entitled Wood As A Structural Material (II). Also, Adhesive

Bonding of Wood and Other Structural Materials III and Wood: Engineering Design Concepts

Each of the first three wood volumes costs $31.00; the fourth volume costs $41.00. The

entire four-volume set is only $ 126.00 plus $4.50 shipping ($7.00 overseas).

The Crystallography Course - MEC's popular nine-unit course on crystallography. $39.00.

Instructional Modules in Cement Science - Five units prepared for civil engineering and

ceramic materials science students and professionals. $19.00.

Laboratory Experiments in Polymer Synthesis and Characterization - A collection of fifteen

peer-reviewed, student-tested, competency-based modules. $25.00. Topics include: bulk

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chromatography, x-ray diffraction and others.

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Please add $3.00 per book shipping charge.

Checks payable to The Pennsylvania State University

Managing Editor, JME

110 Materials Research Laboratory

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University Park, PA 16802

XXX
PARTICIPANTS

xxxi
xxxii

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©

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NATIONAL EDUCATORS' WORKSHOP 1998

PARTICIPANTS

Enrique Abola

Biology Department

Brookhaven National Laboratory

Harvey Abramowitz

Department of Engineering

Purdue University - Calumet

2200 169th Street

Hammond, IN 46323

219-989-2473

e-mail harveya@calumet.purdue.edu

Cheryl Alderman

North Carolina State University at UNCA

CPO 2360

One University Heights

Asheville, NC 28804-8511

828-251-6943

e-mail alderman@eos.ncsu.edu

Lori Aldridge

Northwestern High School

2503 W. Main Street

Rockhill, SC 29732

803-547-0969

e-mail LL 1516@aol.com

Peter Allen

Columbia University in the

City of New York

Tatiana Allen

Department of Physics, Geology

and Astronomy

University of Tennessee at Chattanooga

15 McCallie Avenue

Chattanooga, TN 37403

423-755-4520

e-mail Tatiana-Allen@ute.edu

Ginger L. F. Arrington

NASA Langley Research Center

MS 211

Hampton, VA 23681-0001

757-864-9696

e-mail g.1. freeman@larc.nasa.gov

Gerard Ateshian

Columbia University in the

City of New York

Empress A. Arthur

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-0953

e-mail earthur@vger.nsu.edu

Christopher C. Bemdt

SUNY at Stony Brook

Department of Materials Science

and Engineering

306 Old Engineering

Stony Brook, NY I 1794-2275

516-632-8507

e-mail cberndt@ccmail.sunysb.edu

Robert Berrettini

1019 Amelia Avenue

State College, PA 16802-4242

814-237-0301

rbb3@psu.edu

Kendra Brown

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-547-8329

XXXlll
Paul W. Brown

International Council for Materials Education

Pennsylvania State University

110 Materials Research Laboratory

University Park, PA 16802

814-865-5352

e-mail etx@psu.edu

C. Raj Chaudhury

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-2241

e-mail schaudhury@vger.nsu.edu

Michelle Churma

Prentice-Hall, Inc.

445 Hutchinson Avenue 4th floor

Columbus, OH 43235

e-mail michele_churma@prenhall.com

David Crew

Materials Science Division

Brookhaven National Laboratory

Carl Czajkowski

Department of Advanced Technology

Brookhaven National Laboratory

Jai N. Dahiya

Physics Department

Southeast Missouri State University

One University Plaza

MS 6600

Cape Girardeau, MO 63701

573-651-2390

e-mail dahiya@physics.semo.edu

C. Ray Diez

Industrial Technology

University of North Dakota

Box 7118

Grand Forks, ND 58202-7118

701-777-2198

Bret Draayer

Southeast Missouri State University

Physics Department

One University Plaza

Cape Girardeau, MO 63701

573-651-2391

e-mail draayer@physics.semo.edu

Chris Durning

Columbia University in the

City of New York

Sonja Ebron

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-8771

e-mail SEbron@vger.nsu.edu

Andy Eng

IT Associates

Columbia University

505 Havermeyer

Chemistry Dept.

300 Broadway

New York, NY 10027

212-854-8575

e-mail aeng@chem.columbia.edu

Neda S. Fabris

Mechanical Engineering

California State University, Los Angeles

5151 State University

Los Angeles, CA 90032

213-343-5218

e-mail nfabris@calstatela.edu

Huan Feng

Department of Applied Science

Brookhaven National Laboratory

xxxi¥
Luke Ferguson

University of Washington, MSE

1521 95th Street, NE

Seattle, WA 98115

206-525-4249

e-mail lukef@u.washington.edu

John E. Fillion

Manager of Body Materials Engineering

CIMS: 482-00-11

DaimlerChrysler Corporation

800 Chrysler Drive

Auburn Hills, MI 48326-2757

248-576-7472

e-mail jef2@chrysler.com

Leonard W. Fine

Department of Chemistry

Columbia University in the

City of New York

Havemeyer Hall

New York, NY 10027

212-854-2017

e-mail fine@chem.columbia.edu

Shanee' S. Frazier

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-626-3020

e-mail sfrazier@vger.nsu.edu

Morton Friedman

Columbia University

School of Engineering and Applied Science

500 West 120th Street

Room 510 Mudd

New York, NY 10027

212-854-2986

e-mail friedman@columbia.edu

Janis Fulgham

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-626-2994

James E. Gardner

Technical Staff Assistant

NASA Langley Research Center

Building 1219, Room 217

MS 118

Hampton, VA 23681-0001

757-864-6003

j. e.gardner@larc.nasa.gov

Dave Garza

Prentice-Hall, Inc.

One Lake Street

Upper Saddle River, NJ 07458

Edward S. Gillman

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-2632

gillman@jlab.org

Richard B. Griffin

Department of Mechanical Engineering

Texas A&M

College Station, TX 77843

409-845-9779

e-mail rgriffin@mengr.tamu.edu

Gary Halada

SUNY at Stony Brook

308 Old Engineering

Stony Brook, NY 11794-2275

e-mail ghalada@ccmail.sunysb.edu

_XV
James H. Haliburton

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-626-2631

Gar Harbottle

Chemistry Department

Brookhaven National Laboratory

Brian Keith Harris

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-626-2665

Charmagne D. Harris

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-855-9121

e-mail chharris@vger.nsu.edu

Corinta Harris

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-2381

John Heiser

Department of Advanced Technology

Brookhaven National Laboratory

Eric Helmet

Ocean Lakes High School

885 Schumann Drive

Virginia Beach, VA 2345

757-721-4110

Laura Henderson-Lewis

Materials Science Division

Brookhaven National Laboratory

Lael Herbert

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-626-2665

e-mail lherbert@vger.nsu.edu

Herbert Herman

Director

The Center for Thermal Spray Research

Brookhaven National Laboratory

Irving Herman

Columbia University in the

City of New York

James B. Higley

Purdue University Calumet

METS Department

Hammond, IN 46323

219-989-2584

e-mail higley@calumet.purdue.edu

Holli D. Horton

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-855-8432

e-mail hhorton@vger.nsu.edu

James A. Jacobs

Norfolk State University

Department of Technology

2401 Corprew Avenue

Norfolk, VA 23504

757-823-8109

e-mail j_.j acobs@vger.nsu.edu

Rodney D. Jiggetts

Physical Scientist

National Institute of Standards

and Technology

Bldg. 223, Room B 122

Gaithersburg, MD 20899

301-975-5122

xxxvi
Erik Johnson

NSLSDepartment

BrookhavenNational Laboratory

David Jones

Centerfor MaterialsResearch

Norfolk StateUniversity

2401CorprewAvenue

Norfolk, VA 23504

757-245-2063

e-mail djones@vger.nsu.edu

Paul Kalb

Department of Advanced Technology

Brookhaven National Laboratory

Alan K. Karplus

Department of Mechanical Engineering

Western New England College

Springfield, MA 01119-2684

413-782-1220

e-mail akarplus@wnec.edu

Matthew Kasdan

31932 Violeta Lane

Coto de Casa, CA 92679

949-858-1165

Stephen K. Kennedy

RJ Lee Group, Inc.350 Hochberg Road

Monroeville, PA 15146

724-325-1776

e-mail skennedy.rjlg.com

Thomas F. Kilduff

504 Brafferton Circle

Hampton, VA 23663

757-857-0272

e-mail tkilduff@whro.net

Yulian Kin

Purdue University Calumet

2200 169th Street

Hammond, IN 46323

219-989-2684

e-mail kin@nwi.calumet.purdue.edu

Diana P. LaClaire

Norfolk State University

Department of Technology

2401 Corprew Avenue

Norfolk, VA 23504

757-823-9072

e-mail d_laclaire@vger.nsu, edu

Jackie Li

The Cooper Union for the Advancement

of Science and Art

51 Astor Place

New York, NY 10003

201-353-4042

e-mail jli@cooper.edu

Philip Lippel

L-Cubed Consulting

61 Boston Street

Somerville, MA 02143

617-628-3704

George Loutts

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-2031

e-mail g_loutts@vger.nsu.edu

Socky Lugo

Columbia University in the

City of New York

212-854-2163

Nancy Manning

Biology Department

Brookhaven National Laboratory

John Marshall

University of Southern Maine

John Mitchell Center

Gorham, ME 04038

207-780-5447

e-mail jmarshal@usm.maine.edu

xxxvii
Alfred E. McKenney

516 Fairfax Way

Williamsburg,VA 23185-8200

757-221-0476

e-mail hdjc41@prodigy.corn

CharlesMcMahon

University of Pennsylvania

Department of MSE

3231 Walnut Street

Philadelphia, PA 19104

215-898-7979

e-mail cmcmahon@crsrn.upenn.edu

Denis McWhan

Associate Director for

Basic Energy Sciences

Brookhaven National Laboratory

P. O. Box 5000

Upton, NY 11973-5000

516-344-3927

e-mail mcwhanl @bni.gov

Mike Meier

University of California Davis

Department Chemical Engineering &

Materials Science

Davis, CA 95616

530-752-5166

e-mail mlmeier@ucdavis.edu

Ashanti Mitchell

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-527-5331

amitchell@vger.nsu.edu

Arnie Moodenbaugh

Brookhaven National Laboratory

Stephen Murray

Columbia University in the

City of New York

Shree Nayar

Columbia University in the

City of New York

Mikhail A. Noginov

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-2204

e-mail mnoginov@vger.nsu.edu

Catherine Osiecki

Brookhaven National Laboratory

516-344-7171

Leon Petrakis

Energy Efficiency and Conservation Division

Department of Applied Science

Brookhaven National Laboratory

P. O. Box 5000

Upton, NY 11973-5000

516-344-3037

e-mail petrakis@bnl.gov

Michelle Ramotowski

NSLS Department

Brookhaven National Laboratory

Anthony Renshaw

Columbia University in the

City of New York

Lester Richardson

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-588-2188

e-mail lrichardson@vger.nsu.edu

Thomas E. Roberts

Milwaukee Area Technical College

700 W. State Street

Milwaukee, WI 53210

414-297-7280

e-mail srobe@execpc.com

oo*

XXXVill
Bill Ross

Muskegon Community College

221 S. Quarterline Road

Muskegon, MI 49442

616-777-0367

e-mail rossb@muskegon.cc.mi.us

Merrill Rudes

Energy Concepts, Inc.

595 Bond Street

Lincolnshire, IL 60069

847-821-1900 ext. 312

e-mail eciengl @aol.com

James Schafer

Ivory Entrprises, Inc.

1625 Pine View Drive, NW

Issaquah, WA 98027

Carlos Smith

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-423-0053

e-mail vdamone@hotmail.com

Kyo D. Song

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-8105

e-mail kdsong@vger.nsu.edu

Peter Soo

Department of Advanced Technology

Brookhaven National Laboratory

Robert G. Stang

Department of Materials Science

and Engineering

University of Washington

Box 352120

Seattle, WA 98195-2120

206-543-2623

e-mail stang@u.washington, edu

James T. Stanley, II

Arizona State University

College of Engineering and Applied Sciences

Chemistry Biological & Materials

Engineering

P. O. Box 876006

Tempe, AZ 85287-6006

602-727-6309

e-mail jtsii@imap3.asu.edu

Toshi Sugama

Department of Applied Science

Brookhaven National Laboratory

Karl J. Swyler

Office of Educational Programs

Science Education Center

Brookhaven National Laboratory

Associated Universities, Inc.

P. O. Box 5000

Upton, NY 11973-5000

516-344-7171

e-mail swyler @bni.gov

Neda Tafreshi

P. O. Box 2059

Garden City, NY 11531

516-746-1590

e-mail gazanak@idt.net

Sturks Taylor, Jr.

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-623-3170

e-mail sttaylor@vger.nsu.edu

Jim Thomas

Columbia University in the

City of New York

xxxix
Donald A. Tomalia

Michigan Molecular Institute in Midland

1910 West Saint Andrews Road

Midland, MI 48640

517-832-5555 ext. 601

e-mail tomalia@mmi.org

Carlos E. Umana

School of Mecanical Engineering

University of Costa Rica

San Pedro, Costa Rica

506-207-4548

e-mail cumana@pacuare.eie.ucr.ac.cr

Raul Valenzuela

Institute for Materials Research

National University of Mexico

P. O. Box 70-360

Mexico 04510 Mexico

525-622-46 53

e-mail monj aras@servidor.unam.mx

David Welch

Head - Materials Science Division

Department of Applied Science

Brookhaven National Laboratory

P. O. Box 5000

Upton, NY 11973-5000

516-344-3517

e-mail welch@sun2.bnl.gov

Charles V. White

Kettering University

1700 W. Third Avenue

Flint, MI 48504-4898

Edward L. Widener

Purdue University

Knoy Hall 119

West Lafayette, IN 47907-1317

765-494-7521

e-mail elwidener@tech.purdue.edu

Amy Wilkerson

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-2096

e-mail awilkerson@vger.nsu.edu

Eyad Youssef

Nofolk State University

2401 Corprew Avenue

Norfolk, VA 23504

757-823-8831

eyad@vger.nsu.edu

Bo Yu

Instrumentation Division

Brookhaven National Laboratory

Vladimir Zajic

Brookhaven National Laboratory

Mike Zarcone

Brookhaven National Laboratory

xl
PARTICIPANTS

xli

NATIONAL EDUCATORS' WORKSHOP

Update 98: Standard Experiments

in Engineering Materials, Science,

and Technology

November 1 - 4, 1998 - Brookhaven National Laboratory

Columbia University and Gateway Coalition

Stony Brook State University of New York

l J

Sponsored by

Brookhaven National Laboratory

Columbia University and Gateway Coalition

School of Engineexi_ and Applied Science

with the support of

National Aeronautics & Space

Administration

Langley Research Center

ST@NY

BR@OK

Amexican Society for F.ngineezing Education

American Society for Testing and Materhds

ASM Intematiomd

Boein 8 Commen:ial Airplane Company

Los Alamos National Laboratory

Council for Mate._als Education

Oak Ridge National Laboratory

Norfolk State University

School of SCience and

Technology

National Imtitut_ of Standanls & Technology

Mamiab Science & Engineem_ Labona_es

xliii
WELCOME

.... |i_'

il

Karl Swyler

Jim Jacobs

xliv
CONTRIBUTIONS

Jim Gardner

Diana LaClaire

xlv
CONTRIBUTIONS (Continued)

Donald Tomalia and Len Fine

Chris Berndt

xivi
REGISTRATION

D

Diana La Claire, Ginger Arrington, and Karl Swyler

Ginger Arrington

xlvii

MINI WORKSHOPS

AT

BROOKHAVEN NATIONAL LABORATORY

AND

SUNY AT STONY BROOK

xlix

BNL MINI-WORKSHOPS

TUESDAY, NOVEMBER 3, 1998

1. Accelerators in Materials Processing - Mr. Chuck Carlson, Physics Department - Application

of BNL'S Van De Graaff to testing electronic materials and fabricating microstructures.

2. Advanced Magnet Development - Dr. Laura Henderson-Lewis, Materials Science Division -

Studies in development of superconducting accelerator magnets and "nard' magnets for energy-efficient

motors.

3. Coating Technology - Dr. Toshi Sugama, Department of Applied Science - Explore and evaluate

the use of low-cost organic coatings to provide corrosion resistance.

4. Electronic Detector Technology - Dr. Velko Radeka, et. al., Instrumentation Division -

Investigate development of state-of-the-art systems for detecting high-energy particles and photons.

5. Failure Analysis - Dr. Carl Czajkowski, Department of Advanced Technology - Apply techniques

and methods of identifying metallurgical failure modes in nuclear reactor applications.

6. Hard X-ray Micromachining - Dr. Erik Johnson, NSLS Department - Use of synchrotron

radiation in the production of microstructures and characterizing the product.

7. High Tc Superconductors - Dr. Amie Moodenbaugh - Explore the properties of Hi Tc materials

and possibilities for their practical application.

8. Materials Science at Large Facilities - Dr. John Larese, et. al. Chemistry Department - Review

principles of techniques used to characterize materials with synchrotron radiation and neutrons.

9. Nuclear Chemistry: Art and Archeology - Dr. Gar Harbottle, chemistry Deparmaent - Investigate

basic concepts of nuclear chemistry and review their application to studies in art and archaeology.

10: Oxidation and Degradation of Organic Martials - Dr. Peter Soo, Department of Advanced

Technology - Review/explore techniques used to study and assess the impact of oxidation on cable

insulation.

11. Protein Crystallography Dr. Enrique Abola, Biology Department - Investigate the

fundamentals of structural analysis by diffraction and educational applications of BNL's protein data

bank.

12. Trace Element Analysis - Dr. Keith Jones, Department of Applied Science - Detection of trace

elements by X-ray fluorescence, and applications to materials science and engineering.

13. Wasteform, Container and Barrier Materials - Dr. Paul Kalb, Department of Advanced

Technology - Review/explore properties of materials relevant to hazardous waste management.

14. X-Ray Microtomography - Dr. Betsy Dowd, National Synchrotron Light Source - Use of X-rays

and advanced computational techniques to permit 3-d visualization of internal microstructure.

li
SUNY AT STONY BROOK WORKSHOPS

TUESDAY, NOVEMBER 3, 1998

1. Workshop on Material Properties of Biomedical Materials

2. Tour and Demonstration of Facilities: Coatings and Manufacturing Technology

3. Workshop on the Fracture Probability and Statistics of Glass

Christopher C. Berndt

Department of Materials Science and Engineering

SUNY at Stony Brook

lii
MINI WORKSHOPS

liii
MINI WORKSHOPS (Continued)

n

liv
MINI WORKSHOPS (Concluded)

i il iiii! ̧

IV

MATERIALS SCIENCE WITH

PHOTONS AND NEUTRONS

Denis McWhan

Associate Director

for Basic Energy Sciences

Brookhaven National Laboratory

P. O. Box 5000

Upton, New York 11973-5000

516-344-3927

e-mail mcwhanl @bni.gov

1
Denis McWhan •

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Understanding Molecular Biology

Neutron beams from the HFBR are used by biologists to discover the molecular structure of proteins,

nucleic acids, and other cellular components. Determining these structures is a critical step in

understanding the functioning of muscle, ribosomes, chromatin, enzymes and many other

biomolecules. Medical applications may result directly from this research, but more often indirectly,

by providing a roadmap for the design of specific drugs. Recent research at the HFBR provides

insights into:

- Activation of plasminogen in blood clotting

- Packaging of DNA in chromatin

- Structure of the immunosuppressant cyclosporin

- Location of anesthetics and anti-viral drugs in the cell membrane

Dissolving Blood Clots

Neutrons are uniquelysuited to probe the shapeand changes

in shape of biomolecules.Studies at the HFBR have shownthat

the inactive form of plasminogen circulatingin the bloodstream

is a compactmolecule. When activated ina bloodclot,it

unfoldsto expose a potent enzyme that dissolvesthe network

of filaments that entangle blood cells. The action of a new drug,

Tissue PlasminogenActivator(TPA), can be understoodwith

this unfoldingmechanism, and ways to increase its

effectivenessin treatingvictims of heart attacksand strokesare

beingpursued.

DNA Packaging

X-ray experiments by J. Watson and F. Crick established the famous double-helix structure of DNA

(top left), which holds the blueprint of life. Recent neutron studies at the HFBR revealed the structure of

a higher order of its packaging (center right) - consisting of about 2 meters of DNA (blue) and protein

cores (red) - which subsequently fold into chromosomes (bottom left). These studies are crucial to the

understanding of cellular function, the expression of selected proteins, DNA repair and reproduction.

Membrane Bound Drugs

Lipid membranes enclose all cells, providing containment, anchoring

protein channels, and aiding in defense mechanisms. These intrinsic

membrane functional groups are uniquely recognizable using neutron

diffraction. A small anti-viral drug, amantadine, was recently located

deeply buried in the fatty layer of the membrane• This surpnsing

result suggests that the drug prevents infection by the common cold

virus (shown) by blocking its penetration of the membrane. Similarly

constructed drugs may prove effective against other virus attacks.
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28
MAGNETO-RHEOLOGICAL FLUID TECHNOLOGY

John Marshall

University of Southern Maine

John Mitchell Center

Gorham, Maine 04038

Telephone 207-780-5447

e-mail j marshal@usm.maine.edu

29
John Marshall

30
Magneto-Rheological Fluid Technology

John A. Marshall, PHD

University of Southern Maine

Key Words:

Hydraulics, mechanical power transmission, and rheology.

Perquisite Knowledge:

Elementary concepts of power transmission.

Objective:

To observe the tunable characteristics of magneto-rheological fluids.

To understand the potential power transmission advantages of these

fluids.

Equipment and Supplies:

Magneto-rheological clutch assembly and power supply.

Introduction:

Magneto-rheological fluids change their flow characteristics when

subjected to an electrical field. Response, which takes only milliseconds,

is in the form of a progressive gelling that is proportional to field strength.

With no field present, the fluid flows as freely as hydraulic oil (Korane,

1991).

Magneto-rheological fluids represent a technology that has the potential to

widen the performance range of automated electromechanical and

electrohydraulic equipment. Research and ongoing developments are

refining this technology and experts predict an important future for these

fluids.

31
Importance of Magneto-rheological Fluids:

Current automation capabilities are not advanced enough to build a robot

that could play tennis. Even though cameras and computers could direct

the robot towards a ball, robot's move in an awkward, lumbering fashion

because conventional hydraulic valves cannot keep pace with the

commands of the computerized controllers.

With magneto-rheological fluid technology, this type of response time is

possible. This technology will allow devices that can operate instantly and

without mechanical valves. Increased productivity and better product

quality through more dependable and responsive automated equipment is

just a small part of what this maturing technology can deliver.

How Magneto-rheological Fluid Functions:

Magneto-rheological fluids are composed of two primary components.

They are the carrier fluid and the suspended particles. The carrier fluid

needs to be a good insulator, compatible with the materials they contact.

Typical particle materials include polymers, minerals, and ceramics (Scott,

1984).

When an magnetic field is applied to the fluid, positive and negative

charges on the particles respond by separating, so each particle then has

a positive end and a negative end. Particles of the magneto-rheological

fluid then link together in the same manner that the north pole of one

magnet is attracted to the south pole of another magnet (Duclos, 1988).

Potential Applications:

Magneto-rheological fluids can change from solids to liquids so fast, they

will work well with fast-acting computers. These characteristics suggest a

number of unusual engineering applications such as fluid clutches and

vibration isolators (Duclos, 1988).

According to Hans Conrad, professor of materials science and

engineering at North Carolina State University, magneto-rheological fluids

will lead to a whole new generation of brakes, automatic transmissions,

actuator devices, hydraulic valves, pump parts, and motors (Conrad,

1992).

32
Procedu re:

Safety Considerations:

1. Protective eye wear is mandatory for all those in the lab area.

2. Read the operating instructions that accompany the magnetorheological clutch assembly and power supply.

. Obtain a "Material Data Safety Sheet" on the fluid from the

supplier. Read the sheet completely and ask questions to any

information you do not understand.

Observing the tunable clutch assembly:

1. With the power supply off, notice how easily the shafts can be

rotated by hand.

2. Increase the power output through the range of 4, 8, 16, 32, 60,

and 80 % and record your findings on the data sheet.

. Vary the cycling frequency through the range of 4, 8, 16, and 32 Hz

and notice the pulsating sensation while rotating the shafts.

Record your findings on the data sheet.

Sample Data Sheet:

Record below the characteristics of the clutch when varying the power

output.

Record below the characteristics of the clutch when varying the cycling

frequency.

Instructor Notes:

1. The power being transmitted through the clutch increases

proportionally when the power output is increased.

2. The impulses of power transmission increase as the cycling

frequency is increased.

33
References:

Korane, K.: Putting ER Fluids To Work. Machine Design, May 9,1991,

pp. 52-57.

Scott, D.: Amazing Hardening Fluids Open a New World of Hydraulic

Drives. Popular Science, April 1984, pp. 42-46.

Duclos, T.G.: Electrorheological Fluids and Devices. Automotive

Engineering, December 1988, pp.45-48.

Conrad, H.: The Impact of ER Fluids. Compressed Air Magazine,

March 1992, pp.14-17.

"Procedure Demonstration Power Supply Controller" directions which

accompany the tunable clutch.

Source of Supplies:

Internet resource to supplies and additional information:

http://www.rmit.edu.au/departments/ch/rmpc/

Biographical Information:

Dr. JOHN ALLEN MARSHALL taught senior high school prior to receiving

his Ph.D. from Texas A&M University. He has seventeen years of

university teaching experience, and is currently the Director of the Power

and Energy curriculum and laboratories as well as the Internship

Coordinator for the University of Southern Maine's Department of

Technology.

34
X-RAY EXCITED EMISSION OF

Mn 2+ IONS IN Mn:YAIO3

M. A. Noginov

M. Warren

and

G. B. Loutts

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, Virginia 23504

Telephone: 757-683-2204

e-mail mnoginov@vger.nsu.edu

35
M. A. Noginov

36
X-ray excited emission of Mn 2÷ ions in Mn:YAIO3

M. A. Noginov, M. Warren, G. B. Loutts

Center for Materials Research,

Norfolk State University, Norfolk, VA

Keywords:

Luminescence, Transition-metal ions in solids, Scintillators, Optical measurements

Prerequisite knowledge:

The student

1. should have basic understanding of different types of electromagnetic radiation (X

rays, visible light)

2. should have basic knowledge of the materials science and/or solid-state physics and/or

optical spectroscopy

Objectives:

The objectives of this experiment are:

• to demonstrate to the student the possibility of the X ray-to-visible energy

conversion in solid states,

to teach the student the basics of operation of X ray sources and conducting optical

spectroscopic measurements,

to demonstrate to the student the example of the analysis of the material parameters

on the basis of the results of the spectroscopic measurements.

Equipment and supplies:

• The X-ray diffractometer Rigaku D/Max-2200 TB, Cu K,_l radiation, 3.=0.154 nm.

[Any standard source of X ray radiation can be used instead].

• The Mn:YA103 crystal. [The experiment can also be conducted using many different

scintillator crystals. The interpretation of the observed visible emission in each

particular case will depend on the nature of the luminescent ion.]

• Model SR541 optical light chopper and model SR540 chopper controller from

Stanford Research Systems, Inc. [Any similar chopper and controller can be used].

• l m long and 8 mm in diameter optical bundle. We used the bundle from the light

source model 1-150 from CUDA products corp. [Other similar bundles can be used as

well.]

• Model H20 monochromator from ISA John Yvon, SPEX.. (Any similar

monochromator can be used.]

• Any photomultiplier tube (PMT) with the maximum sensitivity in the visible range of

the spectrum.

• Tektronix TDC 774 color four channel digitizing oscilloscope. [Any digitizing

oscilloscope with the storage function can be used].

37
The high voltage power supply for PMT (0-1500V). We used FLUKE high voltage

power supply model 405B from FLUKE Mfg. Co. Inc. [Any power supply with

similar characteristic can be used.]

• Electrical cables.

Background introduction:

In Ref. [1], Mn doped YA103 was shown to be a promising material for holographic

recording and optical data storage. The detailed characterization of Mn:YA103 requires

the spectroscopic study of all Mn valence states in the crystal. However, the ground state

level in Mn 2÷ (6A1) is the only sextet level in the system and all ground state transitions in

Mn 2÷ are spin-forbidden and weak [2]. This makes optical excitation of Mn 2÷

luminescence very difficult, especially in the presence in the crystal of other Mn valence

states.

In scintillator crystals the conversion of X-ray excitation into visible emission occurs in

three common stages: conversion, transfer, and luminescence [3, 4]. In the first stage the

radiation produces primary very hot electrons which in turn produce a cloud of secondary

hot electrons thermalizing to electron hole pairs of low energy. In the second stage

electron hole pairs very likely form excitonic centers of many forms in the scintillation

centers. At this stage we have the process of energy transfer from these centers to the

scintillation centers. In the third stage the scintillation centers (Mn 2÷ in our case) radiate

the energy (visible light).

Experiment:

We found that Mn doped YA103 crystals, single doped and co-doped with Ce, emit

greenish light when excited with X-rays in the X-ray diffractometer (Pdgaku D/Max-2200

TB, Cu K_l radiation, _,=0.154 urn). We collected luminescence in the chamber of the

diffractometer using the optical fiber bundle, sent light to the input slit of a small

monochromator that we attached to the X-ray set Up, and detected the signal with a

photomultiplier tube. The schematic of the experiment.is shown in Figure 1.

To increase the signal-to-noise ratio, we chopped the X-ray beam in the chamber with a

regular chopper used in optical spectroscopy. The obtained emission spectrum (collected

point by point using the averaging oscilloscole) is shown in Figure 2. It consists of the

relatively broad emission line peaking at 0.53 ktm and more narrow band centered at =0.71

lam.

We attribute the 0.71 ktm emission band to Mn 4÷ ions (see Refs. [1,5,6]) and the 0.53 pan

emission to Mn 2÷ ions. (In Ref. [7] the luminescence of Mn 2÷ ions in YA103 was reported

to be centered at 560 nm. However, many spectroscopic properties of Mn ions (in

different valence states) reported in Ref. [7] were different from those in our crystals. As

it was discussed in Ref. [3], possible reasons for this discrepancy are the different crystal

growth technique (optical floating zone) and the post-growth annealing of the crystals

used in work [7].) Using the analogy with the literature, we assign the 0.53 _tm

luminescence to the transition 4T1---_6AI in Mn 2÷.

38
Ocsflloseope

0 0

Controller for cho _er

I V---_ O0

X ray source

Chopper

_t" -Synchronization

PMT

Optical

)undle

Chamber of the X ray

d ifffact omet er

M n:YAIO3 crystal

on the mount

Power supply

for PM T

Figure 1. Experimental set up.

r--

0)

h..

tO

o9

•_

E

I.H

1.1

0.9

0.7

0.5

0.3

0.1

-0.1

0

o

0

o

o

0 •

oO

o • o o

o o • o

o

,0

0

i •

360 410 460 510 560 610 660 710 760

Wavelength, nm

Figure 2. Visible emission excited in Mn(0.5%):YA103 with X-ray beam (_.=0.154 nm).

The horizontal bar in the figure shows the spectral resolution.

39
The Tanabe-Sugano diagram (showing the energies of different electronic states in

transition metal ions as a function of the crystal field Dq) for a 3d 5 electron configuration,

calculated in Ref. [8] for the ratio of the Racah parameters C/B=5.55, is shown in Figure

.

6O

4O

30

20

10

EIB

0 10' 2'0 '::50

Dq/B

Figure 3. The Tanabe-Sugano energy level diagram of a 3d 5 system (calculated in Ref. [8]

for C/B=5.55).

As it follows from Figure 8, the energy gap between the levels 6A1 and 4TI is strongly

dependent on the crystal field Dq, being larger at small Dq and smaller at large Dq. Since

the crystal field splitting is larger in octahedml sites than in dodecahedral or tertahedral

sites (Dqo:Dqd:Dqt=l :-1/2:-4/9, where the negative signs indicate that dz _ and dxz.y z become

the more stable set relative to the other three d orbitals [2]), the type of the site

occupancy of Mn 2÷ ion can be determined, in a first approximation, by the color of Mn 2÷

luminescence. As follows from Table 1 summarizing data on Mn 2÷ emission in various

crystals, green color of Mn 2+ luminescence observed in our experiment is the evidence

that Mn 2+ ions occupy in YA103 dodecahedral (y3+) but not octahedral (A13+) sites. This

consideration confirms our initial assumption based on the ion sizes and the decrease in

the lattice parameters.

40
Crystal

YAIOj

ZnAI204

LaAIO3

MgAI204

Y3Sc2Ga3012

YsAIs0_2

Y3Als01z

Site coordination

Dodecahedral

Tetrahedral

Dodecahedral

Tetrahedral

(low Mn

concentration)

Dodecahedral

Dodecahedral

Dodecahedral

Strongly distorted

octaheder

Wavelength of the

maximum

luminescence, nm

Color of

530

luminescence

509

518 green

530 green

573

585

green

green

yellow

yellow-orange

orange

orange

red

red

Temperature,

K

300

4.2

4.2

300 (.9)

12

12

300

A1203 Octahedml

Ca3Ga2Ge4Ot4 Octahedral

Mg2SiO4

Reference

Th_ work

[9]

[9]

[21]

[I1]

[11]

[8]

[9]

609

600

625

650

4.2

300

i

Table 1. Site symmetry and luminescence wavelength of Mn 2+ ions in different hosts

[1o]

[22]

Acknowledgments:

The work was partially supported by the AFOSR/BMDO grant #F49620-98-1-0101 and

DOE grant #DE-FG01-94EW11493. The authors thank C. E. Bonner, N. Noginova, and

C. Jackson for the help with experiments.

References:

1. G. B. Louts, M. Warren, L. Taylor, R. R. Rakhimov, H. R. Ries, G. Miller III, M. A.

Noginov, M. Curley, N. Noginova, N. Kukhtarev, J. C. Caulfield, P. Venkateswarlu,

"Manganese-doped yttrium orthoaluminate: A potential material for holographic

recording and data storage", Phys. Rev. B, 57, pp. 3706-3709 (1998).

2. R. G. Bums, "Mineralogical applications of crystal field theory", Second Edition,

Cambridge University Press, Cambridge, 1993, 551 pp.

3. A. Lempicki, A. J. Wojtowicz, E. Berman, "Fundamental limits of scintillator

performance", Nuclear Instruments and Methods in Physics Research A, 333, pp.

304-311 (1993).

4. J. Anderson, P. Dorenbos, C. W. E. van Eijk, "Calculation of energy levels of cerium in

inorganic scintillator crystals", Materials Research Society Symposium Proceedings,

Vol. 348, pp., 355-365 (1994).

41
3. M. A. Noginov, N. Noginova, M. Curley, N. Kukhtarev, H. J. Caulfield, P.

Venkateswarlu,G. B. Loutts "Optical characterizationof Mn:YA103, material for

holographicrecordinganddatastorage",JOSAB, 15, pp. 1463-1468 (1998).

6. M. A. Noginov, G. B. Loutts, "Spectroscopic studies of Mn 4+ ions in yttrium

orthoaluminate", submitted to JOSA B.

7. V. A. Antonov, P. A. Arsenev, Sh. A. Vakhidov, E. M. Ibragimova, "Colour centers in

yttrium aluminate crystals activated with transition metal ions", phys. star. sol. (a),

22, pp. 391-399 (1974).

8. B. Henderson, G. F. Imbusch, "Optical spectroscopy of inorganic solids", Clarendon

Press, Oxford, 1989, 645 p.

42
AN INEXPENSIVE 2732°F

MINIATURE ELECTRIC FURNACE FOR

TEACHING MATERIALS SCIENCE

Luke Ferguson

and

Thomas Stoebe

Department of Materials Science and Engineering

University of Washington

Box 352120

Seattle, Washington 98195-2120

Telephone 206-543-7090

e-mail lukef@u.washington.edu

stoebe@u.washington.edu

43
Luke Ferguson

44
An Inexpensive 2732°F Miniature Electric Furnace for

Teaching Materials Science

Luke Ferguson and Thomas Stoebe

The Department of Materials Science and Engineering

University o.[ Washington, Box 352120

Seattle, WA 98195-2120

Key Words

High temperature electric tiu'nace, high temperature refi-actory materials, fiu'nace design,

thermal conductivity, heat transIer, silicon carbide heating element, materials compatibility,

ceramic materials, insulation and energy efficiency, energy balance, alumina and zircoma fibrous

refi'actory board, alumina cement, moldable refi'actorv materials, thermal stress and thermal shock

resistance, thermal expansion, platinum thermocouples, thermometry.

Prerequisite Knowledge

Basic laboratory salety skills are required, and supervision by qualified personnel is also

required. College level chemistry, physics or materials science, basic electronics, and basic

construction skills such as using cements or mortars and insulaling materials are recommended

tbr those involved in this work. Experience in the operation of a standard pottery kiln or furnace

would definitely be helptui. Some basic knowledge about refi-actory ceramics and metals and

their compatibility issues is strongly recommended.

Abstract

This experiment teaches pnnciples of high-temperature electric tin-nace design, energy

efficiency, and thermal properties of materials. The timaace described in this experiment is

constructed with commercially available retiactory materials, and is built on a small scale to

minimize construction cost. The tia-nace is capable of reaching temperatures tar above those of a

standard pottery kiln, and may be used fbr many interesting experiments involvmg technical

ceramics and metallurgy. Some of the experiments that may be pertbrmed using the miniature

timaace include high temperature solid-state ditthsion experiments, the sintering of technical

ceramics such as alumina, magnesia, zirconia or magnetic ceramics [see reference #1], the

alloying of high temperature metals and glasses, high temperature annealing and heat treating of

materials, crystal growth, thermo-power measurements, and the tabncation of superconductors or

electro-ceramics such as barium titanate or PZT.

45
Safety Precautions

High temperature furnaces are easily destroyed by misuse, and an explosion or fire

hazard exists if incompatible materials are used. Always follow safety guidelines. If

you're not sure about the safety or compatibility of any materials then DO NOT use them

to insulate the furnace or put them in the furnace!

KEEP all furnaces away from anything that is flammable such as wood tabletops,

paper, cloth, or plastic, and never leave the furnace unsupervised. Be sure the area

around the furnace is well ventilated. ALWAYS put the furnace on a bare concrete floor

or other high temperature resistant surface when in operation. Have proper fire

extinguisher equipment nearby and ready to use.

DO NOT open the furnace or lift the furnace when it is operating at high

temperatures. Be sure the core of the furnace has cooled down to below 75°C before

opening or transporting the furnace. AVOID touching heater elements with anything at

all times.

DO NOT put any materials in the furnace that produce flammable or toxic gasses,

including alcohol, methanol, acetone, or any flammable solvents. DO NOT operate the

furnace in the presence of combustible gasses such as carbon monoxide, hydrogen, or

fuel oil. Avoid using metal-chlorides, methyl chloride, any sulfides, phosphates, or

strong alkalis in the furnace, or other compounds that can produce toxic and corrosive or

explosive fumes. Even finely ground organic materials such as carbon, coal dust, or

wood, and many metals are explosive in high temperature air atmospheres. A listing of

hazardous mixtures defined by Group can be found in National Fire Protection

Association document NFPA 497 M.

USE the recommended high temperature electrical hook-up wire to connect heater

elements and be sure that all electrical connections are properly insulated and

mechanically secure before operating the furnace. This experimental furnace operates at

line voltages, and reasonable precautions against the danger of electrical shock must be

observed.

USE high temperature gloves, safety glasses, and other protective clothing when

working around furnaces and other high temperature experiments. As with nearly all

refracto_ ceramic materials, keep any fibers or dust off hands and face, and avoid

breathing any fibers or dust.

The high temperature furnace described in this paper is for teaching purposes only,

and should not be used for any other purpose. The authors of this paper make a diligent

effort to insure the safety of the furnace design and its safe operation. However, due to

the experimental nature of the furnace, the authors cannot be held responsible for any use

or misuse that actually occurs.

Equipment and Supplies

1. "Insboard 2600" ceramic fiberboard available from A. P. Green Industries, Inc., Mexico,

Missouri, USA. The ceramic fiberboard is about $6.69 per square foot and may be

purchased in 2' by 3' by 1" sections. A superior high-density version, "Insboard

2600I-ID" is also available. The maximum recommended temperature is about 1425°C

and the thermal coefficient is 0.17 W/m/°C @ 1095°C.

2. "ECO" Alumina Insulating Board type ECO-20AA, or Premium Grade Alumina

Insulating Board type SALI available from ZIRCAR Products, Inc., Florida, N.Y.

46
Standard samples of 1⁄2" by 2" by 3" boards were obtained from ZIRCAR for the

construction of this furnace. Other required materials include sample amounts of

ZIRCAR Alumina Papers types APA- 1, APA-2. or APA-3 Insulation. Alumina Insulation

type SALI Moldable. and at least 1 pint ofzIRCAR Alumina Cemeni (C4001 AL-CEM),

at a cost of $56.50 per pint. Phone (914)-651-448, Home Page www.zircar.com, e-mail

sales@zircar.com

3. A thermal fuse or thermal cutoff (TCO). The maximum temperature for opening should

be about 220°F. Suppliers include NTE Electronics, Inc., Bloomfield, NJ, phone 973-

748-5089, Www.nteinc.com, and Elmwood Sensors Inc., Pawtucket. RI, phone 800-356-

9663, www.devicelink.com. Cotronics Corporation, Brooklyn N.Y' phone (718)-646-

7996, also offers high-temperature safety products including gloves, clothing, and

emergency fire blankets.

4. A 4-amp slow-blow electrical fuse and inline fuse holder.

5. Silicon carbide heating elements. For this experiment, two "'Norton Crystar Igniter"

elements were used, model 27 !R with 4" ceramic block and 450°C temperature wire.

These model 271R Crystar Igniters were obtained from Norton Igniter Products, Powers

Street, Milford, New Hampshire. The cost is about $21 per igniter element.

6. Thermocouple element. A "'type B" (Pt-30% Rla, Pt-6% Rh) thermocouple wire is

recommended for temperature sensing inside the furnace. Type "B'" platinum

thermocouples with alumina insulators are available in 12" lengths of AWG wire size 30

for about $50.00 (part number XDH-30-B-12) from Omega Engineering, Inc., Stamford

CT, phone (203)-359-1660, FAX (203) 359-7700. Omega Engineering, Inc., supplies a

flee "Temperature Handbook" with a great deal of useful information concerning

temperature measurement, and tables for converting thermocouple voltages to

temperatures.

7. A portable voltmeter, such as the Fluke 87 Multimeter, can be used to read the output

voltage from the "'type B" thermocouple if the voltmeter has a sensitivity of 0.1 milliVolts. The voltage can be converted to a corresponding temperature using tables such as

the ones in the "Temperature Handbook" available from Omega Engineering, Inc.

Handheld thermometers for use with thermocouples are also available from various

sources such as Omega.

8. High temperature heater hookup wire. Teflon-Glass and Silicone Rubber Insulated

Heater Hookup Wire are available from Omega Engineering, Inc., in 25' spools of plated

copper strand. Teflon-Glass 16 gauge or larger wire is recommended. Thisl6 gauge wire

has a temperature rating of 250°C, and has an electrical current carrying capacity of about

10 amps at 200°C including a temperature correction factor of 0.49 (the cost is about

$45.00 for 25 feet). Useful information about heater hookup wire and thermal data for

materials can be found in the "Supplement" or "Heaters" handbooks that may be obtained

free from Omega Engineering, Inc. A line cord capable of safely carrying at least 7 amps is recommended.

9. A commercially available 120 volt (60Hz), 10 amp, 1.4kVA variable autotransformer or

"Variac" is used to adjust the electrical power supplied to the furnace.

10. Simple hand tools including sandpaper, paint brushes, sponges, small spatula, a ruler, a

hacksaw, a scroll saw blade, wire cutters and strippers, tin snips, files, mixing containers

and measuring cups, and a chemical balance should be available.

11. Miscellaneous items include disposable rubber gloves, flexible metal electrical conduit,

sheet metal and materials for building frame for furnace, electrical tape and duct tape, fire

bricks, apron or lab jacket, eye protection, paper towels, plastic bags, a permanent ink

marker, and disposable dust mask.

47
Introduction and Background

One of the most important tools for the materials scientist or engineer is the high temperature

furnace. Many modem engineering materials require temperatures of 1400°C or greater for

processing, and the cost of even a small commercial furnace that is capable of reaching these

temperatures can be $9000.00 or more. In this exercise, a method is presented for building a

simple experimental furnace that is capable of operating at 1400°C (and intermittently at 1500°C),

for a minimal construction cost of about $200. (The actual cost will depend somewhat on the

resourcefulness of the experimenter. ) The cost of the experimental furnace is held at a minimum

by building the furnace on a small scale, and by not using programmable or automatic

temperature controllers (except for an over-temperature indicator or thermal fuse).

Miniaturization of the furnace often may allow the builder to obtain some of the construction

materials on a free sample basis from a generous manufacturer or supplier. The small scale

should also make it easier to operate the furnace safely, provided that good overall safety

precautions are observed.

This miniature furnace can be constructed almost entirely using technical ceramic materials.

The heating elements used for the high temperature furnace are made primarily out of silicon

carbide, an electrically conducting ceramic material. In general ceramic materials have very low

electrical and thermal conductivity, and this is one of the reasons they are frequently used as

insulators. The silicon carbide ceramic heating elements, however, achieve a remarkably high

electrical and thermal conductivity because of nann'al impurities or dopants that are added during

the manufacturing process. Given an adequate amount suitable insulation, the upper temperature

limit that can be attained m the cavity of a typical furnace is set by the heating element that is

used, and the size of the inner cavity. Metal-alloy heating elements have a maximum operating

temperature in dry air of about 1200°C. A layer of chromium oxide forms on the outer surface of

48
riickei-chrome heater wires and protects them from oxidation until rapid deterioration takes place

at the high temperature limit. A typical potte_ kiln will use m-chrome wire heating elements

and will have a useful temperature limit of about 1150°C. Non-metal elements such as silicon

carbide are used to achieve higher temperatures. Silicon carbide elements form a protective layer

of silicon dioxide on the outer surface that allows them to achieve temperatures of a little over

1600°C in air atmospheres betbre rapid deterioration begins. One disadvantage with silicon

carbide elements is the process known as aging whereby the electrical resistance of the elements

increases with continued high temperature use. Higher temperatures cause the aging to take place

more rapidly, decreasing the usefulness of the element.

Energy production needs are strongly dependent on the efficient use of power that is delivered

on a giant scale such as the global production of heating and light, and on a much smaller level

such as the energy "budget" for the miniature furnace described here. Insulating materials play a

critical role in the efficient use of energy. Characteristics of superior high-temperature insulating

materials include low specific heat and thermal conductivity, high resistance to thermal shock,

excellent corrosion resistance, high resistance to oxidizing and reducing atmospheres, high

temperature stability, high mechamcal strength and resiliency, and low health hazard or

environmental impact. There appears to be no existing insulating material that can satisfy, all

these requirements completely. The best available materialS for high temperature furnace

insulation tend to be technical ceramic compositions of aluminum oxide, silica, magnesium

oxide, and stabilized zirconium oxide. These principle ceramic oxides are fabricated in fibrous

"'blanket" forms or stiff boards composed of bonded fibers. Fiber-based insulators, or very

porous ceramics, tend to have high resistance to thermal shock or meehamcal failure due to the

ability of the small diameter fibers to expand or flex when subjected to severe thermal gradients.

Large-scale crack propagation through the fibrous material is suppressed because the fibers

absorb the stress created by differential thermal expansion resulting from steep thermal gradients.

49
-Somedisadvantagesconnectedwithfibrousmsulatorsarehighcost,healthhazardsdueto

respiratory size fibers or dust. and a lack of machinability.

Some of the experiments that may be performed using the miniature furnace include high

temperature solid-state diffusion experiments, the sintering of technical ceramics such as alumina

magnesia, zirconia or magnetic ceramics [see reference #1], the alloymg of high temperature

metals and glasses, high temperature annealing and heat treating of materials, crystal growth,

thermo-power measurements, and the fabrication of superconductors or electro-ceramics such as

barium titanate or PZT.

Design Theory

Silicon carbide heating elements are not sized to a specific wattage output the way many

common metal-alloy wire elements are. The amount of energy that a silicon carbide element is

capable of converting from its electrical power source to heat energy is dependent on the

operating temperature of the furnace and the atmosphere in the furnace. Silicon carbide elements

can operate at higher temperatures in air amaosphere as opposed to reducing atmospheres.

The silicon carbide elements used in this furnace design have a relatively small total radiating

surface area of about 2 square inches. If an ambient furnace temperature of 1400°C is chosen in

an air atmosphere, the "Maximum Recommended Watt Loading" is about 49 Watts per square

inch according to data from I Squared R Element Co., Inc. If the Maximum Recommended Watt

Loading is exceeded, the useful service life of the dement becomes increasingly shorter as the

power input is increased. In any case, temperatures above 1500°C should not be exceeded

because this is the operating limit of the insulating materials and the SiC elements before rapid

thermal breakdown occurs. The radiating surface of each of these elements can therefore supply

about 100 watts to heat the fhrnace cavity at an operating temperature of 1400°C. If two elements

are used then a total of about 200 W is available (two household incandescent 100W light bulbs

require about the same amount of power). This is not much power to drive up the temperature of

the furnace, so the insulation must be very effective!

5O
If the SiC element were in a vacuum, with no energy losses by conduction or convection,

where it could only lose energy by radiative processes (photons or electromagnetic radiation), its

steady-state temperature could be determined from Planck's Law and an energy balance equation.

Given that the SiC element is a close approximation to a "'blackbody" or ideal radiator, then

Electrical Power In = Radiated Power Out

200 W = (Surface Area)oT 4 = (12.9X 10"4m2)(5.67X10 8 W/(m:K4))T _

Solving for the equilibrium temperature of the element gives T = 1010°C. This is the

approximate steady state temperature that a SiC element would reach when radiating freely mto

open space with no heat transfer by convection or conduction. It is possible to achieve much

higher steady state temperatures by surrounding the SiC elements with ceramic insulation, as will

be shown next, and heat conduction through the insulation and inner cavity size will be shown to

be the limiting factors.

Problems involving heat transfer, such as the flow of heat through the insulating walls of a

furnace, often have close analogies with simple electronic circuits and may be analyzed usmg

equations similar to Ohm's Law. The transfer of energy between adjacent parts of matter due to a

temperature difference is called heat conduction. A wall of msulalang material with cross

sectional area A and thickness L whose faces are kept at different temperatures will experience a

flow of heat, Q, perpendicular to the faces in a time t. The temperature difference between the

faces of the wall corresponds to the potential difference across an electrical resistance, and the

heat flow, H = dQ/dT, corresponds to the flow of charge through an electrical resistance. The

thermal conductivity, k, of the insulation wall corresponds to the inverse of electrical resistance.

The fundamental law of heat conduction is H = -kAdT/dL, where H is measured in Watts/°K/m if

SI units are being used.

Insulating materials are most critical m the core of the furnace. The goal in this design was

intermittent operation at 1500"C and extended operation at 1400°C. Most importantly, the inner

insulation walls must have sufficient chemical and thermal stability to withstand temperatures of

51
at least 1600°C, and after this condition is met, the thermal conductivity of the material should be

as low as possible. A practical compromise between cost and performance appears to be "'ECO20AA Alumina Insulation Board" manufactured by Zircar Products, Incorporated. "ECO-20AA"

refractory board is made with high purity alumina fibers and contains alumina powders that act as

a cost reducing filler matenal.

The graphs of thermal conductivity as a function of temperature shown for "ECO-20AA"

high temperature insulation in Figure I, and "Insboard 2600" back-up insulation (A. P. Green

Industries, Inc.) in Figure 2, were generated by fitting curves to some data obtained from the

manufacturers at specific operating temperatures. The thermal conductivity of a material tends to

increase in a non-linear way with increasing temperature, and this phenomenon can make heat

flow calculations significantly more complicated. It so happens that the thermal conductivity of

the insulating materials selected in this particular design mcrease in a very linear way with

temperature over the operating range, as shown in Figures 1 and 2. The thermal conductivity of

ECO-20AA can be described very well by the linear equation k_(T) = ot_ + 13_T,where cq = 0.03

and 131=I .5X10 "4. In a similar way, the thermal conductivity of"lnsboard 2600" is described by

k2(T) = tx2 + 132T, where ct2 = 0.04 and 132=1.17X10-* .

An estimate for the heat flow through the walls of a cubical container (or furnace), and the

resulting equilibrium temperature within the inner cavity, was derived by noting that the surface

area of a cube is 6(2L) 2 (where 2L is the length of one side of the cube), and then integrating with

respect to the heat flow equation. The result is

HI = (cq(T1-T2) + [3t(Tl2-T22) / 2 ) / RI

where T_ is the temperature on the inner wall surface and "1"2is the temperature on the outer wall

surface of an insulation layer with thermal conductivity, kj(T) = ctl + 13iT. Rt is the "thermal

resistance" of the insulation layer and is given by

Rl = (L2 -LI)/(24LtL2)

52
WhereL_isthe distance from the center of the cubical furnace to the inner surface of the first

insulation layer, and L2 is the distance from the center of the furnace to the outer surface of the

first insulation layer.

It is cost effective to construct the inner insulation layer with the high temperature "'ECO20AA" material, and to use an outer back-up layer of the less expensive "l_nsboard 2600"

insulating board. The total thermal resistance is given by Rt + R2, where R2 follows from the

relation for RI in a logical way, R2 = (L3 -L2)/(24L2L3). The heat flow through the inner

insulation layer is therefore Hi = (ctl(Ti-T2) + _I(T12-T22) / 2 ) / RL, and the heat flow through the

outer backup layer is H2 = ((x2(T2-T3) + _H(T22-T32) / 2 ) / R2 where Ta is the temperature of the

outermost surface and T2 is the temperature at the interface of the inner insulation layer and the

back-up insulation layer. Given steady state heat conduction, the heat flow will be constant across

each layer of insulation and H) = H2 = H or

H = (oq(T1-T2) + [31(TI2-T22)/ 2 ) / Rl = (_2(T2-T3) + [32(T22-T32)/ 2 ) / R2

An iterative, or "trial and error", technique was used to solve this system of equations using

some practical values based on the available stock material sizes and the design goals. The size

of the inner cavity was chosen to be a 2 inch cube with an inner cavity temperature of 1500°C and

the temperature at the surface of the outermost msulahon layer was set at 4 l°C, (a value near

room temperature.) The thickness of the inner "'ECO-20AA" insulation wall was fixed at 1⁄2" and

the thickness of the outer "Insboard 2600" layer was fixed at 2". This gives TL = 15000(2, T3 =

41°C, L_ = 1.0 inch, L2 = 1.5 inches, and L3 = 3.5 inches. It was found that these design goals

were satisfied when only 175 Watts of input power from the SiC heating dements was available.

The temperature was "1"2= 1072°C at the interface between the "ECO-20AA" and the "Insboard

2600" insulation layers, and k_avg= 0.2362 W/°C/m for the "ECO-20AA" insulation and k2_v8=

0.1106 for the "Insboard 2600" layer. The temperature at the interface, T2 = 1072°C, is safely

below the 1425°C maximum service temperature of the outer "lnsboard 2600" material, and the

53
loyal input power of 175 Watts is close to the Maximum Recommended Watt Loading for two

SiC heating elements. In actual practice, 175 Watts of input power will probably not be enough

to produce an inner cavity temperature of 1500°C due to significant heat losses that are not

accounted for (such as the flow of heat out through the dense ceramic blocks and electrical leads

that are connected to the SiC heating elements.)

Construction Details

Figures 3 and 4 give approximate dimensions of the insulation layers and placement of

components for the experimental furnace. The walls of the inner cavity are first constructed out

ofZircar "ECO-20AA" or "SALr' type fibrous insulating board. The walls of the inner cavity

should be completely lined with at least 1⁄2" thickness of one of these high service temperature,

high purity alumina insulating boards. The high temperature msulation board can easily be cut by

hand with a hacksaw blade and joined using Zircar Alumina Cement (C4001 AL-CM) to form a

hollow cube with a 2" inner dimension and a 3" outer dimension. The total volume of the

inner high temperature cavity will be about 8 cubic inches for firing samples. Be sure to

wear a dust mask and protective clothing when cutting or shaping any of the insulation

materials in this experiment. The Zircar Alumina Cement is applied to the surfaces to be

joined, and the joined parts must be allowed to dry for about I day before moving or

placing into service. Zircar Bulletin #ZPI-306 for Alumina Cement gives important

application instructions, and should be read before beginning construction. The top

section of the inner insulating cube is cemented to the furnace "Lid" as shown in figures

3 and 4, and NOT to the rest of the inner cube, so that the "Lid" can be removed to insert

or remove the sample to be fired. The inner surface of the insulating cube is lined with

Zircar Alumina Paper type APA-I, 2, or 3 to create a protective barrier. One side of the

APA-1, 2 or 3 Alumina paper is given a brush-coat with Alumina Cement and then

54
-pressed onto the inner cavity surface. Narrow 1/8" vertical slots are cut in opposing walls

of the 1⁄2" thick high temperature insulation so that the black silicon carbide elements of

Norton 271R "hot surface i_iters" can be inserted into the inner cavi .ty (see fimu'es).

The silicon carbide element should be about 1/8" away from the closest parallel

insulation wall, and approximately centered vertically in the cavity (see fimu'es 5 and 6).

The inner high-temperature insulating cube is enclosed with 3 layers of 1" thick

"Insboard 2600" back-up insulation. All 90-degree joints between insulating boards are

brush-coated and joined with Alumina Cement, and all edges including cross-cut surfaces

of the insulating boards are also brush-coated with Alumina Cement. The Alumina

Cement should be used to strengthen all edges because they are subject to crumbling, and

the cement greatly reduces the amount of fiber or particles that can be given offby the

insulation materials. Avoid completely coating the faces of the insulating boards in order

to reduce the amount of Alumina Cement that is required, and so that the thermal

conductivity of the insulating boards is not increased by the relatively low thermal

resistance path created by the cement. Two exceptions are the inner surfaces of the

furnace "Lid", and upper surfaces of the furnace that are in contact with the "Lid", where

a solid coat of Alumina Cement should be applied. Holes for the 4" long ceramic block

part of the Norton 271R heating element may be cut in the "Insboard 2600" insulation

using a drill bit and a scroll saw blade. Cut a thermal gasket out of the high-purity

alumina insulation paper that is about 1⁄2 inch by 3/_,, with a slot in the middle that is big

enough to push through the SiC meander element. Push the alumina paper gasket down

the SiC meander until it covers the face of the ceramic insulating block. Gently insert the

Norton 271 Elements with the alumina paper gasket in place until the alumina paper

55
-gasket is compressed between the ceramic block and the outer wall of the innermost (high

temperature) insulation layer. The SiC meander should protrude through the narrow 1/8"

slot in the inner insulation wall into the open furnace cavity as depicted in figures. Any

open insulation gaps that occur around the Norton 271R heating elements or at other

joints should be filled or repaired with Zircar "SALI" Type Moldable Alumina

Insulation. Use a light coat of Alumina Cement between the outer insulation wall and the

Norton 271R heating element to hold the element securely in place. Too much Alumina

Cement will make it difficult to remove and replace a damaged heating element. The

"type B" platinum thermocouple is inserted with a solid alumina insulator down through

the middle of the "Lid" and the bare thermocouple should extend slightly down into the

inner cavity. The Norton 271R heating elements are connected in parallel (using 16

AWG high-temperature heater hook-up wire) to the output of an auto-transformer or

"Variac". The output voltage of the auto-transformer is adjusted manually by the

operator to control the electrical current through the silicon carbide heating elements, and

thereby the temperature of the furnace. Be sure to electrically and thermally insulate all

connections well, and the line cords must be able to carry at least 7 amps safely. Place a

4-amp slow-blow electrical fuse and fuse holder m the electrical line between the output

of the auto-transformer and the parallel connection to the heater elements. The 4-amp

fuse should limit the total current flow to both heater elements so that the cavity

temperature remains less than about 1500 C. Temperatures greater than about 1500 C

may cause the ceramic insulating block that holds the SiC heater element to melt and

decompose the surrounding insulation! Place a thermal fuse or thermal cut-off (TCO) in

contact with the outside center of the furnace insulation floor to be used as an over56
temperature sensor in the event of a malfunction. The case of the TCO can be pressed

between the outside insulation floor of the furnace and another layer of suitable soft

insulation such as left over sections of the 2' by 3' sheet of"Insboard 2600" insulation.

The TCO is a non-resettabie fuse, and if the outer temperature of the furnace becomes too

high because of melting or decomposition of the inner furnace insulation, the TCO should

open and stop the flow of electncal current to the heating elements. The TCO must be

electrically connected in series with both the Norton 271R heating elements. Thermal

cutoffs are commonly used for protection in appliances such as hot plates, or irons, and

they are available from many sources such as Elmwood sensors, Inc., and NTE

Electronics, Inc., (see the equipment and supplies section. ) The maximum temperature

for opening for the TCO should be around 220°F, and the walls of the furnace should stay

below this temperature, except for the area around where the ceramic blocks of the

heating elements protrude from the furnace sidewalls. Consult with the manufacturers

applications engineer for the exact TCO model type and current prices before ordering.

It is highly recommended that the furnace be enclosed in an electrically conductive

metal case before operation. The metal case can be made using sheet-metal aluminum or

steel joined at the edges with bolts or fastened to a rigid metal frame. Standard electrical

conduit hardware can be used to cover the terminals of the heater elements, and

connecting wires should be well insulated and fed through flexible metal conduit between

the heater elements (see Figure 6). Electrical line going into any metal case should be

properly strain-relieved at the entry point. Standard safety practice requires that a secure

electrical ground connection be made to the metal case.

Testing and Operation of the Experimental Furnace

57
Place the furnace on a non-conducting fire-resistant surface, such as a concrete

building floor. Increase the power to the heating elements slowly while monitoring the

cavity temperature with a sensitive voltmeter and the "'type B" thermocouple. It should

not be necessary to apply more than about 70 volts (or more than about 4 amps) to the

heating elements in order to reach steady state temperatures well above 1400°C in the

furnace cavity. The outer surface of the furnace should be below 220°F at all times

during operation (the ceramic heater element blocks and the area surrounding them will

run at higher temperatures because of the relatively high thermal conductivity of the

dense ceramic blocks. The insulation used to construct this furnace contains organic

binders that will smoke or out-gas during "'burn-out" when the furnace is operated the

first time or two at high temperatures. When a voltage of about 57.5 volts was applied

across both heater elements, a current of about 1.54 amps flowed in each element (total of

3.08 amps), and our experimental furnace reached a steady state temperature of about

1400°C, (a voltage of about 8.7 millivolts across the type B thermocouple.) This is a total

input power around 177 watts. This value appears to be higher than our theoretical

prediction, probably due in large part to heat losses through the ceramic blocks of the

silicon carbide heating elements and the relatively high thermal conductivity of the

Alumina Cement that was used to construct the furnace.

Acknowledgements

The authors wish to acknowledge the partial support of the National Science

Foundation's Advanced Technology Education Grant No. DUE:ATE 9602360, The

Materials Aspects of Manufacturing Technology Institute Program.

REFERENCES

58
1. "Properties of Magnetic Femte's With a Simple Fabrication Method", by Luke Ferguson and

Thomas Stoebe, National Educators' Workshop Update 97, November 2-5, 1997. NASA

Conference Publication NASA/CP- 1998-208726.

Figure Captions.

Figure 1. Thermal Conductivity ofZircar "ECO-20AA" Alumina Insulation Board.

Figure 2. Thermal Conductivity of A. P. Green Industries "Insboard 2600" Insulation.

Figure 3. Top View of the Experimental Furnace and Furnace "Lid".

Figure 4. Side View of the Experimental Furnace and Furnace "Lid".

Figure 5. Experimental Furnace with "Lid" removed to show Norton 271R silicon

carbide element inside Furnace cavity (metal case not shown).

Figure 6. Auto-transformer, voltmeter, Norton 271R silicon carbide heating element, and

Experimental Furnace with "Lid" in place for operation.

59
Thermal Conductivity "Zircar ECO-20AA"

,/

0.28

0.26

0.24

0.22

0.2

018

016

0.14

0.12

0.1

0.08

0.06

0.04

200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 15001600

Temlxrature (Centigrade)

Figure 1. Thermal Conductivity ofZircar "ECO-20AA" Alumina Insulation Board.

e_

0.2

018

0.16

0.14

012

0.I

0.08

0.06

004

0.02

0

Thermal Conductivity. "Insboard 2600"

i / ,

, l

L

I r

r

0 100 200 300 400 500 600 700 800 _00 1000 1I00 1200 13001400

Tempera_re (Centigrade)

Figure 2. Thermal Conductivity. of A. P. Green Industries "'Insboard 2600" Insulation.

6O
•o- 3"

i

7"

i ;r

4

Lid

"Type B"

platinum thermocouple

t i

i,

_f

1" thick -,.-

/

INSBOARD "-2"

2600 _ _"''"_ ---.I.

fJ

112" thick

ECO-20AA

J

J

r

i

8" !

I

t

4"

I

:"_---2 1_2"---_

p

[

I

n

v,

,. Furnace

--I.-_

Figure 3. Top View

61
\

"Type B"

z platinum thermocouple

Lid

1" thick .._._

INSBOARD I- --_

I_'_ 9 _ I

4

8- Furnace

k

_ 112"thick

ECO-20AA

Figure 4. Side View

62
Figure 5. Experimental Furnace _vith "Lid" removed to show Norton 271R silicon

carbide element inside Furnace cavity. (metal case not shown).

Figure 6. Auto-transformer, voltmeter, Norton 271R silicon carbide heating element, and

Experimental Furnace with "'Lid" in place for operation.

63

TEACHING STATISTICAL QUALITY CONTROL

AND PROCESS ANALYSIS IN

MATERIALS LABORATORY

Neda S. Fabris

Mechanical Engineering Department

California State University, Los Angeles

5151 State University

Los Angeles, California 90032

Telephone 213-343-5218

e-mail nfabris@calstatela.edu

65
Neda S. Fabris

66
TEACHING STATISTICAL QUALITY CONTROL AND PROCESS

ANALYSIS IN MATERIALS LABORATORY

Neda S. Fabris, Ph.D.

Professor, Mechanical Engineering California State UniVersity,

Los Angeles, California

Key Words: Statistical Process Control, Standard Deviation, Machine Capability,

Process Capability, Natural Tolerance Limits (+ 3_) and Six-Sigma Productions.

Prerequisite Knowledge: basic graphing, use of micrometer, basic algebra,

Desirable Knowledge: a) understanding of manufacturing processes, b) normal

distribution, c) standard deviation

Objective: To introduce engineering students to Statistical Quality Control,

Statistical Process Control, Machine Capability Indices: Cp and Cpk

Equipment:

1. micrometer for each student or group of students,

2. 20-30 tensile test specimens (or any other machined round bars)

3. graph paper

4. calculator

INTRODUCTION:

Today's modern industry, in its quest for improved quality and customer

satisfaction, expects engineers to understand and implement statistical process

control charts and methods in every step of their activities, from material selection

to the design and manufacturing of new products.

On the other hand, most engineering students are not introduced to practical

applications of statistics even if they have a class in probability and statistics. This

class is usually taught by professors from the mathematics department and focuses

on the probability and fundamentals of statistics. Even if it is taught by

engineering professors, the majority of them are not familiar with the difference

between statistical quality control and statistical process analysis. In order to

introduce students to the practical application of the statistics and to prepare them

for the modern industrial environment, I have developed a laboratory exercise,

described below. This lab is part of the first experiment in the Engineering

Measurement Laboratory, a required course for all juniors. In addition to this

concept students are introduced to measurement techniques and the general

characteristics of the measurement instnunents.

67
In order to help students learnnew materialsthe definitionsof the new concepts

arc given in the hand-outs.

METROLOGY LABORATORY, STUDENT HAND-OUT

1. BACKGROUND MATERIAL

Definition of Ouality and Statistical Tools.

Quality assurance is the total effort of the manufacturer to ensure that its product

conforms to a detailed set of specifications and standards.

These standards cover severalparameters,such as dimensions, surfacefinish,

tolerances,color,mechanical, chemical and physicalproperties[l]*.

Today's companies work on the premise that quality cannot be inspected in the

product but must be built into the product. This means you have to build quality

products from the first step, not just separate good product from bad at the end of

the cycle, using some measurement and inspection method. This approach

requires that particular quantities are measured and inspected after each operation

(for example, diameter of the part) and then if necessary, machine adjusted to

produce a satisfactory part.

However, one hundred percent inspection in mass production is too costly and

time consuming, so industry relies on statistical quality control, i.e. the

measurement of the given quantity of the sample of products to determine the

quality of the total production.

After the measurement of the given property the following charts are drawn [2] to

analyze the process (or machine):

• ,_chart. Average measured value, or mean, of a certain quality (or quantity)

for each of a series of samples taken from the production process. It indicates

how the process mean varies over time.

• R chart. In this chart, the range of each sample is plotted. For example, the

difference between the diameter of the smallest and a larger part in the sample

of parts with the same nominal diameter.

• p chart. This chart is used to plot the percentage of defective parts in the

sample (this includes parts whose sizes are outside the tolerance limits). If the

percent of defective parts suddenly increases the process is outside of

statistical control.

• c chart. Here the number or count of defects in the sample are plotted as a

function of time.

Dimensional Tolerances is defined as a permissible or acceptable variation in the

dimensions of the part.

• Number in [ ] represent references on the end of the article.

68
Standard deviation or c [3] for the sample is given by equation (1):

Af" N

Where x =

ix, +x 2 +---+xt¢ )

N

(1)

(2)

Natural Tolerance Limit,_

To be successful in today's competitive environment, companies have to produce

parts whose defect rate is minimal, i.e., at least + THREE SIGMA of the products

have to be defect-free. In case of dimensions, this means that SIX-SIGMA of the

products have sizes between UPPER SPECIFICATION LIMIT (USL) or upper

tolerance and LOWER SPECIFICATION LIMIT (LSL) or lower tolerance. In

that case, machine capability potential index, Cp = 1; where Cp is defined as

Cp=[(UPPER SPECIFICATION LIMIT)-( LOWER SPECIFICATION limit] /

(MACHINE CAPABILITY) = (USL-LSL)/+ 30 (3)

If Cp is equal to 1, the process centered on the mean on the machine has the

potential to consistently manufacture a conforming product, provided that the

process does not drift, or there is no increase in the machine's inherent variability

due to wear and tear. Value of + 3 c are called natural tolerance limits for the

given machine. This is shown in Figure 1.

UCL

I

_! I _ "i g 0.135%

|

-:Is -ls _" ÷le +2s ÷:Is

! i

95.44% L

- gg.7"J_ -, _

A+B,, 0.27%

el

TOTAL • 100.00%

WHERE= UCL " UPPER

CONTROL LIMIT

LCL

-,,311

Figure 1. Normal distribution for Cp = 1

LCL - LOWER

CONTROL LIMIT

69
To compensate for the equipment wear and tear, quality conscientious companies

today have even stricter requirements, i. e., they want the Cp to be 1.33, which

means + 4c_ of products have to be defect-free or have dimensions between the

given tolerance limits.

If a company has achieved Cp = 2, it is called a Six-Sigma quality program [4].

This means that + 6¢L (or totally 12t_ of products) are defect-free or lie between

USL and LSL. For example, Motorola, Inc., is a Six- Sigma company, and for its

quality accomplishments it received in 1989 the very prestigious Malcolm

Baldrige National Quality Award.

Students can appreciate the 6c_ quality on the following example:

Quality of "3or" (or Cp =1), process means:

2,700 defects per million parts, or

1.94 hours duration of power outages per month or,

1.35 misspelled words per page.

Quality of "'4¢_", (or Cp =1.33) process means:

63 defects per million parts, or

2.72 minutes duration of power outages per mon_ or,

l misspelled word per 31 pages.

On the other hand "6a", or (Cp =2)process means:

0.002 defective parts per million or,

0. 005 seconds of power outages per month or,

one misspelled word per small library!

Machine Capability_ and Machine Performance

Often the project is approached is a different way: the capability of the particular

machine or process is determined by,

• measuring the dimensions, defect-free output, or some other characteristics of

all the parts or a representative sample of the parts produced.

• Using these values, the + 3 a of the production is computed and, in the case of

dimensional measurements, the tolerance limits are determined. In a machine

these limits represent machine capability. In a process, tolerance limits are

determined for all parts produced in the shop on similar machines, (for

example, a lathe) and they determine the so called process capability.

• Using Cp = 1 (or Cp = 1.33) the USL-LSL is computed. These limits are then

called natural tolerances of the machine (or process). If the difference

between upper and lower tolerance assigned to the part in the design

process is equal or larger than USL-LSL, this machine (or process) can

be used to produce the product. For example, ifUSL-LSL for the given

machine is 0.005 in., you can produce satisfactorily the parts with tolerances

7O
equal or larger than that value. If in this case, the design requires the

difference between the upper and lower value (i.e., tolerance range) of the part

dimensions to be 0.001 in, you should look for the more accurate machine, or

choose a different process (for instance grinding instead turning)! Otherwise

you will have too many defective parts, whose sizes are too small or too large.

If the process is not symmetrical with respect to the nominal value, instead of Cp,

Cpk is used where Cpk is the machine performance index, and is defined as the

smallest value of two Z's, i.e., Z,_,. where Zt and Z2 are defined as:

Zl = (Mean value-LSL)/3cr (4)

Z2 = (USL- Mean value)/3or (5)

Mean value is defined as the algebraic sum of all measured values divided by the

number of specimens.

Cp and Cpk are equal if the process is centered on the nominal value of the part.

The relationship between Cp and Cpk is given in Fig. 2.

Cp AND Cpk RELATIONSHIPS

Cp = 1.0

Figure 2. Normal Distribution for Cp = 1 and different Cpk'.

2. DATA SHEET

1. Using the given micrometer, measure the diameter of the given specimens in at

least three positions (diameter earl be different in the middle cross-section than on

the end, due to the bending of the part during the cutting process). Find the

average measurement for each part. Measure all other dimensions.

2. Sketch your specimen with all dimensions.

3. Draw the statistical distribution of the whole batch (all given parts), i.e., the

frequency of the occurrence of each measured diameter.

71
3. REPORT

1. Compute the standard deviation (c) for the given sample of parts.

2. Using Cp or (Cpk, if applicable) determine the NATURAL TOLERANCES OF

THE MACHINE (assume all parts are machined on the same machine).

3. Determine the maximum part tolerances that can be machined on that machine

so that the quality of the production is Six-Sigma.

4. Compare these tolerances with ones computed using 30 quality production.

5. Assume that each day only two specimens are machined at the same machine.

Take two specimens from the batch given. Draw _( and R charts for this

production.

6. Explain the steps involved in manufacturing of the specimen: the machines and

processes used.

7. Explain what is the reason for the variability of the sizes of the product, i.e., the

difference in the measured diameters, and what can be done to decrease natural

tolerance limits of the given machine.

8. Imagine that you have two machines: one is producing parts whose mean is

equal to the given nominal value but the natural tolerances are large, other is

producing parts whose mean value is different then nominal but natural tolerances

are small. Which one, in your opinion is better machine? Explain your reasoning.

REFERENCES:

1. Johnson R.A., "'Miller& Freund's Probability & Statistics for Engineers ",

Filth Edition, Prentice-Hall, Inc. 1994

2. Groover M.P., "'Automation, Production Systems, and Computer-Integrated

Manufacturing", Prentice-Hall, Inc. 1987

3. Grant L.E., "'Statistical Quality Control", Sixth Ed., Mc.Graw Hill, Inc. 1988

4. McFadden F.R., "'Six-Sigma Quality Program '" Quality Progress, June 1993

Neda Fabris, is Professor of Mechanical Engineering Department at California State

University Los Angeles (CSULA). She has B.S. Degree from University of Sarajevo,

Bosnia and Herzegovina, and M.S. and Ph.D. from Illinois Institute of Technology in

Chicago Ill. She was a Member of Technical Staffat Bell Telephone Laboratory,

Member of Research Staff at Technical University in Aachen, Germany, and has taught at

the University of Sarajevo, at University of Illinois, and at CSULA (from 1979 till

present). She served as a Chair of Mechanical Engineering Department from 1989-1993.

Her research is in manufacturing material and pedagogy of teaching.

72
SYSTEM UPGRADE OF ATOMIC OXYGEN

GENERATOR FOR SPACE MATERIALS RESEARCH

Kyo D. Song

Department of Technology

Norfolk State University

2401 Corprew Avenue

Norfolk, Virginia 23504

Telephone: 757-683-8105

e-mail kdsong@vger.nsu.edu

Bruce Budde

LARSS Student

New Mexico State University

and ' _

Carolyn Hamilton

LARSS student

University of New Mexico

73
I

Kyo D. Song

74
System Upgrade of Atomic Oxygen Generator

for Space Materials Research

Kyo D. Song, Professor, Department of Technology, Norfolk State University

Bruce Budde (LARSS) student, New Mexico State University

Carolyn Hamilton (LARSS) student, University of New Mexico

Keywords:

Atomic Oxygen, Space Materials, Erosion, Kapton, RF Generator

Objective:

This experiment provides a simulation capability for materials erosion of spacecra_ in

natural space environment (NSE) at low earth orbit(LEO).

The student will learn from the experiment to:

1. Understand significant composition of gas species in the LEO.

2. Understand interaction mechanism of atomic oxygen (AO) with space materials, such

as Kapton and Mylar films.

3. Setup a mass spectrometer into the AO system.

4. Conduct experiment and monitoring the AO system with a mass spectrometer.

5. Find the fractional dissociation of molecular oxygen from the system.

6. How can the AO system be upgraded in terms of AO flux density and energy?

Abstract

An effort to upgrade an Atomic Oxygen (AO) system, that has a flux level of 3.5 x

10 t5/crn2s at 0.04 eV energy at NASA Langley Research Center was made to increase the

level of flux and energy by at least one order of magnitude. The upgrade includes a new

installation of an erosion monitoring system. The present capability of the AO system was

not fitted to simulate the conditions of a lower orbit environment where the energy level

of AO is 4 eV. The flux density increment is favorable for a short exposure time. In order

to improve the physical parameters such as the AO flux density and the energy, input

power of the RF generator, flow-rate and pressure have been changed. As result, AO flux

density is increased to 19 times (5.01 x 1016/cm2/sec) and the energy has been increased

to 25 times (1 eV) at 1.0 SCCM flow-rate. The higher efficiency operation of the system,

however, was obtained at 0.4 SCCM of the flow-rate. At 1.6 SCCM flow-rate, however,

there were no dissociation or glow observed.

The upgraded system has a capability to provide real-time mass information such

as impurity, vacuum status, and erosion rate of space materials. LARSS (Langley

Aerospace Research Summer Scholars) students have collected the detail experimental

data in 1997 and 1998.

75
I. Introduction

Atmospheric composition

The composition and number of density of the atmosphere are function of altitude,

local time, sunspot activity, solar flux, magnetic index. Neutral species present at Low

Earth Orbit (LEO) include O, N2, 02, He, At, and I-L Molecular nitrogen is the dominant

below 200 kin, whereas atomic oxygen dominates above 200 kin. As one would expect,

the number densities of neutral species decrease with increasing altitude [1].

The atomic oxygen density at 300 km is the 109/cm 3 corresponds to the density of

residual gas in a room temperature vacuum chamber at 10"ytorr as tabulated in Table 1.

However, the higk velocity of spacecraft in the altitude causes the atomic flux density on

an exposed spacecraft material to be quite high as 1015/cm2/sec. Assuming a spacecraft in

orbit at 300 kin with a velocity of 8 km/sec is subjected to oxygen atoms that are

condensed upon the surface, a monolayer would form every second [1]. The kinetic

energies of 8 km/sec for N2, O and He particles are approximately 9.3, 5.3, and 1.3 eV,

respectively. The physical parameters at the 300 km altitude is tabulated in Table 2.

Background

The previous AO system has been relayed on material erosion test by measuring

of Kapton loss. This measurement did not provide any information of the causes for the

material erosion. The previous system consisted of a RF generator, an UV lamp, and a

test chamber. A RF generator with associated tuning circuits provided up to 100 W of

power at 13.5 MI-Iz. The chamber pressure was controlled by the internal vacuum pump

in the range of 20 - 100 retort. The flow controller was set by 0.16 SCCM at the 13 psi

gage pressure. From the previous parameters for the IAO sys_.m, 0.04 eV of the atomic

oxygen energy, 3 x 1015/cm 2 sex of the flux density, 1 x 10Wcm" of the density, 0.11

W/cm 3 of the power density, and 1.1 x 10"° W/molecule were obtained as described in

Table 3. At the 20 mtorr of the chamber pressure, the average spacing between atoms is

0.1 pro, and the mean free path is to be 1.64 ram. The natural frequency of collision per

molecule is calculated to be 0.3 MHz that should be much smaller than the applied

frequency used (13.5 MHz) to have more collision.

To increase AO flux density and the energy, available parameters such as input

power of the RF generator, flow-rate and pressure need to be changed. The following

section will be described the experimental details for the upgrade of the AO system.

76
II. Experimental Setup

The experimental system consists of a Lockheed Oxygen Plasma apparatus

(OPA) and the Dycor Quadrupole Mass Spectrometer (QMS) as show in Fig. 1. The mass

spectrometer is connected to a PC computer using the Dycor System 1000 interface card

(DyCard) with associated software (presently state of the art).

The OPA contains a RF generator and an ultraviolet light (UV) to test materials

exposing to atomic oxygen (AO) and/or the UV as shown in Fig. 2. The RF chamber is a

5 cm ID x 15 cm long quartz chamber with a 1.27 cm aperture at one end opening to the

UV and sample chamber, which is a 7.62 cm ID x 17.8 cm long quartz chamber. The

sample is placed in the chamber at 30 degrees to the oxygen plasma flow. The maximum

allowable size for specimens is 2.5 in wide x 4 in. long.

The oxygen supply in the original configuration was furnished through a manual

leak valve that was set by 10 std. cc/hr (0.167 SCCM) at l0 psi gauge pressure. This

system has been modified so that the flow-rate and supply pressure can be adjusted to

provide the desired test parameters in the range 10 -100 cc/hr and 36 psi gage pressure

respectively. By altering the oxygen flow-rate and RF power the maximum atomic

oxygen flux density and the energy can be found as well as optimum conditions of the

dissociation of atomic oxygen.

It has been discovered through testing that only research grade oxygen of

99.999% purity or above should be used. Reducing impurity at the chamber is a critical

factor based on the leak rate of the system and contamination of the system to get

qualitative data during experiments. Typical signal/noise ratio which was generated from

the impurity was 1,000 during the experiment.

R.F. power is generated up to 100 W at 13.56 MHz. The oscillator conservatively

set at 50 watts forward power with minimal reflected power. To obtain a nominal flowrate of 3 x 1015 A0/em2/sec a Tesla wire is connected at the high potential electrode on the

RF generator tube and attached to the exterior of the sample tube. No termination is

necessary at the sample tube.

The OPA is connected to the Mass Spectrometer by means of

interconnecting vacuum chambers. Separating the two vacuum chambers is a copper

gasket with a center aperture of 0.0135 in. The OPA and test chamber maintains a

vacuum of 10 .3 ton" while the chamber connected to the mass spectrometer maintains a

very high vacuum of 10 "7.

The high vacuum section is constructed of stainless steel to minimize the effects

of out gassing from the system. A gate valve separates the two vacuum chambers

isolating the entire high vacuum section during sample insertion also permitting the

chamber to retain vacuum pressure as shown in Fig. 1.

77
The analyzer head and vacuum chamber were baked up to maximum temperature

of 350 °C before any experiments were nan. The entire system was then allowed to run for

two hours, allowing the AO and QMS to stabilize the mass signals before any data was

collected.

The electrometer is connected directly to the analyzer head in order to obtain the

best signal to noise ratio. The quadmpole control unit and computer are connected to the

electrometer power supply and allowed to select a unit by means of an A/B switch. This

allows for a backup of the system, control and data collection systems, if at any time the

computer system should fail, as well as allowing for the calibration of the two control

systems.

The advantage in using the computer over the Dycor control unit is that allow for

more flexibility in the collecting of data. The data can be obtained in real-time and/or

saved in a digital format as a computer file as well as having the ability to set a schedule

for determining just when data is saved during the experiment.

The computer software also provides for the use of macro commands to automate

the collection of data as well as setup of different modes of operation and configurations

for viewing the data. This includes such modes as Analog, Bar Trend, Meter,

Annunciator, Tabular, Library, and a custom mode which includes either a single mode

display window or multiple mode display windows as well as display the parameters.

The software schedule option allows for the control of the scanning operations in

either continuous or discrete modes and triggers the running of macro files (which allows

for the automation of a series of commands) within the selected time intervals.

The Macro commands allow by the software include: saving data, turning the

filament on/off, turning the scan on/off, loading of system files, renaming of files,

transferring files, print commands, message text and error massages.

A glass rack was used to allow samples to be mounted inside the test chamber.

Samples (Du Pont Kapton) used were cut into 1.5 cm by 4.0 cm, weighed prior to being

placed in the chamber. To compare with the results from mass spectrum and Kapton

weight-loss measurement the samples exposed to the AO plasma. After exposed the

samples for two hours the samples were removed from the test chamber and re-weighed

to determine the net weight loss.

An AO fluence and flux density could then be determined as follows. The

influence (F1) is calculated as

F1 = A(cm 2)p(gr / cm3)R(cm 3 / atom)

(1)

78
where, Am denotes the mass loss, A is the area of the material p denotes the sample

density and R is the reactivity (3 x 10 .24 cm3/atom). The atomic oxygen flux (F2) is shown

equation (2) as

F2 (AO / cm 2 sec)=

F 1(AO / cm 2 )

t(sec.)

(2)

where, t denotes the exposure time in seconds.

Preparation of Experiment

For a measurement of reliable data, pre-experiments were needed to verify the

impurity level of the system, stability of mass spectrum and limitation of the system. A

typical base spectrum was measured as shown in Fig. 3. As shown in the figure, the

partial pressures of water vapor, He gas are approximately 10 -9 tort level while others

showed in the range of 10 -1° torr. The partial pressure of oxygen as a dominant species is

in the range of 10 -6 torr that indicates the s/n ratio is about 1,000 as neglecting impurities

contained in the oxygen bottle.

Dwell time determines the scanning speed and the degree of background noise. In

order to find the optimum dwell time, a base mass spectrum is measured in function of

dwell time. As the result, the mass spectrum of various gas species shows some loss of

the information at the dwell time of 120 reset. Based on the observation, a reliable mass

information can be found at the 500 msec dwell time.

With a Kapton specimen loaded at the test chamber a mass spectrum is also

measured with 1.0 co/hr, of the flow-rate at 50 W RF power as shown in Fig. 4. In the

spectrum, ammonia, methane and carbon as a byproduct from the Kapton were

significantly showed. This indicates there is a process for erosion of a Kapton material.

There may be a correlation between the erosion rate and time integration of mass

spectrum for some products.

III. Results and Discussion

In order to understand what physical and chemical effects may arise from

atmospheric atomic oxygen etching on spacecraft materials, ground facility needs to

simulate the condition as close as possible. Some of important physical parameters were

79
calculated based on the measurements. The most probable velocity, Vmp, of particles

leaving the RF source is

( 3kT.]2 Vmp= --m--) (3)

where, m is the particle mass, k is Boltzmann's constant, and T is the absolute

temperature. In order to obtain atomic oxygen at 8 km/sec, such a source must operates at

over 5.3 eV which is corresponds to 40,000 K.

In study of atomic oxygen experiment, many researchers [3-7] used other gases

such as He, Ne, N2, Ar and their combination to generate more energetic atomic oxygen

due to more collision between molecules. However, inclusion of other gases is not valid

to study for effects of atomic oxygen on materials based on Batten [8]. Fig. 5 show the

inclusion of other gases compared with pure oxygen on Kapton weight loss was changed

to 6 - 60 % based on their result [8]. With a 95% of He and 95% Ar in 5% of 02, more

erosion of Kapton was observed while inclusion of the other gases has shown in

quenching. In order to fred effects of AO on materials, inclusion of other gases is not

appropriate and the purity of oxygen should be controlled.

The degree of dissociation of oxygen molecules to atoms in the RF discharge was

determined by using the mass spectrometer. For the calculation of the degree of

dissociation based on the measurement, the following assumptions have been made.

First, the effects dependent on two successive collisions can be neglected. Secondly, the

sensitivity of the filter section is identical for O ÷ ions assumed either from O or from

dissociative ionization of 02. Based on the assumptions made, the modulated signals Io

and Io2 at the peak of the O÷ and 02 ÷ were measured with the discharge on, and the ratio y

= no/no2 of the atom to molecular number of densities was calculated using the equation

from Miller [9]:

Y = k °'o ,1\ rl Io2

(4)

where P is 0.3, the probability of dissociative ionization of O2, o021o0 = 1.67 is the ratio of

ionization cross-sections for O2 and O [10]. The vl is defined as Io/Io2 is measured with

the mass peak ratios with no discharge.

8O
A second method of determining the degree of dissociation requires measurement

of the modulated signal Io2 at the 02 + mass peak. The modulated signal Io2 is measured

with the RF discharge on and a series of modulated signals measured atter the discharge

is switched off. The difference between these signals, then, represents the 02 molecules

which are dissociated by the discharge and degree of dissociation is given by

a = 1 102

, (5)

:o2

where, Io2" is the extrapolation of these signals to the time at which the discharge off

under the same conditions.

This method gives a degree of dissociation under several different running

conditions in agreement with the method of equation (4). The degree of the dissociation

was measured as function of power and flow-rate is shown in Fig. 6. The degree of

dissociation was found to be as higher as 66 % under the lower pressure condition (- 11

mtorr at 0.16 SCCM of flow-rate) in the figure. As the flow-rate increased the degree of

dissociation decreased to 5 percentage. As each of the curves shows the extent of

dissociation first increases as the flow-rate increases at the lower flow-rates and then

levels off. This effects is more pronounced at lower flow-rate where the power density

per molecule is higher. Over the higher flow-rate the yield was found to be relatively

insensitive to the RF power due to the lower power density per molecule.

However, the atomic oxygen flux density is increased as the flow-rate increased

as shown in Fig. 7. In the figure, the previous AO flux was measured as 2.7 x 1015

AO/cm:/sec. As the flow-rate increases the AO flux density in increased at 50W RF

power. At 1.0 SCCM of flow-rate, the AO flux density is obtained as 5.01 x 10 _6

AO/cm2/sec. To verify the flux density a Kapton weight loss was measured with 0.70

SCCM of flow-rate at the 50W RF power. Based on the experiment, the AO flux density

is measured as 2.67 x 1016 AO/cm2/sec shown as a white circle in the figure.

Mechanism of dissociation of molecular oxygen

A question may arise what potential state of atomic oxygen generated at the near

surface of space vehicle in LEO. The previous Table 1 does not show atomic oxygen

with a certain energy level for the consideration of their reaction with space materials. In

the range of 1 -10 eV that most space vehicles experience, vibrational and electronic

excitation. This needs to be considered for reaction with materials.

81
In Fig. 8, there are five potential energy curves given for the oxygen molecule

[10]. When dissociation of the molecule takes place from any of the four lowest

electronic states by collision of electron it leads to two oxygen atoms in a 3p state where

both atoms would be released in their ground states. If dissociation is produced in the

B3Eu" excited state, then one 3p state oxygen atom is produced and one in the excited 1D

state expressed in equation 4. The ground state of the oxygen atom is a 3p. The fast

excited state is 1D lying at 1.97 eV above the ground state, while the second and third

excited states lie 4.19 and 9.10 eV above the ground state. Therefore, the possible

dissociation of molecular oxygen can occur by one of two processes involving excitation

from the ground state to either the A3Eu ÷ or the B3Eu" excited state by electron collision.

02+e__O2,(A3_u+).___(_3p)+(_3p)+e (6)

This reaction can be measured by emission spectra between 200 and 900 rim.

Further Suggestions for a Upgrading Device

Atoms at thermal velocities have energies of a few tenths of an electron voh. In

this application, however, the required atomic oxygen energy in the range from about I to

10 eV. Typical intensities of various continuous=flow molecular beam sources function

of possible energy are shown in Fig. 9. For high energy AO system, an atomic oxygen

generator using an Hollow Cathode discharge or a Corona discharge to produce

metastable atoms of thermal energy may be suitable to generate up to I 0 eV as shown in

the figure. A higher energy of AO generator in combination of a RF and a Hollow

cathode discharges will provide the energy level in the range of I 0 eV. Ailer generated

AO through the RF discharge, the AO will be accelerated due to applied electrical

potential (- I kV) from two electrodes. Through the acceleration process most of atomic

oxygen ion and electron will also be generated. AIier the Hollow cathode discharge a

ground filter will help a recombination of ions and electrons to make neutral atomic

oxygen. The operational condition of the Hollow cathode system will be approximately I

kV with a few milli-ampere ranges.

For the further upgrade of the AO system, an OMA (Optical Multi-channel

Analyzer) system is needed to study the ionization pattern and molecular physics for a

detail study in erosion mechanism of materials.

Further recommendations for the AO system may include the followings:

82
1. Axial offset of the AO generator is needed to prevent line of sight ultraviolet

irradiation of the sample. A proposed schematic for the recommendation is shown in

Fig. 11.

2. Based on observation and the results from Batten's paper, the purity of oxygen is a

critical factor to get qualitative data. Therefore, the purity level of oxygen should be

held to research grade as 99.999% or above.

3. The Dwell time of the mass spectrometer is an important factor to get a correct data. It

is recommended that dwell time be set to 500 msec.

IV. Conclusions

The previous AO flux was measured as 2.7 x 1015 AO/cm2/sec from the mass

spectrometer. As the flow-rate increases the AO flux density in increased at 50W RF

power. At 1.0 SCCM of flow-rate, the AO flux density is obtained as 5.01 x 1016

AO/cm2/sec which is 19 times greater than the previous set-up. To verify the flux density

a Kapton weight loss was measured with 0.70 SCCM of flow-rate at the 50W RF power.

Based on the experiment, the AO flux density is measured as 2.67 x 1016

AO/cm2/sec that is fitted with the result from the mass spectrometer within 5 %. The

degree of the dissociation was measured as function of power and flow-rate. Result

shows the extent of dissociation fLrst increases as the flow-rate increases at the lower

flow-rates and then levels off. This effects is more pronounced at lower flow-rate where

the power density per molecule is higher. Over the higher flow-rate the yield was found

to be relatively insensitive to the RF power due to the lower power density per molecule.

83
References

[1] Daniel R. Peplinski, Graham S. Arnold, and Eugene N. Borson, "Simulation of Upper

Atmosphere Oxygen Satellite Exposure to Atomic Oxygen in Low Earth Orbit," NASA

Conference Publication 2340, 1984.

[2] G. S. Arnold, R. R. Herin, and D. R. Peplinski, "Atmospheric Effects in Low Earth

Orbit and the DMSP ESA Offset Anomaly," Air Force Report SD-TR-82-31, 1982.

[3] P. A. Gory and R. Grice, "Microwave Discharge source for the Production of

Supersonic Atom and Free Radical Beams," J. Phys. E: Sci. Instmm., Vol. 12, 1979.

[4] W. C. Neely, T. C. Yang, J. P. Wey, E. J. clothiaux, and S. D. Worley, "Production of

Ground State Atomic Oxygen in a Multifaetor Stress Environment,"

http://hvoerovtie.spLauhum.edu/neely/g_undao.htm, 1997.

[5] D. R. Miller and D. F. Patch, "Design and Analysis of a High-intensity Fast Oxygen

Atom source," Rev. Sci. Instrum, Vol. 40, 1566-1569, 1969.

[6] P. A. Gorry, C. V. Nowikow and R. Grice, "Recative Scattering of a Neon seeded

Oxygen Atom Beam," Chem. Phys. Lea., Vol. 55, No. 1, 1978.

[7] P. A. Gorry, C. V. Nowikow and R. Grice, "Reactive Scattering of a Helium-seeded

Oxygen Atom Beam," Chem. Phys. Lett., Vol. 49, pp 116-120, 1977.

[8] Carmen E. Batten, Kenneth G. Brown, and Beverly W. Lewis, "A Spectral Study of a

Radio-frequency Plasma-Generated Flux of Atomic Oxygen," NASA Technical Mem

4612, 1994

[9] D. R. Miller and D. F. Patch, "Design and Analysis of a High-intensity Fast Oxygen

Atom source," Rev. Sci. Instrum, Vol. 40, 1566-1569, 1969.

[10] Rapp D., Englander-Golden P and Briglia D., "Cross-sections for dissociative

ionization of molecules by electron impact," J. Chem. Phys., vol. 42, pp3240-50, 1965.

[ 10] John W. Bond, Jr., Kenneth M. Watson, and Jasper A. welch, Jr., "Atomic Theory of

Gas Dynamics," Addison-Wesley, p 144, 1965.

[11] John R. Hollahan and Alexis T. Bell, "Techniques and Applications of Plasma

Chemistry," p30, John Wiley & Sons, 1974

[12] H. G. Kuhn, "Atomic Spectra," Academic Press, New York and London, p391,

1969.

[13] Giacinto Scoles, "Atomic and Molecular Beam Methods," Vol. 1, p142, 1988.

[14] Robert F. Bacher and Samuel Goudsmit, "Atomic Energy States," Greenwood Press,

p333-348, 1968.

84
Impinging Velocity:

Atomic Oxygen Density:

Pressure:

Atom Oxygen Flux:

Ambient Temperature:

8 km/sec

"_ 10 9/cm 3

-_ 10 -7 torr

"-_ 1015/cm 2 sec

-_1000-1500 K

Required Energy:

8 km/sec (= 510 kd/mole, 5.3 eV, 8.5x 1012erg

122 kcal/mol)

Equivalent temperature ---6.15 x 104 K

Table 1. Physical Parameters at 300 km altitude

1. Energy:

2. Atomic Oxygen Flux:

3. Atomic Oxygen density

4. Power Density:

5. Power/molecule:

6. Pressure:

0.04 eV (far short for 5 eV)

3 x 1015/cm 2 sec

: - 1015/cm 3

0.11 W/cm 3

1.1 x 10 "16 W/molecule

20 - 80 mtorr

At 20 mtorr, average spacing betweenlatoms: _ 0.1 ktm

mean free path: 1.64 mm

frequency of collision per molecules: 0.3 MHz

Table 2. Status of the previous AO system

85
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93
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94
INVESTIGATION OF THERMAL BLEACHING IN

MANGANESE DOPED ORTHOALUMINATE SINGLE

CRYSTALS

George Loutts

Mikhail A. Noginov

Rosalind Wynne

Kai T. Ross

and

Talia Grandy

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, Virginia 23504

Telephone: 757-683-2031

e-mail: g_loutts@vger.nsu.edu

95

Investigation of Thermal Bleaching in Manganese Doped Orthoaluminate Single

Crystals

George B. Loutts, Mikhail A. Noginov, Rosalind Wyrme, Kai T. Ross and Talia Grandy

Center for Materials Research

Norfolk State University

Norfolk, Virginia

Key Words

Materials for Optical Storage, Thermal Bleaching, Optical Absorption

Prerequisite Knowledge

It is useful to have basic knowledge of physics, chemistry, and spectroscopy.

Objectives

To study the kinetics of thermal bleaching in manganese doped orthoaluminate crystals at

different temperatures using a custom-built temperature attachment to a Cary 5

spectrophotometer.

Equipment and Materials

• Mn-doped samples of YAIO3, YbA10 3 and GdA10 3 crystals, 4-10 mm thick

• Brass tube, around 3/8" I.D.

• Ceramic tube, 1" I.D.

• Heating tape

• Thermocouple, type K

• Temperature controller

• Cary 5 UV/Vis/IR spectrophotometer from Varian with Cary WinUV software (or

any other visible spectrophotometer with the software for kinetics measurements)

• Microcal Origin or Microsoft Excell software

Introduction

Single crystalline manganese-doped yttrium orthoaluminate (Mn:YAIO3) is a

promising material for holographic recording and optical storage [1,2]. A broad-band

coloration accompanied with a strong change in index of refraction can be photoinduced

in the crystals with a laser light of 550 nm wavelength or shorter wavelength. The

coloration is associated with the photoionization of Mn 4÷ ions to Mn 5+ions residing in the

97
aluminum octahcdral sites. The coloration and optical data recorded in the material are

stable for more than one year at room temperature. However, they can be erased within

minutes at a temperature above 250°C due to the reverse reaction Mn 5÷+ e -) Mn 4÷. The

goal of this experiment is to study the kinetics of coloration bleaching at different

temperatures and to compare thermal bleaching in Mn-doped orthoaluminates of yttrium,

ytterbium and gadolinium (Mn:YA103, Mn:YbAIO3 and Mn:GdA103). A custom-built

temperature attachment to Cary 5G spectrophotometer has been developed for the

experiment. The attachment allows measuring optical absorption of samples in the

temperature range from room temperature to 800°C.

Mn-doped Crystal Samples

Orthoaluminates of yttrium, ytterbium and gadolinium have a distorted perovskite

structure that belongs to the orthorhombic system, space group Pbnm [3]. Manganese

enters the structure in the form of Mn 2+ ions substituting y3. ions in the dodecahedral

lattice sites [4] and Mn 4÷ ions substituting A13÷ ions in the octahedral lattice sites [5].

Manganese-doped single crystals of YA103, YbAIO3, and GdA103 were grown by

the Czochralski technique in iridium crucibles under nitrogen atmosphere with 0.2% of

oxygen. The charges were prepared with A1203 and Y203 of 99.999% purity; Yb203, and

Gd2Oaof 99.99% purity. Manganese was introduced in the charge as MnO2 of 99.9%

purity in the concentration of 0.5 at.% with respect to AI. The YA103 crystals were

grown on a seed, oriented along the "b" direction of the orthorhombic unit cell. Other

orthoaluminates were nucleated on iridium wires. They became single crystalline after

several millimeters of pulling and the final orientation of their boules was close to the

crystallographic "c" axis. During growth, the pull rate was maintained at 1.5 mm/h and

the rotation rate at 15 rpm.

Experimental samples were cut from the boules in the form of tetragonal prisms

with faces parallel to the crystallographic planes "a", "b", and "c" and lengths of 4-10

ram. Square faces of the prisms were "window" polished and their comers were rounded

to fit a 3/8 inch diameter tube.

Experimental setup

Prior the experiments, samples were photocolored with a 1W argon laser beam for

several minutes. During the exposure the color changed from yellow-amber to dark

bluish-gray.

Optical absorption spectra of the samples were taken using the ultraviolet-visibleinfrared spectrophotometer Cary 5G from Varian. In order to measure absorption at

elevated temperatures, a small furnace that fits the sample compartment of the

spectrophotometer has been designed. A sketch of the furnace is shown in Figure 1. It

consists of a brass tube with 3/8 inch inside diameter and about 3 inch long. The tube is

wrapped with a heating tape and inserted in a porous alumina tube, 1 inch I.D., which

98
servesasheatinsulation. A K-typethermocoupleis insertedin apocketin thebrasstube

and connectedto a temperaturecontroller. (We used a Dimensioncontroller from

Research,Inc). The outputfrom thecontrolleris connectedto apowersupply,which is

hookedto the heatingtape. The Dimensioncontroller and the spectrophotometerare

interfacedto a PC so that both temperaturereadingand opticalabsorptiondatacanbe

downloadedandprocessed.

Optical absorption measurements

Optical absorption of photocolored samples was measured in order to determine

the wavelength of maximum in the absorption spectrum and then to record thermal

bleaching curves at that wavelength. Absorption spectra of the three materials are shown

in Figure 1. The maxima are located at about 650 nm in all the three materials. This

wavelength has been selected for recording of thermal bleaching curves and decay

kinetics curves at different temperatures

Thermal bleaching curves

In order to record thermal bleaching, each photocolored sample was placed in the

built furnace. The furnace was mounted inside the spectrophotometer so that the primary

light beam passed through the sample and reached the detector. The temperature

controller was programmed to raise the temperature from 25°C to 400°C linearly over one

hour. During this time, both absorption at 650 nm wavelength and temperature was

recorded simultaneously. The resulting graph is shown in Figure 3. It indicates a sharp

drop in optical absorption at temperatures specific for each manganese-doped material.

This implies that optical data recorded in the samples can be erased by heating them to

about 250°C in case of Mn:GdAIO3, 300°C in case of Mn:YA103 and 350°C in case of

Mn:YbAIO 3.

Kinetics of discoloration

Kinetics of discoloration in Mn:YAIO3, shown in Figure 4, was recorded

similarly. The temperature was quickly raised to a specific value and then maintained

constant for the rest of the experiment. It is clear that the discoloration rate strongly

depends on the temperature. In order to estimate the storage time at room temperature,

normalized absorption in Mn:YA103 was plot against logarithm of time, Figure 5. After

the initial period of 150 minutes, the experimental data can be approximated with a

straight line. The total duration of experiment was 4000 minutes. Assuming the kinetics

continues to further follow the straight line, one can estimate that the recorded pattern

will lose 50% of its initial intensity after around 120 years. This implies that Mn:YA103

is a promising material for permanent holographic recording.

99
Acknowledgments

The work was supported in part by the AFOSR/BMDO grant #F49620-98-1-0101

and DOE grant #DE-FG01-94EW11493.

References

, G.B. Loutts, M. Warren, L. Taylor, R.R. Rakhimov, H.R. Ries, G. Miller Ill, M.A.

Noginov, M. Curley, N. Noginova, N. Kukhtarev, H.J. Caulfield, and P.

Venkateswarlu. Manganese doped yttrium orthoaluminate: a potential material for

holographic recording and data storage. Physical Review B, 57, 1998, 3706-3709.

. M.A. Noginov, N. Noginova, M. Curley, N. Kukhtarev, H.J. Caulfield, P.

Venkateswarlu, G.B. Loutts. Optical characterization of Mn:YA103, material for

holographic recording and data storage. J. Optical Society of America B, 15, 1998,

1463-1468.

3. P.D. Demier and R.G. Maines, "High pressure synthesis and crystal data of the rare

earth orthoaluminates", Mat. Res. Bull., 6, pp. 433-440, 1971.

4. M.A. Noginov, G.B. Loutts, Spectroscopic studies of Mn 4+ions in yttrium

orthoaluminate, Submitted to Journal of Optical Society of America B, 1998.

5. M.A. Noginov, G.B. Loutts, M. Warren, Spectroscopic studies of Mrl 3+ and Mn 2+ ions

in YA103, Submitted to Journal of Optical Society of America B, 1998.

T,

100
Output Input

Figure 1. Schematic diagram of the temperature attachment.

101
3

2.5

1.5

0.5

0

4OO

3

'B 2

<

0

3,5O

l i i l

500 600 700 800 900

Wavelength, nm

,

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400 450 500 550 600 650 700 750 800

Wavelength,nrn

Figure 2.

10

9

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4

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3

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1

i | i i

400 600 650 700 750 800

(c)

i ! i !

450 5O0 550

Wavelenglh, n

Room temperature absorption spectra of non-exposed (trace 1) and exposed

(trace 2) samples of Mn:YAI03 (a), Mn:YbAI03 (b), and Mn:GdAIO3 (c).

102
0.8 0.9

0.7

0.6

_" 0.5

.8

co 0.4

_ 0.3

_ 0.2

0.1

z 0

100 200 300

Temperature, C

400

Figure 3.

Figure 4.

Figure 5.

Thermal bleaching curves of Mn:YAlO3 (1), Mn:GdAIO3 (2), and Mn:YbAIO3 (3)

recorded at 620 nm.

d 1Ix.

= i_-- 25 C

-'0.8

® 120C

t0.6

¢..

.2 0.4 J_ _ 200 C

_0.2

o 240 C

.Qo0 , ,

< 0 \ 1000 2000 3000

1260, 280 Cl Time, rain

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Kinetics of discoloration in Mn:YAIO3 at different temperatures.

1

0.95

0.9

0.85

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0

150 min

.

!

I

I

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I

2 4

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%

6 8 10

Abs/Abs(0)=0.5 at I--122 years

Kinetics of discoloration in Mn:YAIO3 at room temperature approximated with a

straight line.

103

THE MATERIALS SCIENCE

OF SUPERCONDUCTING MAGNETS

David Welch

Head - Materials Science Division

Department of Applied Science

Brookhaven National Laboratory

P. O. Box 5000

Upton, New York 11973-5000

Telephone: 516-344-3517

e-mail welch@sun2.bnl.gov

105
I

David Welch

106
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107
"Once molecules have learnt to compete and to

create other molecules in their own image,

elephants, and things resembling elephants, will

in due course be found roaming through the

countryside."

Ref. 1 Peter Atkins

The Creation

W. H. Freeman & Co. (1981)

108
Z

©

109
SURPRISE !

GiHes Hoist and Heike KamerHngh Ones

discover that in some metals electrical

resistance vanishes at a definite temperature

(not zero), i.e., "superconductivity". (1911)

°.

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HENDRIK CASIMIR

HAPHAZARD

REALITY

Half a Century of Science

_ HARPER COLOPHON BOOKS

Harper & Row, Publishers

New York, Cambridge, Philadelphia, San Francisco,

London, Mexico City, Sao Paulo, Sydney

Reprinted with permission of David Welch and Hendrik Casimir

112
113

rott t_$o
114
October 26, 1998

SUPERCONDUCTOR WEEK 3

RHIC Magnet Production

Completed

Brook,haven National Lab (BNL) announced the

end of magnet production for the RelativisitiC Heavv

Ion Collider (RHIC). A totalof 1,805magnets.--'"

including 65 spares have been either manufactured

at, or delivered to, BNL at a total cost of $165

million. The Brookhaven Bulletin reported that

magnet production required 929,500 tech-hours:

727,500 at BNL, 170,000 at Northrop Grumman, and

32,000 at Everson Electric Company. The magnets

contain 21 million meters ofsupe.rconducting wires.

BNL expects to complete mechanical assembly of

the RHIC ring by the end of the year and begin

subsystem testing in/anuary. Injection of the gold

beam will occur in March and detector installation is

slated for April and May. RHIC's first run is

scheduled for June or July of 1999. O

115
Why Did It Take So Long For

"Elephants" to Appear?

Because Materials Science and

Engineering can take a very long time!

What Happened?

"The early workers in superconductivity soon

discovered that there is an upper limit to the amount

of current that can be passed along a piece of

superconductor if it is to remain resistanceless. We

call this the critical current of that particular piece. If

the current exceeds this critical value, resistance

appears."

(A.C. Rose-Innes and E. H. Rhoderick, Introduction to

Superconductivity)

Why

Made

Aren't

of

The RHIC Magnets

"High-Temperature"

Superconductors ?

Because the critical current densities are too low

without very sophisticated processing and because

Materials Science and Engineering can take

frustratingly long times!

116
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The Era of ,,High-Temperature"

Superconductivity was _herexl m by

J.G. Bednorz and K.A. Muller.

Z. Phys. B, October 1986 issue.

118
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OPERATIONAL DEFINITION OF

CRITICAL CURRENT DENSITY

119
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magnetic field (1")

The variation of critical current density with magnetic field for

different materials- 1 NbTi at 4 K; 2 Nb3Sn at 4 K; 3 Y1Ba2Cu307

sputtered thin film at 77 K (Sumitomo); 4 Y1Ba2Cu307 MOCVD

thin film at 77 K (Tohoku University); 5 Y1Ba2Cu307 neutron

irradiated single crystal, critical current deduced from

magnetisation at 77 K (AT&T Bell); 6 Typical values at 77 K for

non-aligned polycrystalline YIBa2Cu_O 7 bulk samples; 7

Y, Ba2Cu307 melt-textured wire at 77 K (AT&T Bell); 8

Y_Ba2Cu_O7 QMG processed sample at 77 K (Nippon Steel); 9

Bi2Sr2Ca,Cu2Oe., wire at 4 K (Vacuumschmelze)

121
There are Two Major Issues

in the Problem of the Critical

Current Density in

Superconductors:

The Pinning of Magnetic Flux

The Transmission of Supercurrent

Through the Grain Boundaries of

Polycrystalline Superconductors

122
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125
126
Why Did It Take So Long For

"Elephants" to Appear?

Because Materials Science and

Engineering can take a very long time!

What Happened?

"The early workers in superconductivity soon

discovered that there is an upper limit to the amount

of current that can be passed along a piece of

superconductor if it is to remain resistanceless. We

call this the critical current of that particular piece. If

the current exceeds this critical value, resistance

appears."

(A.C. Rose-Innes and E. H. Rhoderick, Introduction to

Superconductivity)

Why Aren't The RHIC Magnets

Made of "High-Temperature"

Superconductors ?

Because the critical current densities are too low

without very sophisticated processing and because

Materials Science and Engineering can take

frustratingly long times!

127
Researchers at several of the DOE National

Laboratories (e.g., Ames, Argonne,

Brookhaven, Los Alamos, Oak Ridge, et

al.), as well as DOE-funded researchers at

several universities (e.g., Wisconsin,

Houston, et al.) are making vital

contributions to understaading and

alleviating the problems of the

current density of superconducto_ both

"high-temperature" and conventional.

The following are some examples of such

research at Brookhaven (Qiang Li, Yimei

Zhu, et al.) and Argonne (Ken Gray, Dean

Miller, et al.) National Laboratories.

128
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130
The two most important HTS:

1) YBa2Cu307 (YBCO, 123)

2) Bi2Sr2CaCu208 and Bi2Sr2Cs2Cu3Olo (Bi-based)

The previous studies of grain-boundary in HTS were

primarily on iBCO iiiiii iiiiiiiiiiJiii. ii ii i iii i 

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A Precipitous reduction of the tra,_sport critical current (Us) in

bicrvstal thin film with high-ancjle (Z ID°) grain boundaries

131
"7 + r+l"o:..+ +,t,+,_,.'_

• +

_,_..:_..: g + + .i"+'+/++ ...>._

+. _ _ -_=- .... +-: .-+_,,+...I _+",+- _..<++----p:..._me" +.."

.,.,I,,_ ¢+.

132
tl

133
134
Touchdown bearing

Armature 30 -200V

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tank

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m

I

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Superconducting bearing

Superconductor part Permanent magnel parl

Principle drawing.

135
CONCLUSIONS..

The large-scale applications of

superconductivity, including

superconducting magnets, will make

important contributions to our society in the

fields of electric power systems,

transportation, medical imaging, scientific

research, etc.

The role of Materials Science and

Engineering in bringing the potential of

high-temperature superconductivity to

fi'uition is both vital and challenging!

136
THE COLORFUL CHARACTER

OF MATERIALS

Edward L. Widener

School of Technology

Mechanical Engineering Technology

Purdue University

1417 Knoy Hall, Room 145

West Lafayette, Indiana 47907-1417

Telephone: 765-494-7521

e-mail elwidener@tech.purdue.edu

137
Edward L. Widener

138
THE COLORFUL CHARACTER OF MATERIALS

NEW:Update 98

Edward L. Widener - Purdue University

KEY WORDS: Brightness, Chroma, Coating, Colorant, Colorimetry, Illumination, Intensity, Tarnish

PRE-KNOWLEDGE: Primary & secondary hues. Metals-ceramics-polymers. Electro-chemical

oxidation. Patina & tarnish. Painting & plating.

OBJECTIVES: To associate whiteness & purity. To appreciate the major influence of minor impurities.

To understand the 3-dimensions of color. To describe colors accurately. To facilitate color-matching.

EQUIPMENT: 1. Small samples of commercial metals and alloys (steel, stainless steel, cast iron,

aluminum, magnesium, titanium, copper, brass, bronze, tin, lead, pewter, solder, galvanized or chromed

sheeting).

2. Small samples of plastics foams, films, and sheets (polyethene milk bottle, polyesther pop bottle,

polystyrene cup or packing, polypropene yogurt-cup or bottle-cap).

3. Small samples of ceramics (chalk, porcelain, drinking glass).

4. Magnifier, 5x- 10x.

BACKGROUND:

Everyone appreciates colorful scenes, jewels, textiles, photographs, movies, television - even comic

strips. But a world of"pure materials" is essentially colorless. Do our Materials Labs reflect this cloudygrey image of our pet topic? Are you neglecting the basics of Colorizing and Colorimetry by electing to

focus on routine Structures and Properties?

The 3-dimensions of Color are: Chroma (hue), Intensity (strength), and Radiance (brightness). You can

model these as a cylindrical tower, with circular floor-plans. Each floor is a level of Brighrness, ranging

from dark-basement to bright-penthouse. The Chroma-vector, like a horizontal compass-needle, points

toward primary and secondary hues. Strength of hue is the vector's radius.

Visible light is radiant energy, reflected from a material and seen by an eye. Combined wave-lengths

make white-light; but crayons act like filters which absorb all but your desired color. Thus, mixing all

crayons will make black. Abnormal eyes may see shades of grey, rather than spectral-colors Closed eyes

or shutoff lights make black.

Why are pure materials typically grey, white, cloudy, or clear (in various shades) except the gold,

copper, and sulfur elements? What metals change color when heated? What colors persist, after

cooldown? How do "rainbows"form on oil-slicks or soap bubbles? When do cold metals tarnish and turn

into variegated hues?

Colorizing involves surface coating, painting, or plating; but liquid dyes and solid pigments may wholly

permeate a product. Colorimetry depends on illumination, viewing angle, surface roughness, and color-fast

standard samples. For side-by-side matching, the human eye is an excellent Color Comparator.

BLACK & WHITE:

Metals are usually dull-grey if rough, or bright-grey if polished. They reflect like silvered mirrors,

being dense & opaque. Try looking through lightweight aluminum foil, when covering a lamp or

flashlight. Most metals oxidize at room temperature and have a thin ceramic coating. Look for subtle

oxide-tints, then clean each sample and judge each shade of grey. Steel oxides will range from pale yellow

to light blue, iflieated from 220 C - 340 C (say 430 - 640 F). Of course, "black-iron" or" hot-worked

steel" was oxidized to Fe304 ( red-hot at 900 C). And "damp-rust" is blood-red Fe203. Thus we see

iron-ores ranging from black (magnetite, loadstone) to red (hematite, taconite).

Non-metals (ceramics and polymers) are typically less dense than metals. They tend to be Iranslucent

(white, milky, cloudy) or even transparent (clear). Diamond is a cubic-crystal of pure carbon, and quartzite

is an hexagonal-crystal of SiO2 (silica); but the amorphous quartz-glass, known as "flne crystalware" is no

crystal at all; so why isn't it "cloudy"?

Plastics film also may be cloudy (polyethene milk-jug) or clear (polyesther pop-bottle, polystyrene

drinking-glass); foams and blocks are white, with polyethene duller than polyesther. Several plastics have

natural color, e.g. polyurethane (light orange), Nomex* Polyaramid (tan), and Kapton* Polyimide (deep

139
amber). Cellolosics (newsprint) will turn yellow in direct sunshine, being "tanned" by ultra-violet rays.

And sulfate pulp (kraft) is found in semi-bleached (tan) or unbleached (brown) papers.

COLOR MODELING:

The scientific"tri-stimulus" model in 3-dimensions is a strange blob, bounded by the varying sensitivity

of a normal human eye to visible light. However, a simplistic "Color Tower" may illustrate the 3-D

aspects of color characterization. Start with a cylindrical mailing-tube, a paper-core, or a foot of plastic

pipe; white vinyl-chloride or clear plexiglas-acrylic is good. When upright, the top of the tower is a brightpenthouse; whose center is white, the tower base is the dark cellar, whose center is black. In-between

floors are shades of grey.

Each circular floor-plan is an horizontal compass, with N the Red-direction, ESE the Yellow, and WSW

the Blue hue. Such Chroma are "primary colors", forming an equi-lateral triangle. Secondary colors make

a smaller inscribed-triangle, with S the Green-direction, ENE the Orange, and WNW the Violet hue.

Mixing two primary dyes (or pigments) gives a duller secondary color, as if moving to a lower floor. If

blended dyes are 180-degrees apart, the result is much duller, even grey or black.

Thus, dull orange is called "brown". Weak solutions are called "pastel-hues"; so intensity (s_ength) is

related to redial distance from the center of a room. A true dye, having innate secondary hue (orange,

green, violet) may be brighter than a blend of primary dyes. A true black is "glossier" than a mixed-blend

of opposing hues. Technically then, "platinum-blonde, gold, silver, copper, maize, and midnight"are misnomers to a colorist.

Amazingly, the blend of dots in a comic-strip or newspaper ads produces many hues, viewed by naked

eye. However, when magnified 5-10 times, only the primary colors are usually seen. The dot-density

corresponds to color intensity. Evidently, the brain integrates dicrete dots to perceive another hue.

RAINBOWS:

Imdescent "spectra" are seen in oily-films (floating on water); on soap-bubbles (in sunshine); on walls

(from glass-prisms); on CD-ROMs (from grooves); in color-photos of steel (pearlite lamina); in mother-ofpearl (abalone shells); in tarnished silver (spoons, coins); and in welded steel (hot oxides). When metals

corrode, the ceramic coating will vary in thickness, depending on conditions. The hotter the steel, the

thicker the translucent oxide, and the greater the diffraction of light. Thus different colors reach your eye,

as with an oil-slick..

Similarly, as silver is exposed to sulfite (or sulfate) paper, the oxide-coating may vary in thickness and

make a color-spectrmn, at room temperature. Compare a plain-steel weld with a stainless-steel bead; see

the narrow-rainbow in less-conductive stainless-steel. To exceed the "light-blue" temperature (about 340

F) is to produce rainbows of the second-order (or third) ; so, the oxide-color is related to temperature in

only the "out-board" rainbow (farthest from the heat-source).

Observations of color have practical applications. We see a machine-tool with oxide-color, we suspect

thermal over-heating, excessive grinder-pressure, or lack of coolant. The blacksmith "draws" a coldchisel, by quenching and tempering to a light-blue oxide. Of course, contaminates may produce ugly

corrosion, instead of "pretty toning"; then foreign materials or health hazards shall be explored.

REFERENCES:

1. Widener, E.L., "NEWmismatic Metallurgy", NEW:Update97 Proceedings, Seattle,WA (Coin Colors).

n,,ll,,n_ D K "Steel & Its Heat Treatment - Vol.I", John Wiley, NY, 1948 (p.38, Drawing).

....... ' " "' . . . • _th I ,, x_tr lt_,_A

3. Parker, S.P., "McGraw-Hill Dictaonary of Sclentafic & Technical Terms - 3 ca. , l-_x, 1y_,,¢.

140
e,,

SKETCH:

--- Primary Hues = Red, Yellow, Blue I'_ _ j 7]Y

THE COLOR TOWER--

Secondary Hues = O_ange, Green, Violet [ _ [

Radius of Vector = Intensity 1 !

Elevation of Floor = Brightness

BIOGRAPHY:

E.L. Widener has taught mechanical technology (MET) at Purdue University (since 1978), concen_ating

on statics, hydraulics, materials labs, ecology, & technical writing. Member ofASME, ASEE, ASM, ISA,

TAPPI. Registered P.E. in New York & Indiana. ABET visitor m from 1983 - 1990. BSME from Purdue

U. & MSEM from U. Kansas. Taught evenings at IUPU-Indianapolis & Danville IL.

Development Engineer for Coria-collagen casings, with Teepak Div. of Continental Group in Danville

(1976-78). Process Leader for Baker-McHem-y-Welch in Indianapolis (1974-76). Project Leader for

Creped-wadding & Secondary-fibers with Kimberly-Clark Co. in Memphis TN (1968-74). Process

Engineer for Nomex-nylon with E.I.duPont Co. in Richmond VA (1963-68). Associate Engineer for

Electro-furnace alloys with Union Carbide Co. in Niagara Falls NY (1952-60). Fuel Engineer with

U.S.Steel in Gary IN (1951-52).

Ed was in Malaysia, from April 1995 - June 1996, teaching Metals Lab to future technology teachers.

141

LABORATORY MEASUREMENT OF J-INTEGRAL

Yulian Kin

Harvey Abramowitz

Toma Hentea

Jim Higley

and

Jason Richards

Department of Engineering

Purdue University Calumet

2200 169th Street

Hammond, Indiana 46323-2094

Telephone 219-989-2684

e-mail kin@nwi.calumet. 9urdue.edu

143
Yulian Kin

144
LABORATORY MEASUREMENT OF J-INTEGRAL

Yulian Kin

Harvey Abramowitz

Toma Hentea

Jim Higley

Jason Richards

Purdue University Calumet

Key Words: Fatigue, crack propagation, crack growth rate, stress intensity factor, and J-integral.

Prerequisite Knowledge: Knowledge of basic fracture mechanics concepts is helpful.

Objective: Observe crack propagation. Measure crack length and angular rotation of a cracked

plate. Develop the following plots: moment versus angular displacement, energy versus crack

length, J-integral versus crack extension. Determine critical J-integral value.

Equipment:

1. Fatigue machine with a control unit (MTS, for example).

2. Fixture system to provide loading of the specimen (flexure system in this experiment).

3. Specimens (0.5-inch polycarbonate).

4. Video camera.

5. Light sources.

6. Computer with a frame grabber.

7. Monitor, printer.

8. Software to observe crack image measurements ("Inspector" by Matrox in this experiment).

9. Video recorder.

10. 0.75-inch scotch tape for the specimen.

Introduction:

This experiment focused on the polycarborlate which is used as a structural component in the F-16

aircraft canopy. The canopy is often manufactured from a laminated composite material.

Components of the composite are acrylic plies, a polycarbonate ply, interlayers and coatings.

Design of the canopy allows unloading of the acrylic ply which is why the structural polycarbonate

ply of the composite was the primary concern during fatigue investigation. One of the failures

encountered frequently in the field is polycarbonate fracture. The nature of failures is not quite

clear, but some evidence implies that transparency life is limited by fatigue of the polycarbonate

ply [1]. Therefore, development of an inspection procedure which permits measurement of crack

length and prediction of the part failure life is an important task.

145
At the 12th Annual National Educators' Workshop, the authors presented a paper [2] which was

relatedto experimentaldeterminationof stressintensityfactorsand constantparametersin the

Paris formulation.That experimenthas been implemented in Machine Design and Material

Science coursesat Purdue UniversityCalumet. This paper describesan additionalfxacturc

mechanics experiment for the course: Measurement of the J-integral. The experiment was conductedon thesame MTS machineand on specimensofthesame material.

Specimen:

The testing coupons were cut fi'om 0.5-inch thick polycarbonate sheets. The sheets had been

extruded, pressed and polished in accordance with the military specifications. The specimen

configurationisshown inFigure I.

_- 1/2"

t

3/4" _A 60%

f

t

I

I I/2"

f

Figure I: Specimenconfiguration.

Experimental Set-up:

Flexure tests were conducted on an NITS machine using a four-point loading technique to provide

pure bending. The experimental set-up is shown in Figure 2.

The crack images were caught by an image grabber linked to the digital computer and video. An

independent duplicate monitor connected to the video permitted constant observation of the crack

development during command and calibration operations.

146
TESTING

M_e_CHINE

FRAME:

FOUR

BENDING

LOADING

SYSTEM

TESTING

MACHINE

FRAME

HYDRAULIC

ACTUATOR

CONTROL UNIT I

I

[_ CAMERA & I LIGHT SOURCES I

J

VIDEO

RECI]RDER

I DIGITAL _

COHPUTER

VIEV A

FOUR

BENDING

LOADING

SYSTEM

OR

Figure 2: Experimental Set-Up

147
Observations:

Crack initiation and growth of the loaded PC specimen were constantly observed on the monitor

screen. To verify that crack initiation had occurred, the camera periodically zoomed in on the

specimen. During crack growth, the crack images were captured and stored by an image grabber

after each 200-lb. force increment. During zooming and calibration, crack propagation was

observed on the duplicate monitor.

Results:

Data is given in Table I and Table 2.

Table 1: Applied Load and Measured Deflection Data.

LoadP, N Av_ageAngul_ Deflection, Rajahs Bending MomentM, N-mm

890 0.006886 7242

1335 0.011097 10864

1779 0.012919 14477

2224 0.014113 18098

2669 0.016808 21719

3114 0.018267 25340

3559 0.020936 28961

4003 0.023151 32574

4448 0.025756 36197

From beam theory, the bending moment for the given geometry was calculated:

M = (P/2) * (1/2) * (94.46 - 61.91) N-mm = (8.1375 * P) N-ram.

The loading diagram is given in Appendix A. Angular deflection was determined from the

displacement, which was measured from the image grabbed during the crack growth (see Appendix

B).

Table 2: J-integral values calculated from the experimental data.

Area und_ MomentBending Moment M, Displacement Curve Uncracked Ligament b, 'YV_ue,

N-ram N-mm mm J/mm_ C_ck Lengtha, nun

7242 18.5 19.05 0.306 .000

10864 64.8 19.024 1.072 .026

14477 93.2 18.996 1.546 .054

18098 114.4 18.982 1.898 .068

21719 170.3 18.997 2.824 .053

25340 205.1 19.000 3.400 .050

28961 277.1 18.984 4.600 .066

32574 344.9 18.943 5.734 .107

36197 434.1 18.907 7.232 .143

148
Values for the J-integral was calculated from the following equation:

where:

J = 20a*U)/03 * b) mJ/mm 2

h = 2 for bending [3].

U - area under moment - angular displacement curve, N-mm

B - specimen thickness, mm

b - uncmcked hgament, mm

The area under bending moment versus angular displacement curve was determined from:

U --- f (1,502,145 D- 2491) dD

The plots generated from the experimental data received are given in Figures 3, 4, and 5.

40

3O

/

-10

0 0.01 0.02 0.O3

Avg. Angular Deflection (tad)

11 actual points !

• linear approx.

Figure 3: Moment Versus Angular Displacement.

149
80

70

w

Q

eu 60

e-

_so

t-i

Q

c

tU40

O

i3O

20

J

,/

J •

0 0.05 0.1 0.15

crack length (ram)

0.2

Figure 4: Total Energy per umt Thickness Versus Crack Length.

E

E

o

.._

E

8

- -/?'_

'7

0 0.05 0.1 0.15 0.2

CRACK EXTENSION, mm

Figure 5: J-Integral Versus Crack Extension.

150
Note that the first four measurements (see Tables 1 and 2) were not included in plots Figures 4 and

5, because these measurements were made during crack initiation and considered suspicious.

Applications of J-integral for fracture control:

Application of J-integral intends to control elastic-plastic fracture [3]. Therefore, the critical

J-integral value, Jc, for thick material permits one to determine the critical stress intensity factor,

I_, taking into account elastic-plastic behavior of the material around the notch:

IQ ^2 = (Jc * E) / (1 - v^2),

where:

K_ = critical stress intensity factor for the mode 1 failure.

Jc = critical J-integral value for the mode 1 failure.

E = modulus of elasticity.

V = Poisson's ratio.

Now, using linear elastic calculations, we can determine the actual stress intensity factor, K, at

certain stages of crack propagation and compare K and K_ determined earlier. For security

purposes, it is also practical to calculate J at certain time intervals or after certain degrees of crack

extension. Comparing J and J_ we can make a prognosis about the remaining resource of the part.

References:

. H. Abramowitz, T. Hentea, Y. Kin, Y. Xu, "Fatigue Investigation of Polycarbonate Used

for Aircratt Canopies", Aging qf Materials and Methods for the Assessment qt"

LoCeffmes ol'Engineering Plant - Proceedings Of the 4th International Colloquium, Cape

Town, South Africa, April 21-25, 1997, Penny (ed.), Balkema, Rotterdam, Netherlands,

ISBN 9054108746, 1997, pp. 309-317

. Y. Kin, H. Abramowitz, T. Hentea, Y. Xu, "Life Estimate Based on Fatigue Crack

Propagation", 12th Annual National Educators' Workshop Proceedings, Boeing, Seattle,

WA, 1997.

.

Jolin M. Barsom, Stanley T. Roefe, Fracture and Fatigue Control in Structures. Prentice

Hall, Englewood Cliffs, New Jersey, 1987.

151
PI2 PI2

1'

!

Appendix A: Loading Diagram

i I

1

!

l

!

Appendix B: Angular Displacement Calculation

Angular Displacement = arctan (B/C)

152
USE OF A FOUR-POINT BEND APPARATUS TO

DETERMINE THE MODULUS OF ELASTICITY

Richard B. Griffin

L. Roy Cornwell

Carlos Yapura

Sivasubramaniam Krishnan

and

John Hallford

Department of Mechanical Engineering

Texas A&M

College Station, Texas 77843-3123

Telephone: 409-845-9779

e-mail rgriffin@mengr.tamu, edu

153
Richard B. Griffin

154
Use of a Four-Point Bend Apparatus to Determine the Modulus of Elasticity

Richard B. Griffin*, L. Roy Comwell*, Carlos Yapura +, Sivasubramaniam Krishnan ++,

and John Hallford**

ABSTRACT:

*Faculty, Mechanical Engineering, Texas A&M University

+Postdoctoral student, Aerospace Engineering, Texas A&M University

++Graduate student in Mechanical Engineering, Texas A&M University

**Staff, Mechanical Engineering, Texas A&M University

A four-point bend test has been developed for use in the classroom. The test is

used to integrate fundamental knowledge in three courses: materials science, continuum

mechanics, and electrical engineering. The students are given beams of approximately

lmm in thickness by 25ram wide by 150mm in length. The deflection is measured by

placing masses on top of the beam. A dial indicator, supported on the underside of the

beam, is used to measure the deflections. Since the dial indicator provides an upward

force from the underside of the beam, the experiment provides an opportunity for the

students' to apply the principle of superposition. The analysis for the deflection is not as

simple as for the three-point bend test; however, using the four-point bend test eliminates

concerns about bending moments. The coupling with electrical engineering results from

the installation of strain gauges on the beams. The students' can see how strain gauges

work and actually calibrate the gauges. The students may select from mild steel, 304

stainless steel, cartridge brass, and unidirectional graphite/epoxy beam materials. The

results for determining the modulus of elasticity using a least squares approach are within

3% of tabulated values.

KEYWORDS: Bending, Modulus of Elasticity, Material Science, Four-point Bending,

Continuum Mechanics, Laboratory Activity, Classroom Demonstration

PREREQUISTE KNOWLEDGE: Calculus, Mechanics, and Physics,

OBJECTIVES:

To measure the modulus of elasticity using a 4-point bend experiment.

To give students an opportunity to use equipment.

EQUIPMENT AND MATERIALS:

Table 1 lists the equipment required for the beam experiment and the estimated

cost.

155
Table 1. Equipment needed for the 4-point bend test.

Components Estimated cost

Bend Fixture, Stainless steel

Dial indicator, collet, and extension

Weights

Beams

Screws, bolts, and nuts

Vernier caliper

$5O

$53

$25

Used available materials

$5

Available in laboratory

$133 Estimated cost per setup

SAFETY PRECAUTIONS: Proper laboratory procedures.

INTRODUCTION

Texas A&M University is a member of the Foundation Coalition, a National

Science Foundation program for educational reform.l For the past five years, Texas

A&M has been one of seven schools in the Foundation Coalition. During that time, a

five-course sequence was developed for the sophomore year. 2'3 Table 2 identifies the

courses and topical areas, the semester taken, and the course number. The thrusts of the

Foundation Coalition are teaming and active learning, integration, application of

technology, and development of lifelong learning. 4 The courses are based on the use of

conservation principles in an effort to integrate subject areas. 5

Semester

Fall

Spring

Table 2. Arrangement of courses.

Engineering Area

Mechanics- Statics and Dynamics

Thermodynamics- plus some fluids

Materials

Course Numbers

ENGR 211

ENGR 212

ENGR 213

Continuum Mechanics ENGR 214

Electrical Circuits and Electronics ENGR 215

Currently, the majority of the departments take all of the courses. The courses are

taught in lecture sections of about 80 students. The classrooms are equipped with desks

where four students sit as a group with laptop computer(s) on the desks. The room is

equipped with an instructor' s computer, document camera, and VCR, all of which can be

shown through the overhead projection system.

While these developments were very helpful, one area the faculty were concerned

about was the hands-on aspect of engineering. The current generation of students has

limited (in general) experience with building things, repairing equipment, or in

performing experiments. In an effort to remedy this situation, faculty in several of the

above sophomore courses have been developing activities, which can be performed in the

classroom. The particular course the authors are involved with is a property of materials

course, ENGR 213. The instructors have developed several in-class experiments; these

include a tensile test, bend test, electrical component demonstration, and a thermal

conductivity experiment.

156
Last year,wepresentedathree-pointbendexperimentfor usein theclassroom.6

As theresultsindicated,theexperimentworkedwell andhasbeenused.Unfortunately,

thesetupwasnotasrobustaswehadinitially anticipated,andby the time 180students

got throughwith thetests,severalitemswere eitherbrokenor notworking. Subsequently,

in aneffort to upgradetheexperiment,wedecidedto developa four-pointbendtest

experiment.Theobjectiveof thispaperis to describethedevelopmentand

implementationof the4-pointbendtest.

Theredesignedexperimentalsetupis shownFigure 1.Thedrawingsfor thebend

testapparatusareincludedin theappendix.

Figure 1.Photographof thebendapparatus.

PROCEDURE

The students are asked to select two beam materials for testing. During fall 1998,

which was the first time the new setup was used, it was requested that one of the beams

be graphite epoxy. The other could be of their choice: i018 steel, 304 stainless steel, or

cartridge brass. The students measure the specimen's dimensions, and the distances on

the bend fixture.

The model for the beam with its nomenclature is shown in Figure 2. The forces on

the beam and the reactions are shown in Figure 3.

157
I

dial gauge

Figure 2. Schematic setup for the 4-point bend experiment.

R1 R2

i I b 1 i

Figure 3. Forces and reactions for the 4-point beam experiment.

There are several methods for analyzing the 4-point bending beam experiment.

The method of superposition is one method, and another is the double integration

technique. Using the method of superposition, the following expression was derived, and

the relationship for the measured deflection, 6, is given by the following expression.

(kL 3 + 48EI)

Equation 1

If we rearrange this equation, we can solve for the modulus of elasticity, and the equation

may be written as the following.

E= P(3aL2 -4a3) kL3

4816 481

Equation 2

158
Where, P is the force, k is the spring constant (dial indicator), I is the moment of inertia,

L=2a+b, a and b are defined in Figure 3, I is the moment of inertia.

Using the double integration method, the following expression can be arrived at

for determining the modulus of elasticity. This expression explicitly contains the force

E_

(F*C, +F *C,_)

I*_

Equation 3

Where, F= P/2 (P is the load applied to the beam.)

F' is force exerted by the dial gauge on the beam

C1 = -a(8a 2 + 12ab +3b2)/24 and C2 = (2a +b)3/48 are constants and for the

geometry used in this setup C/ = -0.00007503, and C2 = 0.00004671

/-moment of inertia = wt3/l 2, w- width, t- thickness of the beam

I = 4.719 x 10 12 m 4 (Graphite-Epoxy)

6- net displacement of the beam

of the spring from the dial gauge. The data obtained using the above expression are

shown in Tables 4 and 5. For the beam tested, a= 0.04004m, b= 0.0508m, and

L=0.1309m were the dimensions used.

Another way to look at this problem is to use the ASTM Standard Test Method, D

790-96a, Flexural Properties of Unreinforced and Reinforced Plastics and Electrical

Insulating Materials. Two relationships are included in the standard for a load span of Vz

and 1/3 of the support span. These relationships are:

Eb =0.17L 3 m E_=0.21L3 m

bd bd

Equation 4 for V2 the support span. Equation 5 for 1/3 the support span.

L is defined earlier, b and d are specimen dimensions, and m is the slope of the load

deflection curve.

These two equations do not consider any upward force associated with a dial

indicator. The correction is relatively small, less than 5%, and therefore one could choose

to ignore the correction. If one does, a question that could be asked of the students is how

ignoring the upward force would affect the modulus that was determined. Of course, the

measured modulus would appear to be higher or the material would appear to be stiffer

when the force associated with the spring is ignored.

Determination of the spring constant

159
Thedial indicator,shownin Figures1and2, placesa smallupwardforceonthe

beamfrom theundersideasshownin Figure3, labeledF'. In orderto measurethespring

constantof thedial indicator,theextensiononthedial indicatorwasremoved,small

masseswereplaceddirectlyontheshaft,andthecorrespondingdeflectionwasmeasured.

An exampleof thedeterminationof thespringconstantis shownin Table3.

Table3. Determinationof thespringconstantfor dial gaugeNo.1.

Load applied (N)

0.07*9.81

Deflection produced (m)

0.00762

Spring constant (N/m)

90.118

0.08*9.81 0.00965 81.309

0.09"9.81 0.01151 76.732

0.10* 9.81 0.01344 73.090

0.11"9.81 0.01557 69.305

Average value - 78.0947

Determination of the modulus of elasticity

The students set the beam on the support, add masses, and measure the

deflections. An example of the data obtained is shown in Tables 4 for cartridge brass, and

Table 5 for graphite-epoxy beams.

Table 4. Data obtained for 70/30

Beam Material

Brass 70/30

Load (N)

_r cartridge brass (C26000) beam.

0.9 * 9.81

Net Deflection of

Beam (m)

Young's Modulus

(GPa)

0.5 * 9.81 0.002794 104.0071

0.6 * 9.81 0.0032766 104.1457

0.7 * 9.81 0.0038273 102.4791

0.8 * 9.81 0.0042672 103.7359

0.0048006 102.8105

Table 5. Data obtained for unidirectional graphite epo_

Beam Material Load (N) Net Deflection of

Beam (m)

2.2 * 9.81

:y beam.

Young's Modulus

(GPa)

1.0 * 9.81 0.0003732 223.504

1.2 * 9.81 0.0005002 197.9

Graphite Epoxy 1.5 * 9.81 0.0006780 180.46

1.7 * 9.81 0.00082296 176.905

2.0 * 9.81 0.0009574 168.45

0.001059 166.986

The data are plotted in Figures 3 and 4, and as can be observed they are linear.

Certainly for the analysis that was done this is encouraging, and what is expected for an

elastic analysis. Using the measured slopes, the modulus of elasticity has been

determined. For cartridge brass, the average value was 103GPa which compares with

110GPa listed in the ASM Handbook. 7 Unfortunately, the measured value for graphite

160
epoxy can not be compared to handbook values because the volume fraction of fibers and

the type of graphite fibers in the epoxy are unknown. However, the number determined is

reasonable.

CONCLUSION

We have developed 4-point bend test apparatus that can be used in a classroom

setting. The test has been performed in a classroom containing more than 60 students.

Currently, there are six setups available, and we are planning to increase the number to

20. The experiment couples with a sophomore level continuum mechanics course that the

students may be taking concurrently. In the near future, several of the beams will be

instrumented with strain gauges. The intent of this is to integrate with the electrical

engineering course.

70130 Brass F = 1958.8x - 0.5631

R2 = 0.9991

lO

8

v

O

2

I r

!

0.001 0.006

r

r

i

I

0.0o2 0.003 0.004 0.005

Deflection (m)

Graphite Epoxy

25

F = 16998x + 3.2572

R2 = 0.9952

0

0 0.0002 0.0004 0.0006 0.0008 0.001 0.0012

Deflection (m)

a. b.

Figure 3a and 3b. Load deflection curves for brass and graphite-epoxy.

ACKNOWLEDGEMENTS

The authors would like to thank the Foundation Coalition and the NSF for their

support of this project. A special note of thanks goes to Prof. Norris Stubbs for his help

with the mechanics part of the project, and to the students in the classes who performed

the tests, s

BIOGRAPHICAL INFORMATION

Richard Griffin has been at Texas A&M in Mechanical Engineering since 1977. His

research area is aqueous corrosion and he has received a NACE Technical Achievement

161
Award in 1992. For the past four years, he has been a member of the Sophomore Team in

the development of core engineering science courses for the Foundation Coalition.

L. Roy. Cornwell has been at Texas A&M since 1971. He has taught in the area of

material science and manufacturing. His research interests are corrosion and deformation.

C. Yapura is a post-doctoral student from Aerospace Engineering. His interests are

mechanics.

S. Krishnan is a first semester graduate student who is planning on studying mechanics.

J. ttallford is a technician in the materials area in Mechanical Engineering.

_Malave, 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 Engineering Education, Oct. 95, St Paul, MN, vol. 1 pp. 228-

232.

3Griffin, R. B., Everett, L., and Lagoudas, D., "Development of a Sophomore Year Engineering Program

at Texas A&M University," FIE, Pittsburgh, PA, Nov. 1997.

4 Lagoudas, D., Griffin, R.B., Everett, L.J., Keating, P., and Parker, D., "The Implementation of a

Sophomore Engineering Integrated Curriculum," ASEE Regional Conference, San Antonio, Texas, March

1996.

Giover, C., "Conservation Principles and the Structure of Engineering," McGraw-Hill, New York, NY,

1996.

6 R. B. Griffin and L. R. Cornwell, "MeasurementOf the Modulus of Elasticity Using a Three-Point Bend

Test," Conference, Seattle, WA, Oct. 1997.

7 Metals Handbook, vol. 2, Properties and Selection: Nonferrous Alloys and Pure Metals, ASM, Metals

Park, OH, 1979.

8 College of Engineering Students in ENGR 213, Fall 1998.

162
Appendix

,,r

II,,l i

i

_IE_

TOLERENCES

.XXX . ÷/-.OOI

_X - +i-.OC_

+/- i/"l

/2I

I_"__ 001

Is'_I'r I OF" 3

,.r,

.

rEX;,S A&',,ivxNERS:'_" CE_F OF _EC",",NIC;,LE_C / 'X .... I ....... ;

r3i@-:_ N8 rl/2-2a

_';_l o o o d o o o o

I"0 LERENCE_

.}(X'X q _/- .001

.XX " ÷/- .00S

I'-, i--oo2 i"

,/S I [-',,_ 2 OF" 3

TEXAS _,:M UNP,/E.RSI'Pr0EPT. OF _ECH,_4MIC.ALENG.

, t r _--. i.... i

I

t

o._J i

TOU[E1E_CES

.XXX - */- .OOI

.XX - +/- .005

- +/- 1131

I'-_ I-" oo_ I"

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163

MICROCHEMISTRY AND THE NEW

SCANNING ELECTRON MICROSCOPES

Matthew J. Kasdan

31932 Violeta Lane

Coto de Casa, California 92679

and

Stephen K. Kennedy

RJ Lee Group, Inc.

350 Hochbereg Road

Monroeville, Pennsylvania 15146

Telephone: 724-325-1776

e-mail www.rjlg.com

165
Stephen K. Kennedy

166
Microchemistry and the New Scanning Electron Microscopes

Matthew J. Kasdan

31932 Violeta Lane

Coto de Casa, CA 92679

and

Stephen K. Kennedy, Ph.D., PG

RJ Lee Group, Inc.

350 Hochbereg Road

Monroeville, PA 15146

Introduction:

Images produced by the scanning electron microscope (SEM) are becoming familiar to students

of all ages. SEM images are presented in text books, but are also seen in print and TV

advertisements for products such as hair treatments, wood finishes and insecticides. It is less

well known that elemental chemistry is also obtained using the SEM, yet it the combination of

imaging and microchemistry techniques that has lead to the widespread use of the SEM in

research and industry. The same combination of capabilities make the SEM a potentially

valuable tool in science education. The advances in modem SEM design with graphical user

interfaces using the point and click method of input make the instrument available to students of

all ages. However, even assuming that the SEM is an effective tool, it still remains that it is an

expensive instrument that only one or two people can operate at a time. To get widespread use,

the instrument needs to be a distributed resource. To this end, educational components can be

constructed around computer based exercises or computer SEM simulator. The SEM generates

an image (including the chemistry) that can be transferred over an intranet within a school

building, through distance learning facilities at connected schools, and over the World Wide

Web. Further, there are prototype systems developed by which instruments can be actually

manipulated from remote locations. Using a mix of these strategies, the SEM will be a

distributed and cost-effective resource.

Keywords:

Volcanism, Plate Tectonics, Earth's Crust, Scanning Electron Microscope, Microchemistry

Prerequisite Knowledge:

The student

1. should be familiar with the concept of plate tectonics

2. should know the classification of igneous rocks, including Bowen's reaction series

Objective:

The objective of this exercise is to help the student "discover" that there is a relationship between

composition of volcanic materials and their plate tectonic setting, and to investigate the reason

for this relationship. The student will learn to:

167
1. collect compositionaldataon the scanningelectronmicroscope,or using a computer-based

SEMprogram

2. determineaveragecompositionsfor differenttypesof volcanicmaterials

3. relatethecompositionsto theirplatetectonicsetting

4. usetheinformationfrom Bowen'sreactionseriesto explainthecompositionaldifferences.

Equipment and Supplies:

1. Map showing distribution of volcanic and earthquake activity on the earth's surface.

2. A diagram showing Bowen's reaction series in relation to the classification of igneous rocks.

3. A diagram showing the plate boundaries in cross section.

4. Scanning electron microscope with compositional analysis (energy dispersive spectrometer)

capability.

5. Volcanic material from tectonic settings including continental margin, island arc, hot spot

and/or ocean ridge.

6. Or stored digital images of 4 and 5 with display software.

7. Computer spread sheet if desired.

Test Activity:

This activity is to connect two concepts (volcanic activity in different plate tectonic settings and

the classification of igneous rocks) to establish an hypothesis. This hypothesis is tested using

data generated by an SEM. Implications resulting from these observations are discussed.

The first step is to review volcanic material (lava and magma) and how a volcano forms. Then,

on a map showing the geographic distribution of volcanic activity, note that volcanic activity is

not distributed randomly over the surface of the earth, but that it occurs at preferred locations.

These locations mark plate boundaries which can be described as converging (colliding),

diverging (spreading), or transform (slipping).

The second step is to review the classification of igneous rocks. In this step, the diagram

showing the order of crystallization of the most common rock-forming silicate minerals

(Bowen's reaction series) is emphasized. The first minerals to form (i.e., those formed at the

highest temperature) are silicates that are rich in iron and magnesium. When these crystallize,

they form igneous rocks that are referred to as ultramafic (ma for magnesium and fe for iron).

Subsequent minerals to form are successively enriched in silicon and aluminum relative to

decreasing amounts of iron and magnesium. When these crystallize, they form igneous rocks that

are referred to as sialic.

Formation of Hypothesis One:

The students are asked to combine the information of the two concepts discussed above and to

form an hypothesis regarding the composition of volcanic materials in various plate tectonic

settings, starting from a diverging plate boundary (or hot spot). They are to predict in general

terms such as most iron magnesium rich to most silicon aluminum rich or ultramafic, mafic and

sialic. To assist them, the students will be given a diagram which is a cross section of the plate

boundaries showing the volcanic activity.

168
Thefigure of adivergingboundarycrosssectionshowsthat thevolcanicmaterialin this setting

is derivedfrom the asthenospherewhich is composedof ultramafic materialand is partially

molten. The conceptualeapis for the studentsto predict the orderin which silicate minerals

will melt in a solid rock uponheatingwhenthe studentshave learnedthe orderin which the

mineralscrystallizefrom a melt uponcooling. The studentsmay recognizethis by themselves,

or theinstructormaydirectthemto this approachthroughquestions.

Oncethe hypothesisregardingthe compositionof volcanic material derivedfrom a diverging

plate boundaryhasbeenformed,the processis repeatedfor an island arc and ocean-continent

converging margin setting. The island arc setting should follow directly from the logic

employedin the divergingplateboundary.Theocean-continentconvergingmarginis somewhat

morecomplicated. The conceptualeap in this settingis to realizethat sedimentderivedfrom

the oceanfloor andfrom the adjacentcontinentis subductedwith the oceaniccrust and partial

meltingof bothmaterialsoccurs.

Formation of HypothesisTwo:

The studentis askedto determinethe generalcompositionof oceanand continentalsediment.

We start again with Bowen's reactionseries. The studentsknow that the different silicate

minerals crystallizedat different temperatures. The problem is to relate the temperatureof

crystallizationto stability at thetemperatureconditionsat the earth'ssurfacewheresedimentis

formedfrom thedecayofrocks.

HypothesisTesting:

Thehypothesisfor thecompositionof volcanicmaterialfrom eachtectonicsettingwill be tested

either by analyzingsamplesin the SEM, or by using a computerprogram which displays the

SEMimageandcomposition.

Thematerialfrom divergentmarginsandhotspotsis lava. Severallocationsonthespecimenare

examinedfor compositionandtheresultsfor thatspecimenareaveraged.The EDSspectrumis

acquiredand all elementsareidentifiedandtheir peakslabeled. This is illustratedin Figure 1.

The relativeproportion of eachelementis estimatedasthe areaof the peak for eachelement.

Thegeneralcompositioncanberepresentedastheratio of two groupsof elements;magnesium

plus iron (mafic), and silicon plus aluminum (sialic). The averagecomposition of the four

elementsare determined(by hand or by using a spread sheet)and the ratio of iron plus

magnesiumto silicon plus aluminumis calculated. Thehigher thevalue of this ratio (closerto

1.0),themoremaficthecompositionandthelowerthevaluethemoresialic thecomposition.

Theprocedureis repeatedfor additionalsamplesof thedivergentmarginsettingandfor multiple

samplesof volcanicmaterialfrom theotherplatetectonicsettingsaswell. All dataarepresented

in tableform.

Results:

Results from the analysis of six samples from three tectonic settings are presented in Table I and

in Figure 2. These results indicate that the composition of the volcanic material becomes

increasingly sialic moving from hot spot to island arc to continental setting. A combination of

partial melting and contribution of oceanic and continental sediment results in increasing the

169
silicon and aluminum contentrelative to iron and magnesium.The studentwrites a report in

which thehypothesesarestated,andtheresultsaresummarizedandinterpreted.

Comments:

Extension of the concepts learned can form the basis of additional activities. The density of the

mafic and sialic materials can be measured. This density can be related to the nature of the

layered earth and the origin of ocean basins. First, it is because of density differences that the

sialic material "floats" on the mafic material resulting in the layering of the earth's crust.

Second, because the sialic material is derived through the processes accompanying subduction at

convergent plate boundaries it is a discontinuous layer of the earth's surface. This results in the

fact that there are two "preferred" elevations of the crust, one where approximately 45% of the

earth's surface elevation ranges between three and six kilometers below sea level, and

approximately 29% ranges from minus one to plus one kilometer relative to sea level. Because

the earth's surface is covered with water, it is this distribution of elevation that results in defining

continents of sialic crust and ocean basins of mafic crust.

170
Setting

Table I - Compositional Results

Location Si A1 Mg Fe Ratio

Hot Spot

Island Arc

Island Arc

Continental

Continental

Continental

Hawaii

Average

Mt Pinatubo

Average

Mt Pinatubo

Average

Mount

St Helens

Average

Mt. Jemez

Average

Mt. Jemez

Average

32.7 18.4 4.1 10.2

36.7 10.2 13.3 14.3

43.9 17.4 2.0 8.2

43.4 18.2 3.0 8.1

39.2 8.3 16.5 14.4

39.4 20.2 3.0 9.1

39.2 15.4 7.0 10.7

22.9 5.7 5.7 11.4

63.0 ii.i 0.0 3.7

49.2 23.7 0.0 0.0

52.6 21.1 0.0 0.0

0.324

46.9 15.4 1.4 3.8 0.084

47.4 10.5 0.0 1.8

55.7 9.8 0.0 1.6

48.4 15.6 0.0 0.0

26.7 20.0 3.3 3.3

32.0 12.0 8.0 4.0

41.4 20.7 3.5 6.9

41.4 20.7 3 .5 3.9

41.9 15.6 2.6 3.5

44.3 28.9 0.0 0.0

48.5 24.2 0.0 0.0

44.9 26.5 0.0 1.0

46.3 27.4 0.0 i.I

64.3 13.3 0.0 2.0

0.106

49.7 24.1 0.0 0.8 0.011

69.7 ii.i 0.0 0.0

83.9 0.0 1.0 0.0

68.0 12.4 0.0 0.0

69.7 ii.i 0.0 0.0

66.3 12.2 1.0 0.0

69.1 12.4 0.0 0.0

71.1 9.9 0.3 0.0 0.004

56.2 i0

67.0 10

60.2 19

64.6 i0

67.7 ii

71.9 12

.I 0

3 0

4 0

3 I0

5 0

5 0

3 1

0 2.3

0 0.0

0 0.0

4 1.0

0 1.0

0 1.0

64.6 12 7 0.9 0.011

171
Figure 1 - SEM image and EDS chemistry of Hawaiian lava.

Continental

Hot Spot

#0 • • # #

Island

Arc

0.000 0.050 0.100 0.150 0.200 0.250 0.300 0.350

Ratio

Figure 2 - Results showing increase in mafic composition from continental, to island arc.

to hot spot p'late tectonic setting.

172
DETERMINATION OF THE CURIE TEMPERATURE

IN FERRO AND FERRIMAGNETS

R. Valenzuela

and

E. Amano

Institute for Materials Research

National University of Mexico

P. O. Box 70-360

Mexico 04510

Telephone: 525-622-4653

e-mail monjaras@servidor.unam, mx

173
R. Valenzuela

174
Determination of the Curie Temperature in Ferro and Ferrimagnets

R. Valenzuela and E. Amano

Institute for Materials Research

National University of Mexico, Mexico

Abstract

A system to measure the magnetic permeability as a function of temperature in a wide

range of ferro and ferrimagnetic materias is presented. Since in most magnetic materials the

permeability changes from a maximum in the magnetically ordered phase to a small value

in the disordered paramagnetic phase, this system allows an accurate determination of the

Curie temperature. The system is formed by relatively simple an inexpensive modules.

Key Words :

Ferromagnets, Ferrimagnets, Magnetic Transitions,

Prerequisite Knowledge :

The student

1. should know that some materials possess significant magnetic moments and show a

spontaneous magnetic order,

2. should have a basic knowledge of magnetic structures such as magnetic domains and

magnetic domain walls,

3. should be familiar with simple electrical circuits such as transformers, amplifiers, X-Y

plotters, and rectifiers.

Objective :

The objective of this exercise is to provide a phenomenological experience that shows the

effects of magnetic order on macroscopic properties such as magnetic permeability, how

temperature affects it, and how the magnetic transition can provide information on the

chemical composition and homogeneity.

The student will learn to:

1. Make the proper connections between the several modules in order to have an electrical

circuit to measure permeability as a function of temperature,

2. Prepare primary and secondary coils on toroidal samples of ferri and ferromagnetic

materials,

3. Test magnetic materials to determine their Curie temperature,

4. Analyze the results to understand the correlation between the thermal behavior of the

magnetic permeability and the microstructure of the sample.

Equipment and Materials:

1. Signal generator in the 1-20 kHz frequency range (General Radio oscillator 1310-B);

Amplifier-Rectifier with gain up to 40 dB (Philips PM 5171); X-Y Plotter with highest

sensitivity about 1 mV/inch (HP 7035 B); bridge for measuring inductance (Philips RCL

meter PM 6303); chromel-alurlael thermocouple, with a length about 1 m; small Muffle

Furnace (Thermolyne type 1500) for temperatures up to 500°C; two standard 50 f2

resistors

2. Copper wire for coiling (about 4 meters/sample)

175
3. X-Yplotterpaper and pens

4. ferri and/or ferromagnetic samples, preferably with Curie temperature in the 50-300°C.

5. Support

6. Thermometer to measure room temperature and Vernier calliper to measure sample

dimensions

Basis of the MeasurementS:

Ferro and ferrimagnetic are materials with a high content of transition-metal atoms (or

ions), which leads to a non-zero magnetic moment. In addition, under certain circumstances

of concentration and nearest-neighbor distance and arrangement, there exists a strong

interaction, known as exchange, resulting in a spontaneous ordering of magnetic moments

or spins. This is a ferromagnetic material. The magnetic ordering, capable of producing

strong attraction and repulsion forces in a macroscopic scale, is perturbed by thermal

agitation, and eventually it is destroyed at a well defined temperature, the Curie point, Tc.

The determination of this transition temperature is therefore very important.

A ferromagnetic material at T < Tc has a spontaneous ordering of spins, but due to the fact

that producing magnetic flux outside the material requires energy, the material is instead

divided into magnetic domains with different orientations in such a way that the magnetic

flux closes within the sample. The domains are separated by domain walls, which are zones

where spins rotate from the magnetic direction of one domain toward the direction of the

neighboring domain. A simple case is a 180 ° wall, as the boundary between domains with

opposite magnetization directions.

The application of an external field tends to produce a rotation of spins toward the direction

of the field. An effective mechanism for these rotations when domain walls are present is

the movements of these walls in such a way that domains with magnetization direction

parallel to the applied field grow at the expense of domains with opposite orientation. This

mechanism is very efficient since it requires fields significantly lower that the field requires

to produce a collective rotation of all individual spins. This can be evaluated by means of

the magnetic permeability, It, which is defined as the ratio between the magnetic induction,

B, and the applied field, H: _t = B/H.

In most ferromagnetic materials, permeability increases with temperature because thermal

agitation makes easier to move domain walls as temperature increases. However, when the

material reaches its Curie point, the exchange interaction is overcome by agitation, domain

walls disappear and permeability decreases down to the value of a non-ordered material.

This phenomenon is the basis of the measurement.

Some iron oxides, where magnetic ions are separated by oxygen can have "superexchange"

interactions through the oxygen ions. Although these interactions usually lead to an

antiparallel order, in some complex crystal structures there can exist several sublattices that

produce a resulting magnetic moment; this is the case of "ferrites". These oxides behave in

a very similar way to ferromagnetic metals.

Test Activity Overview:

Circuit preparation:

The circuit layout appears in Fig. 1. The signal generator (SG) provides a small ac current

to the primary coil (Np); the magnetic field produced by this coil magnetizes the sample (S),

and the magnetic flux produced by it is sensed by the secondary coil (Ns), as a voltage Vs.

176
This voltage is proportional 2 to the inital magnetic permeability, gi, of the sample. Vs is

then amplified and rectified by the AR module. A dc voltage, Vr, proportional to the

amplitude of Vs (and therefore to g_), is provided to the X-Y plotter, in the Y-axis.

The primary coil has typically a very small resistance; to limit the current amplitude and

protect the signal generator from a virtual short-circuit operation, a 50 f) resistor should be

connected in series to the primary coil circuit.

Since the input impedance of the AR module is very high, the secondary coil voltage Vs is

better detected by connecting a 50 f) resistor in parallel and sensing this signal on the ends

of this resistor. This allows the AR module to operate as a voltage amplifier, which is its

normal operating mode.

Primary and secondary coils:

The use of toroidally shaped samples facilitates the measurements, since all the magnetic

flux is inside the sample and demagnetization fields are absent. The number of primary and

secondary coil turns depends on the size of the toroid, the magnetic softness and the initial

permeability value of the particular sample. For most soft ferrites, however, values of Np/N s

in the ranges (3-6)/(5-15) lead to a good signal-to-noise ratio.

SG A

Thermocouple

±

Plotter

Figure 1. Layout of the measuring circuit.

Testing

Procedure:

Sample Preparation:

The first step is to measure sample dimensions, outer diameter (OD), inner diameter (ID),

and height, h. A recommended procedure is to fabricate first the secondary coil, measure

the sample inductance, L, and calculate the permeability. Since the secondary coil has more

177
turns than the primary one, it is easier to fabricate it first. Also, a larger value of inductance

is obtained with more rams (the inductance value varies as N,2, therefore reducing reading

error. The relative (adimensional) permeability value is calculated as:

_t = 50 (L) / [hNs 2 In, (OD/IN)] (1)

where In, is the e-based logarithms and h should be expressed in meters and L in _tH

(microHenrys). This value of permeability is used to set the Y-axis for final results.

The next step is to fabricate the primary coil. It is recommended to mark the ends of both

coils with a bit of masking tape. These ends are connected and the sample is fixed to the

thermocouple.

Callibration of plotter Y-level:

A convenient voltage, Vv, should be applied to the Y-axis of the plotter to obtain a proper

p (7) curve on the paper. The Y-voltage in the plotter depends on the following factors:

permeability of the sample, p, its dimensions, current level, i, and frequency, f, in the

primary coil, Np, N,, gain in AR module and gain in the Y-axis itself. For a given sample,

we can play (within certain limits, of course) with i,f Np, N_, AR gain and Y-axis gain.

Increasing i leads to an increase in V_. An excesive current amplitude can overcome the

critical field which separates the initial permeability from hysteresis; under these

conditions, the secondary voltage (V,) is no longer a linear function of permeability.

Fortunately, for most ferrites, the critical field (also known as propagation field) is

relatively large, and a current amplitude of a few miliamps is safe enough to perform the

experiment.

25O0

20O0

1500

1000

5O0

0

0

i ......

I , I , I , I i I i I I

20 40 60 80 100 120

T (°C)

i40 160

Figure 2. Typical thermal behavior of the permeability of an homogeneous MnZn ferrite,

from Ret _.

178
TheY-axisresponseonthe plotter can then be adjusted by combining AR and plotter gains.

As a general practice, the Y-axis pen is initially positioned about the middle of the total

available displacement, since most magnetic materials exhibit an increase in p. with

temperature, Fig. 2.

Callibration of plotter X-level:

The thermocouple is connected to the X-axis of the plotter. The gain in the X-axis should

be adapted to the expected Curie temperature of the sample, in order to have the maximum

X displacement and therefore increases the measurement precision. In the plotter used, the

highest sensitivity is 1 mV/in with a length of 10 in, therefore allowing measurements up to

246°C. For higher transition temperatures, a callibration of the X-axis can be done to some

2.5 mV/in which allows measurements up to 600°C, encompassing virtually all the known

ferrites.

Testing

Once both X- and Y- plotter axis have been set, the sample is fixed to the thermocouple and

introduced into the muffle. A slow heating rate is set (lower than 8 °C /min). In most

magnetic materials, the initial permeability increases with temperature up to the transition

point. At this temperature, a drop is observed indicating the phase change from an ordered

magnetic structure (ferro or ferrimagnetic) toward a paramagnetic, disordered state, where

the permeability has a very small value.

300O I I I

2OOO

1000

0 i I i I i I , L

0 50 100 150 200

T(°C)

Figure 3. Example of an inhomogeneous NiZn ferrite, with a non-vertical drop at the Curie

point. It is also indicated a method to evaluate Tc and inhomogeneity as AT (P. GutirrrezAmador, unpublished results)

179
Oncethis drop hasocurred, the muffle is turned off, and the plotter pen is changed(a

different color for cooling). It is alwaysimportantto recordthe coolingprocess,sincethe

transitionis areversibleprocess.

In most cases,the permeability drop at the magneticphasetransition is not a perfect

vertical.Since Curiepoint dependsessentiallyof magneticinteractions,this implies that

there is some degreeof chemical inhomogeneityin the sample.To report the Curie

temperaturemeasurement,someconventionhasto beestablished.A simpleonewould be

to reportthe temperatureat the permeabilityhalf-height(in many casesthe permeability

valueis maximumjust beforethe drop),plus thetemperatureincreaseto reachthebaseline,

asshownin Fig. 3.

References

R. Valenzuela. Magnetic Ceramics. Cambridge University Press, 1994

2 E. Cedillo, J. Ocampo, V. Rivera and R. Valenzuela. An apparatus for the measurement of

the initial magnetic permeability as a function of temperature. J. Phys. E: Sci. Instr., Vol.

13, 1980, pp. 383-386

3 A. Pelfiiz-Barranco, M.P. Guti6rrez-Amador, A. Huanosta and R. Valenzuela. Phase

transitions in ferrimagnetic and ferroelectric ceramics by ac measurements. Appl. Phys.

Lett. Vol. 73, 1998, pp. 2039-41

180
Raul Valenzuela

Born April 28, 1946, at Mexico City, Mexico

Chemical Engineering from University of Mexico, 1969

Ceramic Engineering specialization from Ecole de Sevres, France, 1970

PhD on Materials Science from Universite de Paris VI, France, 1974

Full professor at Institute for Materials Research, National University of Mexico, Mexico

Head of the Metallic and Ceramic Materials Department

Author of the book Magnetic Ceramics, edited by Cambridge University Press, UK, 1994

Coauthor of some 80 research papers

Visiting professor (sabbatical) at the Department of Chemistry, University of Aberdeen,

UK, 1991-1992.

Visiting professor (sabbatical) at Institute for Applied Magnetism, Universidad

Complutense de Madrid, Spain, 1994-1995.

181

EDUCATIONAL AND PUBLIC OUTREACH FOR

THE MARS SAMPLE RETURN PROJECT

S. Raj Chaudhury

and

Gae Golembiewski

BEST Lab

Center for Materials Research

Norfolk State University

2401 Corprew Avenue

Norfolk, Virginia 23504

Telephone: 757-683-2381

e-mail schaudhury@vger.nsu.edu

ggolem@vger.nsu, edu

183
m

m

!

S. Raj Chaudhury

184
Educational and Public Outreach for the Mars Sample Return Project

S. Raj Chaudhury and Gae Golembiewski

BEST Lab

Norfolk State University

2401 Corprew Avenue

Norfolk VA 23504

schaudhury@vger, nsu. edu

ggolem@vger, nsu. edu

NASA Langley Research Center will be responsible for the design,

development, test, fabrication and integration of a Sample Return

Capsule (re-entry vehicle) that will bring back to Earth several

dozen samples of Martian soil and rocks. Within stringent cost and

mass restrictions, appropriate materials must be selected for both

the outer shell of the capsule itself as well as shock absorbent

material designed to protect the cargo canister (sample holder).

Working with NASA Langley personnel, the BEST Lab team at NSU is

embarking on an educational and public outreach effort to develop

parallel laboratory activities for students in design, technology,

engineering and physics. These will closely follow the actual

concept implementation by the Langley group, who will rely solely

on aerodynamics for deceleration and attitude control of the entry

vehicle. Not using a parachute requires packaging the samples in

a hardened container with sufficient energy-absorbing material to

assure containment during ground impact.

Preliminary directions for the educational aspects of this project

will be discussed.

S. Raj Chaudhury

Norfolk State University

Center for Materials Research

2401 Corprew Avenue

Norfolk VA 23504

Phone: (757) 683-2241

Fax : (757) 683-9054

schaudhury@vger, nsu. edu

raj@vigyan.nsu.edu

http://vigyan, nsu. edu/

185

GALVANOSTATIC POLARIZATION CURVES

FOR TEACHING PURPOSES

Carlos E. Umana

Department of Materials

School of Mechanical Engineering

University of Costa Rica

San Jose, Costa Rica

Telephone 506-235-6350

e-mail caruma@terraba.fing.ucr.ac.cr

187
Carlos E. Umana

188
GALVANOSTATIC POLARIZATION CURVES FOR TEACHING PURPOSES

Carlos E. Umafia

Departamento de Materiales

Escuela de Ingenieria Mecanica

Universidad de Costa Rica

San Jose, Costa Rica

KEY WORDS: Potentials and reference electrodes, current density, polarization, anodic and cathodic

reactions, corrosion rate.

PREREQUISITE KNOWLEDGE: An understanding of the fundamentals of corrosion phenomena. This

experiment can be done once the basic knowledge about polarization mechanisms has been taught.

OBJECTIVES:

1. To obtain polarization curves without having to use sophisticated equipment and without previous

experience.

2. To bring hands on knowledge of the details involved in a polarization test.

3. To encourage students to explore the details of corrosion theory.

EQUIPMENT AND SUPPLIES:

1. Saturated calomel electrode (S.C.E.) 12 mm diameter x 110 mm length

2. Filtered DC power source (P.S.), output 0 to 40 v

3. Two digital high impedance multimeters. DC range: 0-2 v; 0-200 BA and 0-2 mA

4. Three variable resistors 1M.Q (best known as potentiometers) and three graduated knobs for the variable

resistors

5. Nitrogen tank and regulator

6. Balance (max. mass to weight +12g), readability to 0.1 g

7. Hot plate

8. Stopwatch

9. Immersion thermometer _ 0 - 50 °C

10. pH meter (optional)

11. One 600 ml beaker and two 250 ml beakers

12. A 300 x 120 x 5 mm PMMA plastic plate to build the electrode's supporting system

13. Aluminum bar (5/16" diameter x _ 4") and angular shape (3/8" x 3/8" x _ 2" length)

14. Two nylon cable ties (0.1" wide)

15. One mild steel bolt (1/4" diameter x 4.5")

16. 240-400-600 grid SiC paper

17. Caliper

18. Graphite bars from disposed size D dry cell batteries

19. Teflon ® PTFE pipe thread sealer tape

20. 2 meters of polyethylene hose (1/8" inside diameter).

21. Two battery clips (10 amps size x 2" length) and three steel binder spring clips (3/4" wide)

22. Sodium Chloride (99 % pure or higher)

23. Distilled water (D.W.)

189
24. Piece of plastic spring binder to hold and control immersion depth of the S.C.E.

25. Glass tube of 1.5mm internal diameter x _,100 mm

26. Electric cables

INTRODUCTION:

Polarization curves have been used to study corrosion phenomena for many years (Ref. 1). They are a very

important tool for researchers and engineers and are treated in almost all materials science and engineering

texts available. However polarization curves involve some electrochemistry concepts which are difficult to

assimilate.

It goes without saying that the most effective and easiest way to understand polarization curves is by

measuring, plotting and analyzing them. These curves can be obtained by three experimental techniques

(Ref.2): a. potentiodynamic, b. potenciostatic, and c. galvanostatic. The first two techniques require

sophisticated equipment, usually not available in mechanical or materials engineering schools. The third

technique has some limitations, but due to its simplicity offers a good alternative.

This expefimem is based on the galvanostatic technique, which has been simplified in such a way that an

instructor or professor can use it without the limitations of sophisticated equipment. Most of the materials

and equipment required for the experiment are easily obtained.

After performing the experiment it is expected that students will have a better understanding of concepts such

as reference electrodes, corrosion potential, corrosion current densities, cathodic and anodic over potentials,

polarization, Tafel slopes, etc. It should be clear that even though the experiment described is only for

teaching and not for research or professional purposes the basic principles are the same in all cases.

THEORETICAL BASIC CONCEPTS:

A corrosion system always consists of anodic and cathodic areas electrically connected and immersed in a

common electrolyte. The most common form of corrosion in known as uniform or general overall corrosion

(Ref.2). The external surface of any isolated piece of metal or alloy that undergoes uniform corrosion is

always composed of multiple anodic and cathodic micro-areas as shown in Figure la. These micro-areas

continuously change location as corrosion goes ort All anodic areas and all cathodic areas of the metal

surface can be schematically represented as in Figure lb. and usually it is assumed that both areas are equal

(Ref.3). In this paper it is assumed that electron flow and current have the same direction.

If an external current is applied as occurs with a polarization test or an impressive current cathodic protection

application, the system may be represented by the configuration of Figure 2. For a negative power source lead

connection as shown in Figure 2, applied and internal currents converge at the cathodic area, which allows to

establish the following current relation:

Ic,tot= Ic.appt÷ lc,mt (1)

Where:

arc, tot = Total cathodic current

I¢,,_,pt= Applied cathodic current

lc,mt= Intemal cathodic current

190
Normallyrelation(1)isdividedbythetotalworkingelectrode(W.E.)areato givethefollowingcurrent

densityrelation:

Where:

lc, tot = ic, appl z_ lc, int

it.tot= Total cathodic current density

ic.,_,pl= Applied cathodic current density

Cmt = Internal cathodic current density

For the W.E. connected to the positive lead, applied and internal current leave the anodic area giving as a

result the following relations:

(2)

and

Where the suffix "a" stands for anodic.

reversed.

l to, = l ppt ÷ (3)

la't°t : la,apP1 -- la,int (4)

Also notice that Ic.in t and ic.mt changes to I,_mt and lkmt if the polarity is

Figure 3 shows a polarization diagram where Eco_ris the open circuit corrosion potential and i¢orr is the

corrosion current density and these parameters are supposed to be constant for each metal or alloy m a

specific electrolyte under controlled conditions. Overpotentials are measured using E¢o_ as reference potential,

and for any potential it is deduced that l_.mt=l,_. Relations (2) and (4) are graphically represented in Figure 3.

Figure 4 shows how a polarization diagram is obtained form experimental polarization curves. These curves

are plots of applied current density instead of total current density values, and for all cases i,,ppt< itoL. This

explains why experimental polarization curves deviate from a linear behavior for small overpotentials.

Therefore it stands to reason that experimental polarization curves and polarization diagrams are not the same

thing.

Average corrosion thickness loss rote is a function of the corrosion current density (i_o,_) that results from the

intersection of the cathodic extrapolation line with the E¢o_ line potential in a polarization diagram. This is

possible using a form of the Faraday's equation which is as follows:

th i. A.W.

t - F.n.p (5)

Where_

th = Thickness (cm)

t = Time (s)

i = Current density (A/cm 2)

A.W. = 1 mol of the element (g)

F = Faraday's constant: 96,500 (A-s)

n = Element valence

p = Density (g/cm 3)

191
Thecorrectinterpretationof theresultoftheequation5appliedto acylindricalsurfacemeansthattheW.E.

radiusisdecreasingattherategivenbythisequation.

As wasmentionedbeforetheanodicandcathodicmicro-areasat theW.E.changelocationascorrosiongoes

on. Forthatreasonthecorrosionwill affecttheentireW.E.surface.

Thetypeandnatureof theelectrolyteplaysaveryimportantrolein corrosionbehaviorandaccordingtothe

pHvalueandtheoxygencontentit ispossibleto havethefollowingbasicclassification:

ELECTROLYTE

ACID SOLUTION

- NEUTRALSOLUCION--

DEAERATED

Dueto highconductivity:Luggin

probe(Ref.10)notnecessary,high

densitycurrentsallowed

Cathodicactivationpolarization

AERATED

Possible complex cathodic

polarization reactions

DEAERATED

Applies Tafel slopes

NaC1 improves conductivity

Luggin probe not necessary

Cathodic activation polarization

Corrosion controlled by cathodic

concentration polarization.

PROCEDURE:

1. Build the PMMA electrode's supporting system according to Figure 5.

. Open some discharged size D dry cell batteries and extract the central graphite bar. Wash and brush the

graphite bars and immerse in distilled water for 24 hours. Choose the bars that do not show air bubbles

adhered to the surface to minimize porosity. For the operation wear gloves and avoid skin contact.

Dispose conveniently the residual material.

3. Cut, degrease, wet grind with 240-400 and wet polish with 600 grid SiC paper the mild steel bolt, give

emphasis on working area shown m Figure 6a. Rinse with distilled water and dry with an air blower.

4. Cover the working electrode and the graphite auxiliary electrode with PTFE Teflon ® pipe thread sealer

tape according to Figure 6.

5. Fill the 600 ml beaker with distilled water.

192
6. Putthebeakeronahotplate,allowto heatupandlet it boilfortwentyminutes.

7. Removethe beaker from the hot plate, cover it with a clean plastic bag and allow it to cool down to room

temperature. This will take around 12 hours. Handle the beaker with care, do not shake it.

. Add pure sodium chloride to make up a solution equivalent to 20g of NaCl per 1 liter of D.W. Do not use

mechanical stirring to dissolve the salt; instead bubble nitrogen to dissolve the salt to obtain an

homogeneous solution.

9. Fill a clean 250 ml beaker with 200 ml of the sample solution and save the rest of the solution. Pour the

sample solution into the beaker slowly without air bubbling.

10. Set up the circuitry shown in Figure 7. Use an empty 250 ml spare beaker to hold the supporting plastic

plate lid, install all the electrodes, except W.E., and connect them to the corresponding leads. Leave the

common input ammeter-resistor connection open and the voltmeter common input connected to the

S.C.E The experimental arrangement is presented in Figure 8.

11. Prepare the experimental data sheet of Table I and fill in the initial information, including the current

values.

12. Set the nitrogen flow in the 200 ml sample solution to about two bubbles per second and insert the glass

nitrogen pipe in the lid.

13. Make sure all the resistors are set to maximum resistance (0 reading on dials).

14. Degrease the W.E. and install it in the supporting plastic plate lid and connect to the ammeter and to the

voltmeter.

15. Turn on and set the voltmeter to a 2-volt range.

16. Place the plate lid on the sample solution beaker and measure the time from the moment of immersion.

17. Record the open circuit potential (E_o_ _ -520mv) after 90 minutes for the cathodic test run. For the

anodic test wait until the former E_o_ris reached.

18. Turn on and set the ammeter to the lowest current range, then turn on the power source (P.S.) and set it to

around 2 volts (to avoid the reverse current due to the natural potential difference between mild steel and

graphite).

19. Insert into the ammeter the terminal from the resistors that closes the circuit, record the initial time and

slowly increase the current by increasing the P.S. output voltage. From this moment it takes about 1 hour

to complete the experiment for one curve, the average current rate is 5gA every 10 seconds.

20. When 10 _xA is reached, wait 1 minute and then record the corresponding potential. Repeat this

procedure for the different currents established in the polarization data sheet, corresponding to table I.

193
21. WhenP.S.maximumvoltageisreached (mound 42 V) increase the current by using resistor number 1

until resistor number 1 reaches zero resistance.

22. Finally proceed as before but control the current by using alternatively resistors number 2 and number 3

until the maximum current is reached (the parallel connection makes it possible to control current at lower

resistance values).

23. Record the final time.

24. Close the nitrogen supply and turn offthe P.S., then turn offthe amp and volt meters.

25. Move the supporting plastic plate lid to the spare 250 ml beaker.

26. Dispose of the 200 ml solution, and fill again the 250 ml beaker with 200 ml of the original sample

solution.

27. Remove the Teflon* tape from the W.E. Wet grind with 240 grit SiC paper and wet polish with 600 grit

SiC paper. Again cover the W.E. with Teflon according to Figure 6a.

28. Reverse the P.S. (Anodic connection) and the ammeter connections (W.E. connected to common input

ammeter). Leave the ammeter-resistors connection open.

29. Repeat steps 12 through 24 then go to step 30.

30. Using the data of table I, plot the cathodic and anodic reaction curves on a 2-cycle semilogaritmic paper.

EXPERIMENTAL RESULTS:

Table I shows the values obtained in one polarization test and Figure 9 presents the cathodic and anodic

reaction curves (This figure was obtained using MATLAB* with Simulink V4.0, The MathWorks, Inc.).

The average corrosion potential is Eo_r = -522 mv and the cathodic and anodic curve extrapolation

corresponding to Tafel behavior gives a corrosion current density of i_,, = 32.3 lxA/cm 2. The cathodic Tafel

slope is [3c= -550 mv / decade (1 cycle = decade) and the anodic Tafel slope is 13a= 60 mv / decade.

The average corrosion thickness loss rate is obtained by applying equation (5) as follows:

th = [ 32.3 x 10-6 (A/cm2)-55.85 (g) ] / [ 96,500 (A.s)-2-7.86 (g/cm 3) ] = 1.189 x 10 .9 (cm / s)

t

th

-- = 0.375 (mm / year)

t

194
TableI. PolarizationDataSheet

POLARIZATION DATA SHEET TEST N° _4

REFERENCE ELECTRODE S.C. F__

WORK ELECTRODE Mild STeel

AUXILIARY ELECTRODE

ELECTROLYTE _O _

ELECTROLYTE TREATMENT l_oilec_ JOt

POLARIZATION MEASUREMENTS:

DATE o 1_?158

_.O

AREA 4_ cm2

AREA 2- cm2

pH TEMP. a_..5

CATHODIC REACTION

69 .vir_uTes -I-o reach Ecorr

CORROSION POTENTIAL: E,:o. = - 5 ?_O mv

Initial time: 5 :23 r_ Final time: 6: ?.4-(_r_ Notes

oC

1 2 3 4

I!_ 10 15 20 25

Emv -534 -543 -552 -561

11 12 13 14

I_ 80 90 100 125

Emv -750 -776 -798 -837

21 22 23 24

I t_. 400 450 500 600

Emv -1088 -1101 -1111 -1126

5 6 7 8 9 10

30 35 40 50 60 70

-571 -583 -598 -630 -668 -714

15 16 17 18 19 20

150 175 200 250 300 350

-889 -936 -975 -1029 -1052 -1070

25 26 27 28 29 30

700 800 900 1000

-1138 -1147 -1155 -1162

ANODIC REACTION

CORROSION POTENTIAL: Eco,T= - 5?_4, mv

Initial time: :F;40ptw/Final time: _ "39 r_ Notes

1 2 3 4

I_ 10 15 2O 25

Emv -515 -514 -513 -508

11 12 13 14

I!_ 80 90 100 125

Emv -500 -500 -499 -493

21 22 23 24

I_A 400 450 500 600

Emv -466 -464 -462 -457

ss r ir u' es 1-o reach F--r.o,,

5 6 7 8 9 10

30 35 40 50 60 70

-508 -508 -508 -505 -503 -503

15 16 17 18 19 20

150 175 200 250 300 350

-489 -485 -483 -478 -472 -468

25 26 27 28 29 30

700 800 900 1000

-451 -451 -448 -447

195
NOTESTO TItE INSTRUCTOR:

1. Time plays a very important role in obtaining polarization curves.

2. Repeatability requires a perfect control of the parameters involved.

3. Strictly speaking experimental polarization curves never are truly cathodic or anodic curves, they are only

applied current curves.

4. Due to the internal current effect corrosion takes place at the W.E. even under a cathodic applied current

condition.

5. For the given conditions in this experimem, currents higher than 1000 laA are difficult to control due to

the fact that external resistance should be much greater than cell resistance (Ref2).

6. Going through this basic laboratory experiment will give an elementary but solid background in the field

of corrosion testing. It is recommended before using sophisticated equipment.

. In this project and for the sake of simplicity the salt bridge, the Luggin probe, the platinum electrode and

the oxygen sensor were omitted. However each missing item was taken into account in the design of the

experiment in such a way that the lack of each one can be justified.

8. Instructors can try another electrolyte-metal combinations. Be sure to use a different graphite bar for each

different solution in order to avoid electrolyte contamination.

REFERENCES:

1. Mansfeld, F.: Don't Be Afraid of Electrochemical Techniques - But Use Them with Care!, Corrosion Vol.

44, N ° 12, p. 856, NACE, Houston, Dec. 1988.

2. Jones, Denny A.: Principles and Prevention of Corrosion, Second edition, Prentice Hall, Inc., 1996.

3. Scully, J. C.: Fundamentos de la Corrosion, 1_ edicion, Editorial Alambra, S.A., 1968.

4. Fontana, M. G.: Corrosion Engineering, 3_ edition, McGraw-Hill Book Company, New York, 1986.

5. Guichelaar, Philip J.; and Williams, Molly W.: A Simple Demonstration of Corrosion Cells, NASA

Conference Publication 3074, National Educators' Workshop: Update 89, 1990.

6. Masi, James V.: Experiments in Corrosion for Younger Students by and for Older Students, NASA

Conference Publication 3201, National Educators' Workshop: Update 92, 1993.

7. Masi, James V.: Experiments in Natural and Synthetic Dental Materials: A Mouthful of Experiments,

NASA Conference Publication 3330, National Educators' Workshop: Update 95, 1996.

8. ASTM Designation G3, Annual Book of ASTM Standard, Philadelphia.

9. ASTM Designation G5, Annual Book of ASTM Standard, Philadelphia.

10. ASTM Designation G15, Annual Book of ASTM Standard, Philadelphia.

196
ACKNOWLEDGMENTS:

The author wishes to thank Prof. Glenn H. Dewey and Prof. Mark Bloomfield for reviewing the grammar

and vocabulary of this paper and the Material's Department senior assistant Carlos Jimenez for helping in

running the experiment and preparing this paper.

The author also wishes to thank the Universidad de Costa Rica (Vicerretoria de lnvestigaci6n) and "La

Fundaci6n de la Universidad de Costa Rica para la Investigacion" (FUNDEVI) for giving financial support to

attend the NEW: Update 98.

SOURCES OF SUPPLIES:

1. Saturated Calomel Electrode

Coming Glass Works, Cat. N ° 476002, Cole Panner, Aldrich or any other scientific supply house.

2. Nitrogen Regulator

Air Products or Cole Parmer

3. Filtered DC Power Source

CPS 250 Tektronix

4. Variable Resistors and Knobs

Available from electronic parts stores

5. Sodium Chloride (99% pure or higher)

Sigma or any chemical compounds supplier

197
A C

C A

(a)

A: anodic region

C: cathodic rek, ion

(b)

Figure 1. Representation of an isolated metal or alloy that undergoes uniform

corrosion: a) Multiple anodic and cathodic micro-areas, b) Schematic

representation of the corroding electrode.

)

-IIlli --

D AUXILIARY

ELECTRODE,

A.E.

WORKING ELECTRODE, W.E.

Figure 2. Schematic representation of a corrosion system with an

external applied current.

198
Potential

E

El_cr

Ltot

-- L_, X L_, =-i

_k _ ANODIC

/_ REACTION

/c..,, _ Jl_.,_p_ ,--- CATHODIC

-. :: _ _ REACTION

Lr_

Current Density (i)

Figure 3. Schematic graphical representation of current density relations

in a polarization diagram.

Potential

E Experimental polarization /

Eeorr _ 1

Taffel extrapolation

Current Density (0

Figure 4. Schematic polarization diagram from Tafel extrapolation of

experimental polarization curves.

199
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F PTFE pipe thmod amol tope

Iii]lllliilllSlJlllJlill_Y-J'x__

= 117

L ¢_ required for a 1 _ cm working amo

(o)

Numinum rod (5/16" I))-_ _-Pk:mtic nylon tie .

\ / FNuminum ongulor (3/8 x 3/8")

\ _.jT_A,Ir- _ _'"'_'°='':,'

lllllilililllllll!_,l_.,_ Ird><J_.

Graphite Ill _

(5/16" it x 2 l/4"J

(b)

DIMENSION: mm

Figure 6. Detail of working and auxiliary electrodes"

(a) Working mild steel electrode

(b) Auxiliary graphite electrode

201
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+ Filtered Power

Supply

tM_

#2

CELL

Auxiliary Graphite

Electrode

Work Electrode

Mild Steel

<<_ 1ME_

/ #i

Reference Saturated

Calomel Electrode

Figure 7. Schematic circuitry for cathodic polarization experiment.

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2114
BIOGRAPHY

Carlos E. Umafia holds a Msc. in Metallurgy and Materials Science from Lehigh University

(77) and a Mechanical Engineering degree from the Universidad de Costa Rica (72). He is

an associate professor at the School of Mecfianical Engineering of the Universidad de

Costa Rica, where he has been in charge of courses in the fields of materials science,

strength of materials and manufacturing.

He has worked in industry and has much experience in hard chromium electroplating. As a

consulting engineer he has dealt with more than thirty cases on failure prevention, failure

analysis and accident investigation.

In the field of materials science and engineering he is ve_ interested in improving the

teaching aids of basic concepts from a multidisciplinary point of view.

2O5

THE UNDERLYING STRUCTURE OF

ENGINEERING MATERIALS

Mike L. Meier

and

Karl Ewaid

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, Califomia 95616

Telephone: 916-752-5166

e-mail mlmeier@ucdavis.edu

207

The Underlying Structure of Engineering Materials

Mike L. Meier, Karl Ewald

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, CA 95616

Abstract

This paper describes the procedure used to produce a short digital video and how it has been used in the

classroom. The video is of a tensile test of a polished brass specimen as viewed through a stereo-zoom

microscope. The subject is the relationship between structure and properties and the point being made is

that the materials have an underlying structure that determines much of how they behave. The video has

only been shown in class a couple of times and so far the results have been positive.

Keywords

Microstructure, microstructural evolution, tensile testing, digital video, deformation bands

Prerequisite Knowledge

The student should be familiar with the following:

1. Tensile testing

2. Crystal structure

3. Concepts of slip systems and critical resolved shear stress

4. The fact that many engineering materials are polycrystalline

Objectives

The objective of this paper is two-fold. The first is to offer a video to instructors that can be useful in the

classroom. It was designed to impress students with the idea that the behavior of materials is dynamic,

that materials themselves have their own characteristic structure, and that the two are intimately related.

In this case a ductile metal is used to demonstrate the relationship between the crystalline structure and

deformation processes. The second is to describe how this video was made. Digital video and video

processing is relatively easy and inexpensive and can be done on most any desktop computer. Others may

want to make their own videos of experiments that show the relationships between any number of

materials behaviors (sintering, solidification, crystallization, grain growth, dislocations, others) and the

microstructure of practically any material.

Equipment and Materials

The alloy used in this experiment was the C26000 alloy (70/30 brass, cartridge brass) which was received

in the half-hard condition. Tensile specimens were machined from the 0.125 inch (3.175 mm) thick sheet.

The gage length was 1.50 inches (38.1 mm) and the width was 0.50 inches (12.7 ram).

The equipment used to make the videos consisted of the following:

Furnace - a box furnace capable of reaching 800 °C

Tensile testing system - in this case an Instron model 4204 (computer controlled, 50 kN capacity)

209
Digital camera - a color CCD video camera with composite video output

Video Capture - several AV Macs were available but they could not provide the desired frame rate for

full size video capture. The computer used in this project was a 300 MHz Pentium II-based PC

running Windows 95. It had 128 MB of SDRAM and a 9 GB UW-SCSI hard drive capable of 17

MB/sec sustained sequential data transfer rates (per Adaptec's SCSI Bench benchmark). The video

capture board was capable of digitizing full motion video at 640x480x24 bits and 30 frames per

second (fps).

Video editing software - Adobe Premiere

Microscope - the microscope used in this experiment was a stereo-zoom microscope capable of

providing magnifications from 5 to 75X and a working distance of several inches

Illumination - quartz lamp with two fiber optic light pipes

Safety Precautions

If one is making a video following a procedure like the one given here then the usual precautions taken in

heat treating, metallography and tensile testing should be taken.

Introduction

Consider the "structure-properties-processing" principle that is the foundation of materials science. By the

time our students graduate they will appreciate this principle and will have a good understanding of its

many fundamental and practical and aspects. But in an introductory course it may be difficult to make this

point well, to impress the students that all materials have their own characteristic structure, that this

structure is dynamic and that it has direct influence on phenomenon such as plastic deformation. This

prompted the making of a short video that shows a brass specimen being tensile tested. Its purpose is to

thoroughly convince the students that there is an underlying structure (in this case a microstructure), and

not only can we see it but we can see it in action. This video can be played on most Windows-based PCs

using the standard movie player program or one can use the program I wrote that plays the video and

displays the test data simultaneously. The video, the data and the program are all available on a CDROM. This paper describes how the video was made and how it has been used it in courses.

Procedure

Heat Treating

The tensile specimens were annealed in air at a temperature of 775 °C for two hours. This produced grain

sizes of several millimeters.

Polishing the Specimens

After heat treating the specimens were mounted in a specially designed holder and ground and polished

using an automated polisher/grinder (8-inch wheels, 240-600 grit SiC, 6 _tm diamond) with the final

polishing being done using a vibratory polisher and a colloidal silica abrasive. The final results were a fiat

and nearly perfectly polished tensile testing specimen except for minor scalloping.

Tensile Testing

In the first video the specimen was tensile tested to failure using a crosshead speed of 6.00 mm per minute.

In the second the crosshead was only 0.60 mm per minute and the test was stopped long before the

specimen failed. In both tests the lower crosshead is stationary while the upper crosshead moves at the

specified rate. During the test the load-elongation data was recorded and saved to disk.

210
Video Capture

The stereo-zoom microscope was mounted

horizontally on a tripod and focused on the

center of the specimen. The video camera

was attached to the microscope's C-mount

adapter and its output was connected to the

PC, a VCR (in case the PC video capture

failed) and to a color monitor. The light

source was carefully adjusted so that it would

illuminate the polished specimen but not

reflect towards the microscope as a bright

spot. This was accomplished by adjusting

the aim of the light pipes and by placing a

diffuser (a sheet of white paper) between

them and the specimen. After making a few

short test recordings the video capture system

and the VCR were started and a few seconds

later the tensile test was started.

(640x480x24-bits, 30 fps).

300

250

5O

0.00 0.20 0.40 0.60 0.80

Strain

200

- 150

IO0

, i , , j t

1.00 1 20

Figure 1 Stress-strain curve typical of all specimens tested

during this project.

The video was recorded at the highest available resolution and frame rate

Video Processing

All video processing was done on the same PC that was used to perform the video capture. Adobe

Premiere was used to create the title screens, transitions and micron bars, to cut and splice the video and to

assemble the final video. Two versions of each video were produced, one at 320x240x24-bit and the other

at 640x480x24-bit, both at a frame rate of 15 fps. These were also accelerated so that their runtimes

would be less than five minutes.

CD-ROM

The videos, the data from the tensile tests, a Windows program that displays the video and the at stressstrain data simultaneously and a few other files (drivers, readme, etc.) were written to a CD-ROM.

Results

Mechanical Properties

Figure 1 shows the typical stress-strain curve for the specimen tested in the first video. The stress-strain

curve in the second video was similar up to a strain of 22% when the test was stopped. The yield strength

was around 50 MPa, the UTS was 288 MPa and the strain to failure was 117%.

Video 1

The first video shows a polished brass specimen being tensile tested to failure. The magnification was set

so that the specimen's width just filled the field of view and the microscope was focused on an area near

the center of the specimen. After the title slides are shown one sees the smooth yellow brass metal. As

soon as the tensile test starts the grains and twins appear and as the test continues the grains can be seen

moving off the top of the screen. Meanwhile the surface of the specimen is becoming so rough and

fibrous looking that it hardly looks like a metallic specimen at all. Finally the specimen fractures. This is

211
shown in the video as a sudden jerk of the

specimen. The video ends a short clip

showing the fractured region (figure 2).

Video 2

The second video is basically the same as the

first except that the crosshead speed using in

the tensile test was slower, the magnification

was higher, and the test was not carried out to

failure. This video clearly shows the

formation of deformation bands (figure 3)

and eventually the same grain boundary

offsets as were shown in the first video.

Windows Program

A 32-bit Windows program was written so Figure 2 The region of final fracture. This is the final

that one could show the stress-strain behavior frame in the first video.

and the microstructure simultaneously. This

program displays three child forms in a main parent form (figure 4). The child forms show the stressstrain plot, the video and text that describes the test and the video. Standard VCR-type controls are used

to start, stop and rewind the video. The plot of the stress-strain data tracks with the video.

Discussion

Some of our sophomore engineering students and visiting high school students are a little surprised to

learn that most of our common engineering alloys are crystalline. In their world "common sense" says

that crystals are rare, unusual, are somehow special and may even possess magical qualitites that can

influence our health and spiritual well-being.

At very least they should be transparent,

possibly colored and they are always brittle.

It is a pleasure to be able introduce them to

the "uncommon sense" of the scientific

world, showing them that if one looks into

the matter of crystals one may find them to

be even more fascinating and also very

ordinary. Even common metals are

crystalline! Using these videos we can show

them crystals in action in a way they had not

imagined before and then we can go on to

describe what they really are and how they

influence many of the properties we take for

granted.

In a more conventional series of lectures we

might start with a discussion the space filling

polyhedra (crystal systems) that defines and

Figure 3 Deformation bands similar to those shown in the

second video. This micrograph is from the grips section of

the specimen in first video. A metallograph was used to

take this digital photo.

212
Figure 4 Screen image of the "Underlying Structures" program. (As you can see at the

time of this writing the program is not quite finished.)

essential characteristic of crystalline materials, then the fourteen sets of points that repeat in space (Bravais

lattices) and on to our systems for specifying the locations of lattice points, of directions in the lattice, the

Miller indices of lattice planes, and eventually on to defects such as dislocations. Once the concept of the

critical resolved shear stress is presented we must somehow relate this atomic-scale shear in the crystal to

macroscopic stress and strain. At this point the student may or may not fully believe us so we show them

Bragg's bubble-raft video to convince them that dislocations really do glide, climb, etc. Next we can

show them the videos described here so that they can see that while each grain deforms in a manner

dictated its slip systems, orientation to the tensile axis and the confinement by neighboring grains and at

the same time they can see how the aggregate behavior of these grains gives us the macroscopic

mechanical properties we measure in the laboratory.

How We Have Used this Video

We have used this video in freshmen and sophomore introductory courses and we plan to try it out at the

beginning of a junior level course on dislocation mechanics/mechanical properties. In the sophomore

course our showing goes something like this:

Show the students a shiny, polished piece of brass.

Tell the students that it is crystalline but that they can't see this without first etching the specimen.

Show the students a picture of a polished and etched specimen or better yet show them a polished and

213
etched metallography specimen. Describe the major features.

Tell them that each grain has a different orientation and will slip in different directions with respect to

the direction of loading, as if each grain were a randomly oriented stack of playing cards that will

shear only in the plane of the cards.

Explain that deformation is isotropic on a microscopic scale, but because the grains are so small and

so numerous it is, in the general case, macroscopically anisotropic.

Suggest that if the grains are large enough we should be able to see each one in action.

Describe what the video will show.

Show the video.

Discuss the video.

Showing the Video in Class

The two times we have shown these videos in class we ran them from the hard drive and projected it using

an LCD projector. In both cases we showed the 640x480 format videos and the quality was very good.

The videos ran smoothly using the PC described above but if a slower PC is used and these videos do not

run smoothly then one can use the 320x240 format videos. Also, since the CPU overhead required to

operate the CR-ROM is about twice that of the hard drive we prefer to not run these videos from the CDROM.

Conclusion

Although these videos have been shown in only two classes the results have been positive. They have the

gee-wiz element that helps make the subject interesting and it also gets the point(s) across.

These videos, data, programs and the still images can be downloaded from our web site at

www.matsci.ucdavis.edu. Note that the 640x480 videos are 150+ MB files and the 320x240 videos are in

the neighborhood of 40 MB. Download times may be impractical and besides you'll need to have a place

to store these large files. If you would like to get a copy of these videos you can write or email the author

to request copies of the CD-ROMs.

Acknowledgments

Funding for this project was provided by Teaching Resources Center and the Department of Chemical

Engineering and Materials Science, both at the University of California, Davis, and by the authors.

Biographical Information

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 a two-year post-doctorate position at the Universita't Erlangen-NOrnberg in

Erlangen, Germany he returned to UC Davis where he has worked as a lecturer and as a manager for the

department's teaching and research laboratories. One of his primary duties is developing and managing

the materials science laboratory teaching program.

Karl H. Ewald received his B.S. in Mechanical Engineering/Materials Science and Engineering at UC

Davis in 1990. He continued at UC Davis for his MS and PhD in Materials Science and Engineering in

1996 and 1998, respectively. He has been teaching various engineering and computer courses at Napa

214
Valley College since 1995 and spends his summers co-teaching computer arts courses for the California

State Summer School for the Arts.

215

RENDERING ASBESTOS INTO A

NON-REGULATED MATERIAL

Leon Petrakis

Energy Efficiency and Conservation Division

Department of Applied Science

Brookhaven National Laboratory

P. O. Box 5000

Upton, New York 11973-5000

Telephone: 516-344-3037

e-mail petrakis@bnl.gov

217
Leon Petrakis

218
219
ETV /-1oLod--j

A SSE._'7-o s

l

"_o t_,_,s_

6

Or'_ .£T 0 t,,&F-. %

220
221
• Peak Production 5 x 10 6 Metric tons/year

[90% Chrysotile]

• Atmospheric Concentration

10-100 ng/m 3

5 x 103 ng/m 3 near factories

• Regulatory Agencies (EPA, OSHA)

- PEL

- ACM

0.1 fiber/cc

_>lwt%

222
AMPHIBOLES [SiO 4 Chain Structures]

• AM_O_SI3 m

m

m

Brown Asbestos

Refractive Index 1.55- 1.64

(Fe +2 Mg)7 Sis 022 (OH)2

• CROCIDOLITE m

u

m

Blue Asbestos

Refractive Index 1.69- 1.71

Na 2 Fe z+3 (Fe +2Mg)3 Sis 022

(OH)2

SERPENTINES [Layered Silicate Structures]

• CHRYSOTILE m

m

White Asbestos

Refractive Index 1.50- 1.57

Mg3 (Si2 05) (OH)4

223
SiO2 FeO

Chrysotile 39 38

Amosite 49 41 7

?

224
)

/_phil_le$

(b) ._ _ ,.:

Fig. 3. Silicate backbones of chrysotile and amphiboles: (a) the sheet silicate

structure of chrysotile, analogous to that of micas; (b) the double-chain silicate structure

found in amphiboles (12). Courtesy of Oxford University Press.

Fig. 4.

| t

/-oo ,, : "_ 6 ) v%.%

% , u.,it =., _ J,,_. %/'

\ / _"_

Microscopic strucCmre of chrysotile fibers (10). Reprinted with permission.

I

887

225
a_

oIim_

C_

oI_.1

olml

Ct_

%

226
Vol. 3 ASBESTOS 669

Fig. 5.

A • • • II

/

Microscopic structure of amphibole fibers (10). Reprinted with permission.

227
HEALTH IMPLICATIONS

1O0 A.D. Pliny the Younger comments on diseases of asbestos workers

1890-1895 High death rates among French and English asbestos weaving/cording

Asbestos workers

1927 Complete description of ASBESTOSIS (non-malignant scarring of lung tissue)

1936 Relationship between asbestos dust exposure and BRONCHIAL

CARCINOMA.

1960 MESOTHELIOMA, exceptionally rare in the gene_ public, mostly found

among asbestos workers. Cancer of the linings of thoracic or more rarely of

abdominal cavities (peritonium). Amphiboles seem to be implicated along with

respirable (<1 nm diameter) fibers. Cigarette smoking synergism.

A number of benign pleural changes (effusions, fibrosis)

228
SUPERACIDS

[Br6nsted Acid + Fluorinated Lewis Acid]

[Acidity > 100% H2SO4]

Acid Hn

H2 SO 4 -12 (Std)

Ha PO4 - BF 3 -19

HSO3F

HSOaF - SbF s

HF- SbF s

229
Patent 5,763,738 (6/9/98) (Sugama & Petrakis)

Chemical Agents for Conversion of Chrysotile Asbestos

into Non-Hazardous Materials

FSO3H [Fluorosulfonic]

F P(O) (OI-I)2

HBF4

H2Si F6

FCHzCOOH

F Cn H 4 CO OH

Fluorophosphoric

Fluoroboric

Fluorosilicic

Fluoroacidic

Fluorobenzoic

CF3 SO3 H

C2 F5 SOa H

C 5 Fll SO 3 H

C 8 F17 SO 3 H

230
-I-

.mm

231
i

4000

|iTeflumber,cm-_

I

6OO

Figure I. FT-IR absorption spectra for the O, 5, 10, and 15 w_I FSO_H-treated

¢hryso_ile asbestos samples, and _he asbesuos sample _rea_ed with

a 3 wuZ HF-14.7 w_% H2SO, solution, corresponding to _he equillbri,_m

relaulon of 15 wt% FSO_H in aqueous medium.

232
4000

Wavenumber, cm-!

FiEure 2. FT-IR speccra for 5, 10, and 15 wcZ _F- and 10 and 15 wcZ H2SO,-

treated fibers.

233
F

i p

10 15

Concentration,

Figure 3. Changes in absorbance at 3680 cm "_ for the FSO,H-, HF-, and H,S0,-

treated asbestos fibers as a function of concentration of chemical

reagents.

234
O

I

0 : Chry, otile

n : _= (Se.ai_)

• : MgSO..H_O (Kieserite)

9

0

0

3O

C, Ko2e

Figure 4. Comparison berween XRD patterns for O, 5, i0, and 15 wtZ FSO, H-¢reated

chrysotile asbestos.

235
)-

!

i

t

r"

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_., _._

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• J J

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_L.Q

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GO

(/3

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O4

ql'-'

m

m

(VwO0 L @ oes/s_unoo)/_!sue;u!

236
p

m

r

F

r

i

[

L

J

I

L

L.

F

[

\

\

\

\

\

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cO f.O ,_- O_l

0 0 0 0

c_ o c_ o

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°m

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o_

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(cLL)eu!wnml/(_oo)er!_os_l

237
0

",,3

rh

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i

f--

J

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|

h

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t

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¢

,[

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0 _ 0 0 0 0 0 0

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GO

(_

(_

"0

v

OV

u

(s;!un fueJ;!qJe)/q!suelul

238
,_

• lUlll_

mnnnnml

o pnnuul

mmmU

I!

+

opmml

,,v/

omnnq

+

+

o pmmm(

+

il

+

I

_,_

Opl_

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Opuu_

_0_

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pmnuunq

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pmmmnl

6

II

(",1

+

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oJu_

239
Z

r_

.,_

Z

0

24O
_ vv

241
XRD ANALYSES OF ITF SAMPLES

- 34 PANELS AND BEAMS

- 9 CORES FROM EACH PANEL AND BEAM

- 3 SECTIONS (DEPTH) FROM EACH CORE

- DUPLICATE ANALYSES -BNL, WRGRACE

- LABORATORY XRD, PLM, NSLS

ALL SAMPLES FOR WHICH THE APPLICATION PROTOCOL WAS

FOLLOWED SHOWED CHRYSOTILE AFTER TREATMENT TO BE < 1

WT % (VS. 12.7 % ORIGINALLY PRESENT)

NOTE: REGULATORY AGENCIES CONSIDER ANYTHING BELOW 1%

AS NON- ACM (ASBESTOS CONTAINING MATERIAL)

242
ANOTHER LESSON LEARNED: CAREFULLY STRUCTURED

COLLABORATIONS DO WORK...

- PEER-REVIEWED PAPERS AND PRESENTATIONS

- TRAINING OF POST-DOCS

UTILIZATION OF LARGE FACILITIES

- PATENTS

- SAFETY AND REGULATORY AGENCIES EARLY INPUTS A BIG PLUS

COMMERCIAL PROCESS

POSITIVE PUBLICITY

243
S TA TUS

Chrysotile (BNL, WR GRA CE Patents)

- BNL Large Scale Demos in DOE and

Federal Facilities

- WRGrace Commercialization in the Private Sector

Amosite (BNL Patents)

- US Navy, DOE, EPA, MarketSpan

244
NEWS MEDIA CONTACT:

Kara Villami], 516/344-2345

FOR _IATr_ KEL,EASE

December I0, 1997

"Brook_v_ Laboratory scicn_sts have helped _==te an irmova_i'v¢, _ soJmion to

tough problem that afl_ezs people _ound the counti3,. Tltis isju_ one =xa,,z_¢ o£many

achievements az Brook_ven, known tbr its contributiom in mecieine, basic research, energy and

environmental _i_:ce Parmer.,.hips between Department of Energy laboratories and private

industry cortsistently reap tangible rewards in this case. we will make a differerce in xtfety

removing asbestos from schc, ois. houses, offices and other building," said Secretary. of Energy

Fedm-ico Pefia.

-DOE245
ACKNOWLEDGMENTS

Collaborators

Brookhaven National Laboratory

M. Allan

N. Carciello

D. Elling

C. Eylem

A. Goland

J. Hriljac

J. Hurst

L. Kukacka

K. Lynn

L. Petrakis

W. Reams

R. Sabatini

T. Sugama

R. Webster

Q. Zhu

W.R.Grace & Co

J. Block

D. Brewer

L. Ciesluk

L. Dolhert

M. Hager

w

L. Hegedus

N. Krupkin

R. Milton

H. Mirano

D. Myers

R. Hu

246
ACKNOWLEDGMENTS -SUPPORT

The Asbestos Project was a success due also to the wonderful cooperation with, and support fi'om

others than the researchers involved, inter alia, The BNL Directorate, Department of Applied

Science, The Light Source, Physics, Medical, ES&H, Technology Transfer, DOE Brookhaven Office

and Headquarters, EPA and OSHA.

- The Director (Nick Samios) personally and others in the Directorate (Marty Blume, Peter

Bond,Mike Bebon) for general encouragement but also specific support that included key telephone

calls, LDRD support, and the availability of the Inhalation Toxicology Facility in the Medical

Department

-ES&H support and guidance with environmental and health issues and permits (J. Williams, G.

Adams, 1L Selvey, P. Sullivan); and the DAS Chairman (J. Davenport), safety personnel (P.

Carl', C.IL Krishna, J. Hurst), Administrative staff, and the secretary to the project, Gall Brown.

- Plant Engineering, especially R.Yadav

-Technology Transfer Office (P. Bogosian, M. Furey)

-D. Joel (Medical Department); D. Cox (Physics) for X7A Bearnline

-Public Relations (Kara Vfllamil, Diane Greenberg)

-DOE Brookhaven Area office staff; and at HQ's A. Claflin (ER), and C. Frank, G. Boyd, J. Hyde

(EM)

- US EPA (Tom Ripp)

- US OSHA (Dan Crane)

247

EDUCATIONAL PROGRAMS AT BNL

AND OTHER DOE LABS

Karl J. Swyler

Office of Educational Programs

Science Education Center

Brookhaven National Laboratory

Associated Universities, Inc.

P. O. Box 5000

Upton, New York 11973-5000

Telephone: 516-344-7171

e-mail swyler@bni.gov

249
Karl J. Swyler

250
251
fl

0 0

m

252
253
ml

254
0

255
256
Local Alliance Building

for

Urban Science Education

Science

Mathematics

Technology

DIl!

.t. Brookhaven National Laboratory, New York University '_

and Associated Universities, Inc.

257
PROCEEDINGS

of a conference on the integration

of

Mathematics, Science and Technology

in

precollege education.

BROOKHAVEN NATIONAL LABORATORY

UPTON, NEW YORK

JUNE 5..6, 1995

SUPPORT FOR TEllS CONFERENCE WAS PROVIDED BY

THE U. S. DEPARTMENT OF ENERGY, OFFICE OF SCIENCE EDUCATION,

AND BY ASSOCIATED UNIVERSITIES, INC.

258
BNL Face-to-Face Community Involvement

FY 1998

Program Number of Participants

Fairs & Festivals 5,513

Civic _oups/community organizations (20/month, avg. 20 participants ca.) 4,800

Summer Sundays (8 weeks) 3,256

VIP Tours 245

Special Museum tours (adults) 420

College Tours 1,236

Under_aduate Summer and Semester Students 76

Community College Semester and Mini-Semester 28

Nuclear Chemistry Summer School 12

_ •

High School Tours

Bridge Contest

Whiz-Bang Science Show (BOCES)

Community Summer Science/Academic Year Internships

Women in Science & Engineering

Minority Apprenticeships

Teacher Research Associates (summer)

547

250

50

34

30

29

2

Magnets to Go

Investigations in Science (Science Museum)

Maglev Contest

Whiz Bang Science Show

School Career Days

7,014

4,751

275

104

50

Discovery Tours (Science Museum)

Discoveries to Go

Science Fair

Science Fair Workshops (parents/teachers)

Science Exploration Days

NSF Math, Science & Technology Program (teachers)

NSF National Teacher Enhancement Internships

4,491

821

760 students/1,240 visitors

100

75

63

6

Misc. Teacher workshops and seminars 404

Mid-East Suffolk Teacher Center workshops 50

259
260
Education in Science, Technology, Energy,

Engineering, and Math

"We have to do everythingwe "...we must have a population

can to make technology fiteracy that is able and learned in the

arealityforeverychild in new technologies and

America" industries..."

.U.S.PresidentBillClinton DOE Secretary. BillRichardson

The Energy Department's Education Community

Arcade EducationPartners HighSchool

ClimateResearch ElectricBus(Transportation)House

Computer Store Elementary School

DOE Government Building Encrff¢ & Science Gallery_ Mall

DOE National Lab Gas Station Middle School

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263
Ene Research Un uate

Laboratory Fellowships

Administered by the Oak Ridge Institute for Science and Education

Program description: opportunities to participate in research relating to energy production, use,

conservation, and societal implications

Disciplines: engineering, life sciences, mathematics, physical sciences, computer science

Eligibility/participants: undergraduate students; U.S. citizens or permanent residents

Location(s): Ames Laboratory (Ames, Iowa); Argonne National Laboratory_ (Argonne, Ill.); Brookhaven

National Laboratory (Upton, N.Y.); Ernest Orlando Lawrence Berkeley National Laboratory (Berkeley,

Calif.); Fermi National Accelerator Laboratory (Batavia, Ill.); National Renewable Energy Laboratory

(Golden, Colo.); Oak Ridge National Laboratory_ (Oak Ridge, Tenn.); Pacific Northwest National

Laboratory (1Uchland, Wash.); Princeton Plasma Physics Laboratory (Princeton, N.J.); Stanford Linear

Accelerator Center (Stanford, Calif.); Thomas Jefferson National Accelerator Laboratory (Newport

News, Va.)

Duration: 10-week summer appointments or 16-week semester appointments

Deadline(s):contactProgram Manager Linda Holmes at423-576-3192 or holmesl@orau.gov

Awards made: number varies

Benefits:weekly stipendof $300; limitedtravelreimbursement (round-triptransportationexpenses

between facilityand home or campus)

Funding source(s):U.S. Department of Energy, Office of Energy Research

For more informationand an on-lineapplication,"_isitHow to Apply (http://www.orau.gov/doeerulf/).

How to Apply II Other Educational Opportunities [IORISE Home Page

A. _ Copyright 1998, Oak mdg • Associated Universities

Updated 8/18/98

264
1997 Fall Semester Student Research Presentations

Brookhaven National Laboratory

Science Education Center

December 4, 1997

9:30 a.m. Plasma Windows

Chris S. Castle

California Polytechnic Institute and

Biology Department, Brookhaven National Laboratory

10:00 a.m. Specificity of Electron Donors for Plant Fatty_ Acid Desturaseo

Alexis T. Elfieott

University of Illinois and

Biology Department, Brookhaven National Laboratory

10:30 a.m.

Inventom Data Base_for Scientific Information __ stems Grouy

David Olivares

State University of New York at Stony Brook and

Department of Applied Science, Brookhaven National Laboratory

11:00 a.m. An Evaluation of Noise Reduction Filters for Image Processin_

y

Alexandra G. Haines

University of San Francisco and

Computing and Communications Division, Brookhaven National Laboratory

265

LIQUID CRYSTAL p-AZOXYANISOLE

IN MICROWAVE FIELD

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

267
A

J. N. Dahiya

268
Liquid Crystal p-Azoxyanisole in Microwave Field

Jai N. Dahiya

Physics Department

Southeast Missouri State University

Cape Girardeau, MO 63701

e-mail:dahiya@physics.semo.edu

Key Words

Liquid Crystals, Dielectric Relaxation, Frequency Shift, Q-Change, Microwave Resonant Cavity, Field

Perturbation, Relaxation Times.

Summary

A cylindrical microwave resonant cavity in the TE0_ mode is used to study the microwave dielectric

response of liquid crystal p-azoxyanisole at microwave frequencies. The dielectric behavior of this liquid

crystal is studied as a function of frequency from 8.0 GHz to 10.2 GHz. Several undergraduate students

were involved in the design of the microwave spectrometer. This is a part of the undergraduate research

courses that the students are required to take at the physics department at Southeast Missouri State

University provided they maintain a certain GPA in their physics courses. Students were involved to

design the amplifier, marker shaper circuit, the computer interface, and the heating and cooling circuit.

The real and imaginary parts of the complex dielectric constant of this liquid crystal were calculated by

using Slater's Perturbation Equations and the relaxation time was calculated using Debye's Equation for

polar molecules.

Introduction

Liquid crystal materials generally have several common characteristics and one of the very important of

these is in terms of having strong dipoles and/or easily polarizable. Another very important property of

liquid crystals is the tendency of the molecules known mesogens to point along a common axis, called

the director. This is opposite to the behavior of molecules in the liquid phase, which have no intrinsic

order. But on the other hand, in the solid state the molecules are highly ordered and do not have much

translational freedom. The liquid crysttaline phase is between the liquid and the solid phase. It is a

distinct phase that is observed between the crystalline and isotropic states. There are four different types

of liquid crystal states: nematic, smectic, cholesteric, and columnar phases. These phases depend upon

the amount of order in the material. The response of liquid crystals to an external electric field is the

major characteristic of these materials that is used in their applications in industries. Because of the

permanent dipoles, these materials align along an external field and this behavior is further affected by

the frequency of the applied field. At lower frequencies the dipoles can follow the orientations of the

applied field without any lagging behind. But at high frequencies such as microwaves, there is a time lag

and only a certain fraction of these dipoles can follow the field and that basically determines the

electrical characteristic of that material. Even if a molecule does not have permanent dipoles it can still

be influenced by the applied field because of the induced electric dipoles. The main purpose of this

269
experiment is to study this behavior of liquid crystal p-azoxyanisole. This liquid crystal is of the nematic

type and it is characrerized by molecules that have no positional order but tend to point in the same

direction.

Wave guide techniques were used in 1960's and 1970's to study the dielectric response of materials as a

function of frequency and temperature. This technique was an approximate method to calculate the

dielectric response because of nonuniform perturbation of the microwave field. It was also very difficult

to maintain a certain temperature of the material under study. A microwave resonant cavity proves to be

a very important tool for the dielectric relaxation studies. Complex electric permittivity as well as

permeability can be studied by using such a cavity in the TE or TM modes. A similar cavity has been

used by a number of investigators for dielectric relaxation studies of a number of materials

(Ref 1-5). In this experiment a cylindrical microwave resonant cavity in the TE011 mode is used as a

probe to study the dielectric behavior of p-azoxyanisole. Dielectric response of this liquid crystal is

studied as a function of frequency. A very effective thermal bath is used to control the temperature of the

material under study. The main aim of this experiment is to establish a technique for the dielectric

relaxation studies and to involve undergraduate students in different parts of the experiment.

Experimental Design and Results

A microwave spectrometer is designed by assembling a number of electronic components together as

shown in Figure 1. A Varian klystron is powered by a HP power supply to produce frequencies between

8.0-12 GHz. The signal is transmitted through a waveguide to an attenuator that is used to adjust the

microwave power. The signal then goes to the directional coupler that divides it in two parts, a part of

which goes to the microwave resonant cavity and another part is mixed with a signal from a crystal

oscillator to produce the markers using the technique of frequency multiplication. A radio receiver

detects the difference of frequency between the signals coming from the klystron and the crystal

oscillator and produces a series of marker signals. These markers are at a fixed frequency interval. The

part of the signal that goes to the cavity is reflected and the differential display of this signal after

modulation is in the form of a butterfly. This signal is detected by a microwave diode installed in to a

detector. The signal is then amplified and displayed on an oscilloscope. A wavemeter is used to measure

the exact frequency of the klystron. The markers are used to fred the frequency shifts and the Q-changes

of the microwave resonant signal coming out of the cavity. The field patterns of the microwave resonant

cavity are shown in Figure 2. It can be seen from these patterns that as the sample under study is

introduced in to the cavity it perturbs the electric field of the cavity and as a result of that resonant

frequency shifts and the Q of the cavity changes.

The frequency shifts and the Q changes are related to the real and imaginary parts of the complex

permittivity through Slater's Perturbation Equations # 1 and 2 as shown below (Ref. 6).

Af _z'-I IL "/_ dv

fo 2 I.E..E_ dV

(1)

(2)

270
Where E, is the applied field, Es is the field ofthe sample, and E is the total field ofthe system, Afand A(ll

are the frequency shifts and the Q changes of the microwave resonant signal, 8' and e" are the real and \_dJ

imaginary parts of the complex permittivity.

The Q change is further related to the width of the signal as shown in Equation # 3 where square root of 3

is introduced because of the modulation correction. The value of the relaxation time is calculated using

Debye's Equation # 4 (Ref. 7) where e s is the value of the static permittivity at room temperature, and z

is the relaxation time.

Z (3)

-- 0)X (4)

_u

The sample under study is put in a capillary tube and this tube is introduced in to the resonant cavity

through it's vertical axis. A fixed part of the sample is introduced to cause a certain mount of

perturbation in the resonant signal as seen on the oscilloscope. The temperature of the sample is then

allowed to change by flushing liquid nitrogen cooled air around the resonant cavity. The thermocouple is

kept in direct contact with the sample to get it's exact temperature. A computer interface technique is

used to monitor the temperature of the sample as it is going through a dielectric phase change. The

thermal bath used in this experiment is very efficient to maintain a certain temperature at the phase

change.

The frequency shifts vs frequency behavior ofp-azoxyanisole is shown in Figure 3. As can be seen from

Slater's equation # 1, the frequency shift corresponds to the real part of the complex permittivity of the

material. There is a dramatic change in this behavior for this liquid crystal around a frequency of 9.6

GHz. The frequency shift drops from more than 7.0 MHz to less than 1.00 MHz at higher frequencies.

The Q change that corresponds to the imaginary part of the dielectric contant peaks out at 9.6 GHz and

drops to a very small value on both sides of this frequency as shown in Figure 4. This behavior is studied

at a temperature of 125 °C. As suggested in the theory of nematic liquid crystals ( Ref. 8), the applied

field may cause disturbances in the anisotropic phase and that-these disturbances tend to align the

molecules parallel to the field. This behavior seems to be applicable to the results shown in Figures 3 and

4. Since the walls of the resonant cavity are effective in producing an alignment, even in the absence of

an applied field there could be some disturbance present. This would tend to orientate the molecules with

their long axes parallel to the walls. The applied frequencies seem to show a parallel alignment around

9.6 GI-Iz. This indicates that at this frequency disturbances due to weak fields do not have much effect on

the alignment that is already present due to the walls. It also indicates that the anisotropy in the dielectric

constant is mainly responsible for the the dielectric loss that is observed when the microwave field is

applied to p-azoxyanisole. For this liquid crystal, the permanent dipole moment may consist of a part that

belongs to the end groups of the molecule and can rotate freely, and the other part belongs to the central

group of the molecule and is fixed in the molecule. The relaxation time for this molecule is of the order

of 4.7 x 10_ _sec. The microwave resonant cavity is very successful in identifying the phase change for

this liquid crystal.

271
REFERENCES:

i.

.

°

.

.

.

.

8.

Dahiya, J. N., "Temperature Dependence of the Microwave Dielectric Behavior of Selected

Materials," J. ofMatr. Educ., 17 (3 & 4): 215 (1995).

Hong, K. H. and J. A. Roberts, "Microwave Properties of Liquids and Solids Using a Resonant

Microwave Cavity as a Probe," J. Appl. Phys. 45(6): 2452 (1974).

Arlt, G., D. Hennings, and G. de With, "Dielectric Properties of Fine-grained Barium Titanate

Ceramics," J. Appl. Phys. 58(4): 1619 (1985).

Poirier, M., G. Quirion, K. R. Poeppelmeier and J. P. Thiel, "Microwave Study of the High-Tc

Superconductor Lal.s Sr0.2CuO4," Phys. Rev. B 36(7): 3906 (1987).

Pakulis, E. J. and T. Osada, "Microwave Absorption Studies of Y-Ba-Cu-O," Phys. Rev. B., 37 (10):

5940 (1988).

Dahiya, J. N., S. K. Jani and J. A. Roberts, "Phase Transition Studies in Polar and Non-Polar Liquids

at Microwave Frequencies," J. Chem. Phys. 74(6): 3609 (1981).

Debye, P., "Polar Molecules," Chemical Catalog, NY, Chap. V (1929).

Martin, Anna J., Gerhard Meier, and Alfred Saupe, "Extended Debye Theory of Dielectric

Relaxations in Nematic Liquid Crystals," Mol. Cryst. 4 119 (1971).

272
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276
ARTIFICIAL MICROSTRUCTURES

Mike L. Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, California 95616

Telephone: 916-752-5166

e-mail mlmeier@ucdavis.edu

277
Mike L. Meier

278
Artificial Microstructures

Mike L. Meier

Department of Chemical Engineering and Materials Science

University of California, Davis

Davis, CA 95616

Abstract

This paper describes simple methods for generating artificial, idealized micrographs which can be used in

lessons on basic stereological techniques. The micrographs are artificial in that they were generated

completely within Adobe Photoshop. They are idealized in the sense that all grain boundaries are clearly

defined, all grains are clearly resolved, and distinction between different phases is easily made. These

micrographs are suitable for exercises involving measuring grain size, grain aspect ratio, grain size and

particle size distributions, volume fraction of phases, connectivity, etc. We have used them in classroom

computer-based demonstrations using NIH Image and in home works and classroom exercises which give

the students a chance to practice the above techniques before trying them on the more difficult, real

microstructures.

Keywords

Metallography, microstructure, stereology, image analysis

Prerequisite Knowledge

The instructor should be familiar with the following:

1. Metallography and microstructure

2. Adobe Photoshop

3. Quantitative metallographic techniques such as Heyn's method (mean lineal intercept) and the point

count method for measuring volume fraction of phases

4. NIH Image, ImagePC, UTHSCSA Image Tools or a similar image analysis program, optional.

Objectives

The objectives of this paper are:

1. To demonstrate how one can use programs such as Adobe Photoshop to generate images that are good

likenesses of real microstructures

2. To offer suggestions on how one can use these artificial micrographs in classroom exercises.

Equipment and Materials

All that is needed in this exercise is a PC or Mac and Adobe Photoshop or a similar program.

Introduction

Laboratory experiments which investigate phenomena such as the Hall-Petch relationship, grain growth

kinetics, heat treatments of steel and others require that qualitative and quantitative analyses of the

microstructures be performed. A certain amount of knowledge and experience are required before on can

even identify significant features and perform the qualitative analysis. Students usually do not have much

trouble mastering this part of the analysis but considerably more experience is required when we proceed

279
with the quantitative analysis. Suddenly they find themselves making best guesses about the locations of

unresolved grain boundaries, identifying the phase of the smallest grains, separating two particles which

appear to be touching or when one is above the other as is often the case in TEM micrographs and, in

general, trying to fit the features in our real micrographs into the neat and tidy terms defined in our text

books and yet somehow keep our personal bias to a minimum. If this is disconcerting for the experienced

metallographer imagine how students feels when we equip them with the stereological, mathematical and

statistical tools necessary to be able to make reliable, unbiased measurements and then we start them off

with difficult, real microstructures.

To build confidence in these measurement methods, one could start with simpler microstructures. Or one

could forgo the time and expense of metallographic specimen preparation and instead simply sketch the

microstructures. Unfortunately, sketching a 50x50 grain micrograph per the recommendations in Heyn's

method (mean lineal intercept, ASTM Standard E 112-88) one would have to draw at least 2500 grains.

Fortunately, the personal computer can do this for us plus it can add texture and distortion effects to make

the artificial microstructure look more interesting and more realistic. All of this can be done using Adobe

Photoshop or a similar program. No programing on our part is necessary.

Procedure

The following is the procedure for generating a basic microstructure for a single-phase material. This is

followed by variations on this procedure which can be used to generate duplex, cold worked and

recrystallized microstructures. All of the procedures described here take advantage of Adobe Photoshop's

layering feature. Therefore Photoshop version 3.0 or higher is required. (We found layering in version

4.0 to be easier to use.) Version 4.0 was used to generate the micrographs in this paper so the procedures

given here are for Photoshop version 4.0. The text in italics refers to specific menu items in Photoshop

version 4.0.

Generate the Basic Mierostructure

The procedure described here illustrates the basic method for generating artificial B/W micrographs.

Figure 1 shows the image generated at each step.

Create a New Image Create a new image of appropriate size, type and resolution (file: new). One might

want to generate grayscale images up to 8"xl 0" at 600 pixels per inch (ppi) for use

by the students. Unfortunately, this image requires 28.8 MB of memory and disk

storage as well as significant processing and printing time. Therefore we use smaller

images, such as 4.5"x6" at 300 ppi (2.37 MB) to develop a new type of

microstructure and then we repeat the procedure to generate the final, larger image.

Add Noise Use the noise filter (filter: noise: add noise) to darken the blank image. Note that

this noise is being applied to the background layer of the new image. Optionally,

you can render clouds (filter." render: clouds) to create dark and light areas.

Crystallize Duplicate the background layer and use the crystallize filter (filter: pixelate:

crystallize) on this new layer to produce the grain-like image. You can specify

grain size but not the shape. The grains will be equiaxed, fairly uniform in size and

generally 5 or 6-sided polygons.

280
Grain Boundaries

Note: for good statistics Heyn's method of measuring grain size the test line should

intersect at least 50 grains.

Finally, adjust the gray levels (image. adjust." levels) to darken and lighten grains or

image. adjust." brightnesscontrast to achieve the desired effect.

Duplicate the crystallize layer and use thefind edges filter (filter: stylize:find

edges) to extract the grain boundaries. Adjust the brightness and contrast to achieve

the desired effect.

DIC Effects Duplicate the crystallize layer again and use the emboss filter (filter. stylize:

emboss) and the bas relief filter (filter. stylize." bas relic3') to generate offsets at the

grain boundaries and then use the texturize filter (filter." texture: texturizer) to give

the grains a sandstone-like texture.

Blend Layers Adjust the opacity of each layer to achieve the desired effect. Also, experiment

with the layering option: normal, multiply, difference, etc. and with the order, top to

bottom, of the layers.

You will have to flatten this image before exporting it as a tiff file or any other type of bit mapped image.

The above procedure is not the only way to generate a crystallized structure. For instance,filter: texture:

stained glass will also produce polygons with outlined grains. This filter will let you adjust the thickness

of the grain boundaries.

Specific Types of Microstructures

The following procedures provide guidelines for generating specific types of microstructures.

Single Phase

The basic procedure described above produces images which look like single phase microstructures.

Try readjusting the opacity of various layers and even tum off some of them to emphasize the grain

boundaries, the tinting of each grain, etc. (figure 1)

Duplex Structures

Use the threshold feature (image: adjust." threshold) on a duplicate of the crystallized layer to convert

it to black and white patches. Rename this layer the "Second Phase" layer. Duplicate the crystallized

layer again and use thefind edges filter to produce the grain boundaries. Make the crystallize layer

invisible and blend the "Second Phase" and "Edges" layers to obtain the desired effects. (Figure 3)

Cold Worked and Recrystallized Microstructures

Once you have a crystallized image you can resize it to elongate and/or flatten the grains. Afterwards

you can generate the grain boundaries and DIC layers as desired. To "recrystallize" this

microstructure simply apply the crystallize filter again to the flattened grains layer but this time

specify a smaller grain size. To represent a "grain growth anneal" you can use the crystallize filter

again on the recrystallized image and specify larger grains. This technique can produce impressive

281
results: strings of dark and light equiaxed grains characteristic of a banded microstructure, even after

extensive "annealing". (Figure 4)

Super Alloys

You can use the mosaic tiles filter to create a superalloy-like microstructure. This will produce an

array of squarish grains in a matrix phase. It may require some imagination to see this as a typical

y/y' structure. One could use it as an example of a composite material.

Results

Figure 1 shows the individual layers and the final blended image described in the basic procedure. This

would pass as a reasonable representation of aluminum, copper, austenitic stainless steel only without

twins.

Two examples of two-phase microstructures are shown in figures 2 and 3. Figure 2 shows dark inclusions

in an unetched matrix. The inclusions we produced using the plaster filter. Figure 3 shows a micro-duplex

microstructure. It was produced by blending a threshold layer with afind edges layer, both derived from

the same crystallized layer which in turn was based on an original render clouds layer. One can use these

microstructures in exercises involving the measurement of grain size, particle size and volume fractions

of phases, connectivity, contiguity in duplex microstructures.

Figure 4 shows a series of artificial microstructures starting with the as-received microstructure, followed

by the cold worked microstructure, and then the subsequent microstructures produced by annealing at

higher and higher temperatures. In this case the flattening of the grains was done by resizing the original

image but one could also use a distortion filter instead to simulate the effect of bending on the

microstructure.

Discussion

In our laboratory experiments we still use the manual methods for counting grain intercepts and point

counts (volume fraction measurements) but we use spreadsheets and other programs to handle the math.

The students try out the these techniques using the artificial micrographs (figure 5 is one of the images we

use) before they analyze the real microstructures. This type of rehearsal has been invaluable in the

experiments where each student analyzes a couple of specimens and then shares their results with the

whole class so that everyone can complete their investigations of the grain growth kinetics of C26000

brass, the Hall-Petch relationship for this same alloy, or to investigate the relationships between

processing properties and microstructure for plain carbon steels.

Once the students are familiar with basic quantitative metallographic techniques one can demonstrate

more advanced image enhancement and analysis techniques using commercial programs such as Image

Analyzer Pro or the freeware program from NIH called Image. The artificial micrographs produced by

the methods described here make good clean images which one can use to demonstrate image analysis

procedures such as Fourier filtering, erosion and dilation, and thresholding. Next one can perform the

analysis by measuring the mean grain size, obtaining histograms of the grain sizes, measuring the volume

fraction of phases and even the particle size distributions using the Johnson-Saltykov method, analyzing

the shapes and orientations of grains, and measuring the connectivity and contiguity in duplex structures.

282
In mostcasestheinstructorwill probablybetheonewho generatesthemicrostructures(thefun part)that

studentsanalyze.Sincethesearenot realmicrostructuresthe studentwill not learnaboutanythingreal

materialsbuttheycanlearna numberof valuablelessonsbeyondgainingproficiencywith specified

stereologicaltechniques.A few of themare:

° The nature of the measurement techniques: Stereology is a combination of the probability, the

topological characteristics of the microstructural feature being measured, and the statistics related to

our sampling techniques that yields a valid, unbiased and accurate measurement.

, The value of validated, standardized techniques: The student should learn that only if employed

correctly will everyone get the same result. From this point on in their work and their research they

should be on the alert for indications that the methods other authors used were the proper techniques

and that they were employed correctly.

° Different techniques can be employed to measure the same thing: If the techniques are unbiased and if

they are employed correctly they should give the same result. However, one should still pay careful

attention to how the feature to be measured is defined.

Conclusion

The micrographs produced using the method described above are quite adequate for classroom exercises

where the objective is to master the stereological techniques one will use in a real experiment.

Photoshop's filters make if possible to go beyond making simple, fiat sketches of grain outlines. The

added degree of realism makes for more interesting micrographs and more credible exercises.

Biographical Information

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 a two-year post-doctorate position at the Universit/it Erlangen-Nttmberg in

Erlangen, Germany he returned to UC Davis where he has worked as a lecturer and as a manager for the

department's teaching and research laboratories. One of his primary duties is developing and managing

the materials science laboratory teaching program.

283
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284
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representing a duplex microstructure.

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287

CRYSTAL GROWTH

Merrill Rudes

Director of Product Development

Energy Concepts, Inc.

595 Bond Street

Lincolnshire, Illinois 60069

Telephone: 847-821-1900

e-mail ECIENG1 @AOL.COM

289
Merrill Rudes

290
Crystal Growth

Merrill Rudes

Energy Concepts, Inc.

Lincolnshire, IL

Keywords:

Crystal, Chemical Reaction, Melt, Crystalline Solid, Amorphous Solid, Atoms, Molecules, Ions,

Crystal Lattice

Prerequisite Knowledge:

The student:

1. should know that solids occur in the form of crystalline or amorphous structures.

2. should know that crystalline solids exhibit a repetitive, geometric arrangement of atoms, ions,

or molecules.

3. should know that the crystalline structure is responsible in part for the properties and the

appearance of many materials.

Objective:

The objective of this experiment is to demonstrate that crystals grow in a regular manner. The

result of this growth is a solid with repetitive geometric structures. "A true crystalline solid

possesses an ordered, three-dimensional, geometric arrangement that repeats itself." Jacobs and

Kadoff (1), Engineering Material Science Technology. Two methods of growing crystals will be

shown in this experiment.

The student will learn:

1. to grow crystals from a melt.

2. to grow crystals from a chemical reaction.

3. to observe the shape of different crystal structures.

Equipment and Supplies:

1. Copper Wire

2. Microprojector or Video Camera with Microscope Adapter (if done as demo)

3. Microscope

4. Microscope Slides

5. Phenyl Salicylate

6. Silver Nitrate, .01 M

7. Heat Source (i.e. Lighter, Match, Bunsen Burner)

8. Forceps

9. Bulb Pipette

291
Experiment/Demonstration Overview:

Many elements and compounds have crystalline structures. These crystal structures have

particular properties associated with them that can be used to help identify them. These are size,

shape, and unit cell type. The crystal of a particular material witl always grow with the same

angle and shapes.

"In the ideal crystal, the atoms or ions take on a definite ordered structure." Booth (2), Material

Science Technology, Solids. If the atoms did not take on a random, ordered structure, the

material would not be crystalline. It would be amorphous. The pattern these particles form is

called the crystal lattice. The crystal lattice of a particular material results in the particular shape

of the crystal. The manner in which the crystals of a material are packed together govern many of

the properties of that material. Examples of these properties are malleability and ductility in

metals.

Crystals can be formed in nature or in the lab in several different ways. For example, a crystal

may be formed by evaporating a saturated solution, a chemical reaction, or cooling a molten

substance to a solid. This can be seen in the formation of salt (sodium chloride) via the

evaporation of a solution, i.e., oceans or salt lakes, and during the cooling of a molten iron which

results in the formation of a crystalline metal.

In many cases, observing crystal formation is difficult. Crystals form at varying rates. As a result,

the time required may be too fast or too slow for normal observation under a microscope.

Temperature also affects crystal growth. An environment that is too hot or too cold for standard

laboratory observations can not be safely duplicated in a laboratory environment.

This experiment will allow students to observe crystals while they are growing. Two different

methods of crystal growth will be observed: a melt process using phenyl salicylate and a heat

source; and a chemical reaction process using copper wire and silver nitrate.

Procedure:

Crystal Growth by Melt

1. Obtain a clean microscope slide.

2. Place a small amount of phenyl salicylate on the center of the slide.

3. Carefully heat the slide to just melt the phenyl salicylate.

4. Allow to cool while placing the slide onto the microscope. Adjust the microscope to observe

the melted phenyl salicylate.

5. Use the forceps to add a single grain of phenyl salicylate to the melt. The crystal should

immediately start to grow. If the grain melts allow the melt to cool and repeat the process.

6. Observe the crystal's growth noting the shape of the crystals and what happens when separate

crystals interact. When observations are completed replace this slide with a clean slide.

292
Crystal Growth by ChemicalProcess

1. Place a small piece of copper wire on the clean slide and adjust the microscope.

2. Place one or two drops of silver nitrate solution onto the copper wire. Crystals should start to

grow immediately. Once again observe the shape of these crystals and how they interact.

3. Wipe both slides with a paper towel and dispose of the paper towel in the solid waste

container.

Summary:

This experiment has demonstrated two different methods by which crystals may be formed: the

chemical reaction process and the melting process. The melt crystal formed when a heated

solution cooled and was seeded with a grain of solid. The result was the rapid formation of

crystals. These crystals had shapes that were similar to each other in individual shape but formed

different surfaces when they interacted with each other. The chemical reaction resulted in crystal

growth when silver nitrate was added to a piece of copper wire. The silver crystals grew as a

result of a single replacement reaction. The copper was more reactive than the silver. The copper

atoms therefore gave their electrons to the silver ions from the silver nitrate. The silver and

copper switched places. Silver crystals were formed and copper went into the solution to form a

copper nitrate solution.

Comments:

This experiment is one of 28 demonstrations and 66 experiments that are part of the Energy

Concepts Incorporated Material Science Technology course. "Material Science Technology" is a

complete turn-key learning system including curriculum, lab equipment, and supplies. This

course is appropriate for implementation at secondary schools, community colleges, or

institutions intending to offer a program that builds a foundation in Material Education. For

information, contact Energy Concepts Inc., 595 Bond Street, Lincolnshire, Illinois, 60069.

293
References:

1. Jacobs, J.A., and Kidduff, T.F., Engineering Material Science Technology, Third Edition_

Prentice Hall, 1997, pp 93.

2. Booth, Len, Material Science Technology, Solids, Energy Concepts, Inc., 1996, pp 3-7.

Acknowledgments:

The author received assistance from Len Booth, author of Material Science Technology, James

A. Jacobs, author of Engineering Material Science Technology, and Amalia D. Parthenios, Editor

at Energy Concepts, Inc.

294
SIMULATING OPTICAL CORRELATION ON A PC

B. F. Draayer

Physics Department

Southeast Missouri State University

One University Plaza

MS 6600

Cape Girardeau, Missouri 63701

Telephone: 573-651-2391

e-mail draayer@physics.semo.edu

295
B. F. Draayer

296
Simulating Optical Correlation on a PC

By Bret Draayer

Physics Dept., Southeast Missouri State University

One University Plaza; Cape Girardeau, MO 63701

KEY WORDS

Correlation, Spatial light modulator, Composite filter, True class, False class

OBJECTIVES

1. Describe optical correlation and explain its relevance to material science.

2. Show how to simulate correlation on a PC and present simulation results.

3. Advocate correlation as a good subject for undergraduate research.

ABSTRACT

Mathematical correlation is often a useful tool to exploit in pattern recognition

applications. Correlators have many desirable features that make them well suited for

recognition systems; however, it is sometimes difficult to elicit reliable performance from

correlation systems because slight changes in an object's orientation can significantly

degrade correlation peaks. To overcome this problem, filters that represent multiple

views of one or more objects, so called composite filters, have been designed for use in

correlation systems. In this paper, the author explains how to use cheap, commercially

available equipment to simulate optical correlation on,a computer. Furthermore, this

paper discusses how to design and construct a specific Composite filter known as the the

equal correlation peak synthetic discriminant function. Using simulations, the author

discusses the characteristics of this composite filter, as well as its ability to provide

rotationally invariant responses in a coherent optical correlator. Finally, plans for

building other types of filters are presented, as is an endorsement about why correlation

represents a good avenue for undergraduate research.

BACKGROUND

Figure 1 depicts the overall operation of a correlation-based recognition system. The

basic idea is that a scene, which may or may not contain an object of interest, is

correlated against a filter and the resulting correlation pattern is observed or captured for

computer analysis. When an object in the input scene and the object(s) represented by the

filter match, we should get a bright peak in the correlation pattern. When a weak peak

297
observed, we can infer that no object in the input scene matches the object(s) represented

by the filter. A big part of the correlation-based recognition game then is deciding how

strong a peak should be to count as a match. Figure 1 shows the classical 4f correlator in

which the four essential elements of the correlator are all separated by one focal length;

however, many other architectures exist [11.

To encode information in optical form, a scene is imprinted onto a laser beam by

passing it through a computer controlled spatial light modulator (SLM) such as a liquid

crystal TV. Spatial light modulators can be complex devices, but their operation in a

correlator is fairly simple. Essentially, they function as a regular rectangular grid of

electronically addressable pixels, with each pixel being capable of adjusting the plane of

polarization of input light. Thus, when used in conjunction with a polarizer, they can

pass, block, or partially attenuate input light, depending on how the transmission axis of

the polarizer is aligned. As shown in Figure 2, the projection of the plane of polarization

onto the transmission axis of the polarizer determines the degree of attenuation of input

light.

Understanding how a correlator works is made simpler if one considers their

operation in the spatial frequency domain. A lens takes a 2-d Fourier Transform of the

input scene, which, in the classical 4f correlator, appears a distance of one fooal length

away from the lens. At the plane of the Fourier Transform, a second SLM filters the

spatial frequency components of the imprinted scene by exploiting the relationship that

correlation in the spatial domain is equivalent to multiplication in the frequency domain.

A second lens then takes an inverse Fourier Transform of the Fourier Transformed scene

multiplied by the transfer function written to the Fourier SLM, and the final correlation

pattern appears a distance of one focal length away from the second lens.

If the filter represents a single view of a single object that is present in the input

scene, as is the case in the matched filter [2] for example, then the correlation peak is very

bright and is easily distinguishable from non-matching peaks. Physically what is

happening in the case of a match is that the Fourier SLM takes a complicated wavefront,

the Fourier Transform of the input scene, and rotates the plane of polarization at each

pixel such that the exiting wavefront is planar. The fmal lens then focuses this plane

wave to a bright point a focal length distance away. When a composite filter is used

instead of a matched filter, the exiting wavefront is made nearly planar, and the sharpness

of the resulting correlation peak is an indication of how closely the exiting wavefront

resembles a plane wave, and, consequently, how well an object in the input scene

matches the object represented by the filter.

COMPOSITE FILTERS

As noted earlier, a correlator will usually produce bright peaks when a filter is simple;

i.e., when it represents a single view of an object. Unfortunately, when the object that a

simple filter represents is subjected to small geometric distortions, correlation peaks tend

to degrade. For example, a 2 ° difference in in-plane rotation between a simple filter and

the object it represents can cause the correlation peak to decrease by as much as 50% [3].

Variations in size and viewing angle also cause similar decreases in correlation peaks.

298
Suchsensitivityto geometricdistortionsisnoproblemif objects of interest are always

viewed from the same perspective, with very little variation in size and shape. Indeed, it

is often desirable. For example, when evaluating whether or not the size of parts fall

within acceptable tolerances, we can correlate the image of a potentially defective part

against the image of a standard-sized part and use the resulting correlation peak as a

measure of how much the two parts differ in size. However, we likely do not care about

the orientation of either part in this type of scenario. Thus, the sensitivity of simple filters

to in-plane rotation could present a problem. To overcome this problem, we have two

choices. One choice is to correlate the image of the part under test against several filters,

each one representing a slightly different orientation of the object of interest, and assume

that the brightest peak produced corresponds to when the filter and object are in the same

alignment so that the degradation in peak value is due solely to size discrepancies. A

negative side effect of this procedure is that it slows the system down in direct proportion

to the number of filters used to represent an object. Our other choice is to use composite

filters which represent multiple views of a single object, or even multiple views of

multiple objects.

One of the simplest composite filters to build is called the synthetic discriminant

function equal correlation peak filter, or ECP SDF filter. Historically, filters were

designed to differentiate one class of objects, called the true class, from another class of

objects called the false class; consequently, the ECP SDF design procedure will presented

in this context. All filter design processes start with a set of training images (TIs) that

must be representative of the distortions in images that the filter is likely to encounter.

For example, imagine we were trying to identify the class of an object placed on a table

and viewed by a camera directly overhead. In this scenario, changes in scale and

perspective would be negligible, and the system would only have to contend with

variations in in-plane rotation. Ideally, images of true-class objects should trigger a

recognition response from the system, whereas images of false-class objects should not

trigger a response even though the false-class object may closely resemble the true-class

object. In a scenarios involving two or more target classes, it is important to include

false-class training images in the filter design process to lower the filter's susceptibility to

producing false alarms; i.e., indicating the presence of a true-class object in an input

scene when a false-class object is actually present.

It should be noted that it is customary to place the center of mass of TI objects at the

center of the image, or origin of the image. We do this because correlators are naturally

shifl-invariant linear systems; i.e., correlation patterns shift in direct proportion to shifts

in the location of input objects. Thus, if we correlate a simple filter against a matching

object that has been shifted away from the origin, we will fred that the correlation peak

shifts away from the origin of the correlation plane by a corresponding amount. If we do

not center the TI objects, the peaks will still shift with shifts in input, but the shift will not

be relative to the image center, which is usually inconvenient. Moreover, for some

popular types of filters, non-centered TI objects cause two correlation peaks to appear in

the correlation pattern [4]. Finding the center of mass of TI objects is generally easy

because the objects are typically imaged against a dark background (or light background

in the case of dark objects), and are easy to segment.

299
MATHEMATICAL DEVELOPMENT OF THE ECP SDF

In most applications, each TI is a digital image composed of m x n pixels; thus, each

TI can be represented as a 2-dimensional array. Assume an integer number of TIs, say N,

are chosen to comprise the TI set, and let the ith TI be denoted as t i (m, n), where m and n

are row and column indices, respectively. In the ECP SDF formulation, a filter is

assumed to be a linear combination of TIs. In other words, ifh(m,n) represents a filter,

we may write:

N

h(m,n) = Eai x ti(m,n), (1)

i=1

where a i is a possibly complex-valued constant. It is convenient to express Equation (1)

in vector form. To do this, we lexigraphically reorder h(m,n) by stacking successive

columns to create a vector, h, with m x n entries. We also lexigraphically reorder the TIs

and define S as the (m x n) x N matrix whose ith column is the ith TI. Using this

notation, Equation (1) becomes:

h = Sa, (2)

where a is a N-element vector whose ith value is a i. Now we exploit a useful property;

namely, that the origin value in the correlation plane is equal to the inner product of two

vectors. One vector is the lexigraphically rearranged input scene and the other is the filter

vector. To come up with an expression for the filter function, the designer specifies the

correlation value at the origin for each TI. In vector form, this is done via the equation:

Srh=c, (3)

where c is an N-element vector whose ith value is the designer-specified correlation

origin value when the ith TI is correlated against the filter h. We now substitute Equation

(2) into Equation (3) with the result:

S r Sa = Ra = c ,, " (4)

where R is the N x N correlation matrix whose ith, jth value equals the origin value in the

correlation plane when the ith TI is correlated against thejth TI. Thus, it is also equal to

the inner product between the ith TI and thejth TI when each one is represented as a

vector. Note that R is a symmetric matrix. Solving for a, we finally end up with the

solution:

a = g-lc. (5)

Generally, the designer chooses large correlation values for the true-class object and

low correlation values for the false-class object with the hope that non-TI images of trueclass objects will yield high enough peaks when correlated against the filter to distinguish

them from peaks produced by non-TI images of false-class objects. One shortcoming of

the procedure is that only the origin correlation value is controlled in the design process

so it is not uncommon to produce peaks elsewhere in the correlation plane that exceed the

300
origin value,makingit difficult to differentiatebetweentrue-classandfalse-classpeaks

with a crispthreshold.Anotherproblemwith compositefilters is thattheyhavea

tendencyto losespecificityastheybecomemorecomposite.In otherwords,it is more

difficult to maintainasignificantdifferencebetweentrue-classpeaksandfalse-class

peaksastherangeof distortionsrepresentedby the filter increases.As notedearlier,the

ECPSDFis only onetypeof filter thathasbeendesignedfor usein opticalcorrelators,

andmanysuperiorfilter typesexist [5]; however,thispaperwill not addressthesemore

complexfilter designs.

SIMULATING OPTICAL CORRELATION ON A PC

For people who want to experiment with correlation but do not have the funds, time,

or wherewithal to build an optical system, it is fortunate that a host of companies now

produce frame grabbing/image processing boards that make simulating optical correlation

easy. Companies such as EPIX, DIPIX, and Matrox, among others, build affordable

boards that are designed to reside in a PC. A good board for simulating correlation

should come with software that performs 2-dimensional Fourier Transforms, image

addition, image rotation, convolution, and multiplication of complex images. Several

boards are capable of performing correlation as it is mathematically defined, but it is still

essential to have the previously listed features for designing filters even with correlation

capable boards. Finally, the software accompanying the boards should be able to save

images in different formats, such as text, TIFF, PCX, etc., since the processing for some

of the more complicated filters is probably best done using a sophisticated program such

as MATLAB [6], and having the ability to save images in different formats makes it easy

to exchange data between different programs.

To produce simulations for this paper, an EPIX board called the 4MEG12 [7] was

used to grab images, perform 2-d FFTs, and scale gray level values in images by a

constant; furthermore, students programmed the board to automate the data collection and

filter synthesis process. To design ECP SDF filters, we selected 9 images from a true

class and 9 images from a false class. Figure 3 shows the reference true-class image on

the left and the reference false-class image on the right. We generated TIs by rotating the

reference image for each target class in 5 ° increments over a 40 ° span. An ECP SDF was

designed by computing the correlation matrix defined in Equation (4), finding its inverse,

and multiplying the inverse by the vector of designer specified constants. For true-class

images, we chose an origin correlation value of 100, and for the false-class images, the

origin value was chosen as 20.

In the frequency domain, the filter represents a transfer function. In the spatial

domain then, the filter represents an impulse response. Once we have determined vector

a of Equation 2, we can fred the impulse response by forming the sum in Equation 1.

Figure 4 shows the resulting impulse response. As can be seen, several rotated versions

of the two reference objects are clearly present. To produce simulation results, we take

the Fourier Transform of the impulse response to get a transfer function. We then

multiply the Fourier Transform of an input scene by the transfer function represented by

301
thefilter andtakeaninverseFourierTransformof theproductto generateacorrelation

pattern. We couldrepeatedlyperformtheshift,multiply, andaddoperationsthatdefme

correlation,but this is usuallya muchslowermethodto useondigital computers.

To test the filter, we first correlated it against TIs to check the agreement between

experiment and theory; i.e., we checked how closely actual correlation values matched

the designer specified values held in vector c. These tests revealed expected

results---peak values for the true-class objects and center-of-mass correlation values for

the false-class objects were almost always within 90% of the specified values. Also as

expected, it was found that peak correlation values for false-class objects often did not

coincide with the center-of-mass of input objects, but were still low enough to permit one

to identify the object class by thresholding the peak value. For non-TI images,

correlation peaks for true-class objects varied according to how much the rotational offset

of the image differed from the rotation angle of the most closely aligned TI. Figure 5 is a

plot of peak value versus object rotation from zero to 45 °, with the top plot showing the

response of true-class objects and the bottom plot showing the response of false-class

objects. Note the fluctuations in the top plot have a period equal to the separation in

rotation angle between successive TIs. Also note that distinguishing true-class objects

from false-class objects could easily be accomplished by simply thresholding the peak

value.

CONCLUSIONS

Correlation is a useful mathematical operation that can be exploited to solve problems

in diverse situations. It has been successfully applied to problems involving target

recognition systems, but it may also be of value to the field of material science, even

though not much work has been done in this area to date. It represents a good research

area for undergraduate students because it nicely illustrates the fundamentals of system

design, optics, and image analysis, yet it doesn't require expensive equipment.

Furthermore, students can come to speed on the subject fairly quickly. It does not take an

inordinate amount of time for students to get to the point where they can perform some

non-trivial experiments, which is important in undergraduate research. It is disappointing

to get students to a position where they can contribute to a research project, only to have

them graduate. Finally, correlation represents a research area in which students can build

upon the work of earlier students. For example, students have written routines to build

ECP SDFs, to correlate filters against input scenes, and to evaluate filter performance by

collecting and analyzing data in an automated sequence for the EPIX board mentioned

earlier. Future students may write routines to construct other varieties of filter functions,

but they can still use the correlation and testing procedures written by the students that

came before them. The filter design processes are often modular in nature, so that one

student can work on a small part of the overall process and then combine it with the work

of other students to complete a larger project. Thus, using correlation, an investigator can

generate plenty of good research projects with a modest investment in equipment.

3O2
AlthoughtheECPSDFwasperfectlycapableof distinguishingbetweentrue-class

objectsandfalse-classobjectsin thesimplisticscenariogiven,it shouldbekeptin mind

thatautomatedrecognitionsystemsoftenmustcontendwith morechallengingscenarios,

andhencerequiremoresophisticatedfiltering techniques.Futureundergraduatestudents

will work ondevelopingcircularharmonicfilter routines,minimum averagecorrelation

energyfilter routines,andothers.Furthermore,applicationsfor materialsciencemay

requirenovelfiltering techniquessincethedifferencein objectivesbetweenmaterial

scienceandpatternrecognitionis fairly broad;however,someimportantinvestigations

mustbecompletedbeforesuchaconclusionisreached.

3O3
.

.

.

.

.

.

7.

REFERENCES

Brett D. Bock, Thomas A. Crow, and Michael K. Giles, "Design considerations for

miniature optical correlation systems that use pixelated input and filter transducers,"

SPIE Proc., Vol. 1347, pp. 297-309, 1990.

Jack Gaskill, "Linear Systems, Fourier Transforms, and Optics," John Wiley and

Sons, New York, pg. 261, 1978.

Gary W. Carhart, Bret F. Draayer, and Michael K. Giles, "Empirical Performance of

Binary Phase-Only Synthetic Discriminant Functions," SPIE Proc., Vol. 1564, pp.

348-362, July 1991.

Fred M. Dickey, K. Terry Stalker, and J. JeffMason, "Bandwidth considerations for

binary phase-only filters," AppL Opt., Vol. 27, No. 18, 1988.

B. V. K. Vijaya Kumar, "Tutorial survey of composite filter designs for optical

correlators," Appl. Opt. 31, No. 23, 1992.

MATLAB, student ed., Prentice Hall, Englewood Cliffs, N J, 1997.

EPIX Inc., 381 Lexington Drive, Buffalo Grove, IL 60089, Tel: (847) 465-1818,

email: epix@epixinc.com.

304
Input 5LM

Collimate_l

Laser

Light

I

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I

z

f f f f '

Figure 1: Classical 4f correlator.

305
White

Input

Polarization Direction

Transmission Axis

Figure 2: Intensity modulation using a SLM and a polarizer.

306
(a) (b)

Figure 3: (a) True-class reference object, & (b) False-class reference object.

307
Figure 4: ECP SDF filter.

3O8
Truej

False.

J

100

8O

40

Figure 5:

20

0 I I I I

0 10 20 30 40

Peak correlation value versus rotation angle for true-class (top) and

false-class (bottom) objects.

309
Bio:

Bret Draayer attended New Mexico State University where he received a Ph.D. in

electrical engineering in 1993. He worked in industry for three years on projects

involving image processing, telescope optics, and signal analysis. He is currently a

professor in the Physics Department at Southeast Missouri State University, where he

teaches courses in physics, circuit analysis, digital electronics, and capstone design.

310
TRENDS FOR AUTOMOTIVE MATERIALS

John E. Fillion

Senior Manager

Body Materials Engineering

DaimlerChrysler Corporation

800 Chrysler Drive

Auburn Hills, Michigan 48326-2757

Telephone: 248-576-7472

e-mail jef2@chrysler.com

311
John E. Fillion

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MACROMOLECULAR ARCHITECTURE

Donald A. Tomalia

Michigan Molecular Institute in Midland

1910 West Saim Andrews Road

Midland, Michigan 48640

Telephone: 517-832-5555 ext. 601

e-mail tomalia@mmi.org

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TUTORIALS

for

INTRODUCTION TO MATERIALS ENGINEERING

Charles J. McMahon, Jr.

University of Pennsylvania

Department of Materials Science and Engineering

3231 Walnut Street

Philadelphia, Pennsylvania 19104

Telephone: 215-898-7979

e-mail: cmcmahon@lrsm.upenn.eou

351

Tutorials

fOE

Introduction to Materials Engineering

Charles J. McMahon Jr.

Dislocations and

Crystal Plasticity

,i Phase Diagrams

•, Magnetic Materials

Electronic Materials

Interactive G Iossa ry

Animation Viewer

M_KFON

Illustrated Review Booklet

MEDIA

353
Order from:

Merion Books

Whitman Distribution Center

10 Water Street

Lebanon NH 03766

FAX 603 448 2576 Phone 800 353 3730

Student price: $18.75

Acknowledgments

This work was supported mainly bv the National Science Fc)t, ndation under grant no.

1)UE-94-55333. Videos wcrc contributed by Pr_dcssor Ian Robc,'ts_m of thc Univcrsitv _t

- °

Illinois, I_r{dcss_n • K. ,-\. Jackson _t" the University c_f Ariz_ma, l)r. I-h_ward Licbcrman {_t

_) "(.TtT the Allied-Signal Cotporati_m. and bv rcxas Instrt, mcnt C_rporati_m. Clips from the bra._.,

and Nvc bubblc m{)x'ic were also used.

"['his b_oklct was created bv Asha Maliakal and Scamus Woods

354
Inside the Tutorials

l)islocations and Crvstal Plasticitv

Slip in FCC Crx'stals

Types ()f I)isl()c=tti(>ns

Observati()n of Dislocations

Crystal Plasticity

Stress Fields of Dislocations

Ener&' of Dislocations

Mechanism of Strain Hardening

Phase Diagrams

Brazing, Soldering, and Wetting

Lowering the Melting Temperature

A Simple-Eutectic Phase Diagram - The Lever Rule

A Simple-Eutectic Phase Diagram - Microstructures

The Phase Rule

Brazing of Bikes

Magnetic Materials

Recording and Magnetism

Types of Magnetic Behavior

Domain Wall Motion

The Tape Head

Recording Tape

Motors and Headphones

Electronic Materials

I n t roducti on

Electrical Conductivitv

Semiconductors

Purification and Crystal Growth

Silicon-Based Devices and ICs

Other Materials and Devices

Animation Viewer

An index ()f animati()ns f()r classro()m use bv instructoFs.

The Glossary

lntcractivc, hypcr-linkcd, illustrated gh_ssary fl)r students.

355
l)islocuti n uIld Plu tic t:l v,

x

Tensile Test

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Slip Planes & Directions in FCC

Shear --_ Extra

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Strain Around Scrcv, Dish),.:ation

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356
Stre_s Components

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357
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358
Pllase Diagrams

= Pb-Sn Cooling Cur_ c

Pb-Sn Microstructure

Cored Dendrites in Cu-Sn

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Pb-Sn Eutectic

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Phase Rule

CI.I-4(Y_ Zrl Braze

359
Magnotic Materials

Magnetization

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360
Magnetic Materials

Eddy Currents

i i

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Single Domain Particles

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Headphone Operation

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361
Electronic Materials

Semiconductor Materials

A04

Energy Band Formation

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Structure of Si, Ge

IP..._at_lldll¢ t

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Metals vs. Semiconductors

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A27

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362
Elcctn ]lic k l:tterial. 

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363
-Fhc tttt(_ri'alsImvc an intClFac¢tllzlt l()()k.s

likc a chalk board. Each is divided into

sccti(ms, and then into "pages," and the

lattcrarcacccsscd b\'. tabs at the top.

The navigation controls arc at the bottom,

and each page contains swlchronized

board items, animations, videos, photos,

drawings, derivations, etc. Here's one

showing the definition and use of the

lever rule.

The animation viewer can be used in the

classroom by an instructor to teach

concepts that involve motion and that

are difficult to visualize for beginning

students.

The interactive glossary is illustrated and

hyper-linked to other terms. It is primarily

for use bv students with the tutorials and

for review afterwards.

System Requirements

Windows ® CD-ROM

Windows 95 or NT 4.0 required

100MHz Pentium® or faster

16MB RAM

4X CD-ROM or faster

640 x 480 display, 256 colors

Windows compatible sounddevice

"In order to run properly, the included copy of Quicktime 3.0 must be

installed. On slower machines the contents of the CD (460MB) may

need to be copied to the hard drive for adequate performance

Macintosh ® CD-ROM

Mac"OS System 7.5 or higher

90MHz PowerPC'' or faster

9MB RAM free

4X CD-ROM or faster

640 x 480 display. 256 colors

__ QuickTime"

[SBN 0-9646598-2-4

364
ROOM TEMPERATURE CREEP OF SOLDER

Robert G. Stang

Department of Materials Science and Engineering

Box 352120

University of Washington

Seattle, Washington 98195-2120

Telephone: 206-543-2623

e-mail stang@u.washington.edu

365
Robert G. Stang

366
ROOM TEMPERATURE CREEP OF SOLDER

Robert G. Stang

Department of Materials Science and Engineering

Box 352120

University of Washington

Seattle WA, 98195-2120

ABSTRACT

Soft solder material, deformed under constant stress or load at room temperature, is

actually being deformed at a homologous temperature greater than 0.6 of the melting

temperature, where temperatures are expressed in degrees Kelvin. Deformation under

these conditions, at constant stress or load, is time dependent and is usually called creep.

The use of solder materials, in an undergraduate laboratory experiment, provides an

inexpensive, simple, safe and convenient method to introduce students to high

temperature creep behavior without the need for high temperature creep machines and the

associated hardware. The materials used, the data collected and the analysis of this data

from a series of creep experiments conducted at room temperature is discussed. The goal

is to introduce the subject of high temperature creep and present methods used to identify

the microscopic mechanisms controlling high temperature deformation.

367
ROOM TEMPERATURE CREEP OF SOLDER

Robert G. Stang

Department of Materials Science and Engineering

Box 352120

University of Washington

Seattle WA, 98195-2120

Keywords:

High Temperature Mechanical Behavior, Time Dependent Plasticity, Creep, Solder.

Prerequisite Knowledge:

The student should know or have general knowledge of the following:

1. How to calculate stress.

2. How to measure strain.

3. Know how to use binary phase or equilibrium diagrams.

Objective:

The objective of this experiment is to demonstrate high temperature behavior in metallic

materials without the need for sophisticated measuring equipment and furnaces, with the

associated safety problems involved with the use of high temperatures. The student will

learn how to plot creep curves, use these curves to obtain strain rate, fit strain rate vs

stress data to a power law equation and use the resulting parameters to identify the rate

controlling creep mechanism.

Equipment and Supplies:

1. Laboratory space in which the temperature is reasonably constant for the duration of

the experiment.

2. Thermometer.

3. Soft Solder material, Pb-Sn, or Bi-Sn.

4. 5 Minute Epoxy Cement.

5. Weights: lead or steel shot, scrap metal, etc.

6. Container to hold weight.

7. Balance to measure load on sample.

8. Measuring Device: Meter stick or cathetometer.

9. Timer: Clock or watch.

I 0. Micrometer: To measure sample diameter.

11. Computer with spread sheet program to analyze data obtained.

368
Introduction and Background:

The low eutectic temperatures for Bi-Sn (138.5 .C) and Pb-Sn(183 .C) and the availability

of these soft solder materials in local markets make them ideal for use in room

temperature creep experiments in undergraduate laboratories. These materials can often

be purchased in the coiled round solid form, free of flux, from local hardware or

electronic suppliers for use in plumbing applications (Bi-Sn) or electronic and stained

glass work (Pb-Sn). In creep studies it is common to express temperatures as

homologous temperatures in which test temperatures are expressed as a fraction of the

melting temperature, where all temperatures are expressed in degrees Kelvin. When this

is done eutectic Bi-Sn samples deformed at room temperature are undergoing

deformation at 0.71Tin and eutectic Pb-Sn samples deformed under the same conditions

are at 0.64Tin. Metallic materials deformed under these conditions exhibit time

dependent plasticity or creep. Virtually any soft solder material can be used to

demonstrate creep behavior at room temperature without the need for a furnace and the

associated equipment for strain measurement. Experiments have been conducted in this

laboratory using Pb-Sn solders of various compositions between 95% Pb-5%Sn to 40%

Pb-60% Sn and 50%Bi-50%Sn, where compositions are expressed in weight percent.

Strain measurements can be simply made using a ruler or meter stick or if more precision

is desired a cathetometer can be used.

The theoretical and experimental aspects of the study of time dependent plasticity can be

found in references (I-8). Time dependent plasticity studies begin by collecting a

number of creep or strain-time curves for a series of samples deformed under constant

load or constant stress conditions. Constant load tests are easier to conduct because the

initial load can be left on the sample for the duration of the test. During a constant stress

test the load must be changed as a function of strain because the cross sectional area of

the sample changes during the experiment making this type of test more difficult to

conduct. In either case, the resulting strain-time data is plotted in a linear plot creating a

creep curve. The strain rate, defined by the slope of the strain-time curve, given by

equation 1, goes through a minimum during the test. Note: The terms used in all

equations used in this paper are defined in table I.

=_A8 Equation 1

At

A schematic strain-time curve or creep curve for a well behaved annealed metallic

material is shown in figure 1(1). This creep curve can be divided into three stages, a

primary stage, the secondary or steady state stage and a tertiary stage as shown. The

strain-time behavior in the primary region is characterized by an initial elastic strain on

loading followed by a region in which the strain rate as measured by the slope of the

strain time curve is very high. The initial strain rate in the primary region is high because

the annealed material has a low dislocation content. As this annealed material work

hardens the strain rate decreases with time or strain until the secondary or steady state

region is reached. Strain rate behavior in the secondary or steady state region goes

through a minimum in a constant stress test or exhibits a constant minimum strain rate in

a constant stress test until the third or tertiary stage is reached. In the secondary region

369
the strain rate is a constant because a balance exists between work hardening and

recovery. The strain rate in the tertiary stage increases because void nucleation and

coalescence and necking reduce the cross sectional area of the sample and eventually the

strain rate increases locally until failure.

The primary creep region is strongly influenced by sample material and its prior thermomechanical history. This region can be difficult to model. The secondary region on the

other hand is well understood and several models resulting from theoretical and empirical

studies fit the data very well. These models generally yield equations for the steady state

strain rate which have the form suggested by Sherby and Burke (1) in equation 2 below

or by Bird, Mukherjee and Dorn (2) in equation 3 below.

Sherby-Burke (1)

Equation 2

Bird-Mukherjee-Dorn (2)

Equation 3

At constant temperature and structure both equations reduce to a simple power law

equation in stress as shown in equation 4.

_s = A(o')" Equation 4

The parameters in equation 4 can be evaluated by fitting experimental data to the

equation using a log-log plot of strain rate vs stress. These parameters after evaluation

can be used to extrapolate steady state strain rates, at the temperature under

consideration, for different stresses. The stress exponent, "n", in equation 4 can be used

to identify the microscopic mechanism controlling the creep process by a study of table

II, which lists stress exponents and the corresponding microscopic rate controlling creep

mechanism. These "n" values result from theoretical microscopic models which describe

the creep process. Detailed information concerning these models can be found in the

references.

370
Experimental Procedure:

A 10 inch length of 0.125 inch diameter solid uncored solder is uncoiled from the spool,

carefully straightened to avoid work hardening or damage and cut. The sample is gripped

by gluing each end in a separate 1 inch long round fight circular cylinder made from

1/2 inch diameter aluminum rod. One end or this aluminum rod is drilled and tapped to

accept a screw eye and the other end is drilled to clear the outside diameter of the solder.

Epoxy cement is used to form the joint. Approximately 1⁄2 inch is jammed into the

aluminum grip fixture filled with epoxy cement in the liquid state. It is important to

weigh the grip-screw eye assembly before gluing the solder to the grip. After the epoxy

cement has hardened, the assembly is transferred to a ring stand and supported vertically

under a minimum load, below the lowest stress used for up to a week, to straighten the

solder. The straightened sample is then ready for testing.

The sample gage length is established by marking each end of the sample, approximately

1⁄2 inch from the aluminum grip, with a black permanent marking pen used for metal

layout. The sample is loaded and timer started for the test. Sample elongation can be

determined by measuring the distance between these fiduciai marks using a ruler or a

cathetometer. Stress is determined and the creep curve plotted.

Results and Discussion:

The data presented here is for 50% Pb-50% Sn solder, although other solders could be

used for this experiment as discussed in the introduction. A typical creep curve is shown

in figure 2 for this solder. This material exhibits limited primary deformation because of

its thermomechanical history. After an abbreviated primary region the sample enters the

steady state region. The strain rate in the steady state region can be determined after the

sample fails or when one is certain the deformation process has reached the ternary creep

stage. A series of tests can be conducted at constant temperature, in this case room

temperature, at different stress levels and a log-log plot of strain rate vs stress

constructed. Such a plot for the 50-50 Pb-Sn solder used in this study is shown in figure

3. Curve fitting techniques coupled with data analysis packages which accompany most

spreadsheet software can be used to determine the stress exponent and the equation for

the best fit line which the experimental data describe. The slope of the log-log plot for

the set of data collected in this set of experiments is very close to 2. Study of table II

suggests that grain boundary sliding and accommodation is the rate controlling creep

process. The resulting data and equation can be used in exercises to extrapolate strain

rates for stresses outside the range of the test or to predict stress-strain rate behavior

within the range of stresses studied.

Comments:

This experiment provides a simple way to introduce the concepts used in high

temperature time dependent plasticity studies to undergraduate students. The lab group

gains experience in constructing creep curves, plotting data and fitting that data to a

power law expression.

371
Acknowledgments:

The author wishes to acknowledge the help ofHan Kim, Hao Pham, Corey Nianekeo,

Richard Chou, Linda Hoke, Mike Heit and Dan Williams, all former undergraduate

students in The Department of Materials Science and Engineering at The University of

Washington.

References:

1. Sherby, Oleg D. and Peter M. Burke, Mechanical Behavior of Crystalline Solids at

Elevated temperatures, Progress in Materials Science, Edited by Bruce Chalmers and

W. Hume-gothery, Pergamon Press, Volume 13, Number 7, p. 326. 1968.

2. Bird, James E., Amaiya K. Mukherjee, and John E. Dorn, Correlations Between

High-Temperature Creep Behavior and Structure, Proceedings of an International

Conference on The Quantitative Relation Between Properties and Microstructure,

Haifa Israel, Edited by D. G. Brandon and A. Rosen, p. 255, 1969.

3. Ashby, Michael F. and David R. H. Jones, Engineering Materials: An Introduction to

their Properties and Applications, pp. 157-190, Pergamon Press, New York, 1980.

4. Dieter, George E., Mechanical Metallurgy Third Edition, pp. 432-470, McGraw-Hill,

New YorlgNY, 1986.

5. Meyers, Mare A. and Krishan K. Chawla, Mechanical Behavior of Materials, pp. 540-

591, Prentice Hall, Upper Saddle River, NJ, 1999.

6. Courtney, Thomas H., Mechanical Behavior of Materials, pp263-324, McGraw-Hill,

New York, NY, 1990.

7. Poirier, Jean-Paul, Creep of Crystals: High-Temperature Deformation Processes in

Metals, Ceramics and Minerals, Cambridge University Press, Cambridge, 1985.

8. Wilshire, Brian and R. W. Evans, Introduction to Creep, Institute of Materials,

London, 1993.

372
Robert G. Stang

Associate Professor

Department of Materials Science and Engineering

University of Washington

Seattle, WA 98195-2120

B.S. 1961 Long Beach State College

M.S. 1965 UCLA

Ph.D. 1972 Stanford University

Engineering-ME. Option

Materials

Mat. Sci.& Engineering

After earning a Ph.D. in Materials Science and Engineering at Stanford University in

1972 Robert Stang accepted a temporary teaching posmon at Instituto Militar de

Engenharia in Rio de Janeiro, Brazil. In September 1972 he returned to Stanford

University as a research associate remaining until December 1973 when he accepted an

Assistant Professorship at the University of Washingtoa, Seattle. He received a Senior

Fulbright-Hayes Fellowship to teach and conduct research at Montanuniversitat in

Leoben, Austria in 1980-81. During the 1984 and 1985 academic years Professor Stang

served as a Program Director with National Science Foundation in Washington, D.C., in

the Division of Materials Research. He is a member of several professional societies and

has been active in ASM International at local and national levels.

Research Interests:

Professor Stang's interests lie in the area of mechanical behavior of materials. In

particular the relation between structure, processing and properties of materials. Much of

this work has focused on model systems for high temperature applications.

Current research programs focus on the study of creep in solder materials used in the

electronics industry. The creep work is attempting to develop techniques to speed the

acquisition to data which can be used to model creep behavior m and to study the effects

of hydrostatic pressure on the creep behavior of solder materials. Another study is

examining the effect of microstructure on porosity formation during plastic deformation

in two-phase alloy systems. In this study steels with various microstructures are studied.

373
Table I: Terms Used in Equations

= Strain

= Strain Rate

_s= Steady State Strain Rate

t = Time

A = A Material Constant

DSD= Self Diffusion Coefficient

G = Shear Modulus

o = Stress

n = A Constant which Depends on the Deformation Mechanism

k = Boltzmann's Constant

T = Temperature in Degrees Kelvin

b = Magnitude of the Burgers Vector

d = Grain Size

n

1

2

3

4.5

TABLE II

Stress Exponent-Microscopic Mechanism

Microscopic Mechanism

Stress Vacancy Diffusion Controlled Creep

Nabarro-Hen'ing Mechanism

Coble Mechansim

Grain Boundary Sliding and Accommodation

Diffusion Controlled Viscous Glide Dislocation

Motion

Diffusion Controlled Climb Motion of Dislocations

374
i

_m

r_

i03

tJJ

I.U

U

.14J

IZ:

t--

TERTIARY

STAGE "

E

INCREASES/

_ SECONDARY , /

- STAGE

= CONSTANTPRIMARY

ARE CONSTANT

TIME

Figure 1: Schematic strain-time or creep curve showing the primary, secondary and

tertiary stages of creep (]).

375
(too/too) u!P..q$

C_

0

e,O

0

0

0

c_

x--, o .__-_-_

e o_=.

_ _ •

_ _'_

O0 _o _._ _.

_ _--_°°

oo __ _._

"_

0

376
0.01 i i i i i = I I i i I I I I

I

liim

E

V

n_

L_

0,001

0.0001

0.00001

I

L.

100 1000 1O0O0

Stress (ib/in 2)

Figure 3: Log stress vs Log strain rate curve for the data collected for this study.

377

USE OF PIEZOELECTRIC CRYSTALS

FOR VOICE RECOGNITION

Harvey Abramowitz

Department of Engineering

Purdue University - Calumet

2200 169th Street

Hammond, Indiana 46323

Telephone: 219-989-2473

e-mail harveya@calumet.purdue.edu

379
l_ U_F

Harvey Abramowitz

380
Use of Piezoelectric Crystals for Voice Recognition

Harvey Abramowitz

Purdue University Calumet

Hammond, IN

Keywords:

Piezoelectric Effect, Electrostriction, Reverse Piezoelectric Effect, Voice Recognition

Prerequisite Knowledge:

The student

1. should be familiar with the concepts of the piezoelectric effect and electrostriction or

the reverse piezoelectric effect,

2. should be familiar with frequency generators and oscilloscopes,

3. should be familiar with PC's operating with MS Windows 95, and

4. should be familiar with a spectrum analysis software.

Objectives:

1. To demonstrate to students in a first materials science course the two modes in which

a piezoelectric crystal can be used, utilizing either the piezoelectric effect or the

electrostriction/reverse piezoelectric effect. 1"2

2. To show the potential for using a piezoelectric crystal for voice recognition.

Equipment and Supplies:

1. 1" Piezo Discs, such as those supplied by Edmund Scientific Company, Barrington,

NJ

2. Oscilloscope

3. Function Generator

4. BNC to Alligator Leads

5. 10x Oscilloscope Probe

6. Microphone

7.2 PC's with MS Windows 95, software for capturing oscilloscope images, and data

381
acquisition/spectrum analysis software

8. Workstation (optional)

Demonstration of Electrostriction/Reverse Piezoelectric Effect

Procedure

Connect the piezo disc to the Function Generator using the BNC to Alligator leads.

The disc should have two leads - the positive, red lead, soldered directly to the crystal

and the negative, black lead, attached to the brass plate to which the opposite side of

the crystal is attached. Adjust the frequency until an audible sound is heard. Find the

audible frequency range of the crystal. To amplify the sound, place the metal side of

the crystal on another piece of metal, sheet or plate.

Result

A frequency range of 800 Hz to 17 kHz should be obtained.

Demonstration of Piezoelectric Effect

Procedure

Connect the crystal to an oscilloscope. Set the sweep rate to 5 or 10 ms/div (X axis),

and the voltage scale to 50 or 100 mV/div (Y axis). Put the crystal on the table, crystal

side up, and press the crystal with a finger for an instant. Alternatively, press the

crystal by holding it between the thumb and forefinger, also for a short time.

Result

As the pressure on the crystal is increased, a higher voltage spike is generated. If the

pressure is too high, the spike will go off screen. In such a case, change the voltage

scale as needed.

Use of Piezoelectric Crystals for Voice Recognition

Oscilloscope Patterns

Procedure

Set the sweep rate to 5 ms/div and the voltage range to 100 mV/div. Place the crystal

on the larynx and hold one particular sound for a few seconds. A distinctive pattern for

382
each individual should be seen. Suggested sounds to begin this exercise are a, b, la,

da, and ma. Try the same sounds with both a male and female student.

Results

Figures 1-4 show the results for two speakers - malel and femalel - continuously

saying the letters a and b. As expected, the female voice has a higher frequency and

the pattern repeats approximately every 5 ms for the letter a and 4 ms for b. The

pattern of the male voice repeats every 9 ms for a and b.

These plots indicate the possibility of using the crystal to identify individuals, and

perhaps establish a voice recognition system based on a single crystal. Usually, such a

system relies on a comparison of a full frequency spectrum analysis of the voice in

question with a filed spectral analysis of that individual. In most of these systems, a

microphone is used. Also, a normal speech pattern is employed, where letters, words

and sentences are spoken at a normal rate, instead of holding a single continuous

sound. Therefore, the next step of the demonstration is to see if a microphone can be

replaced by the crystal.

Comparison of Piezoelectric Crystal with Microphone

Time Domain Plots

Procedure

Connect the crystal to the audio input of one PC and a mic to the audio input of another

PC. Open the Sound Recorder software available in MS Windows 95 and record

predetermined sounds on each PC by pressing the record buttons of both PC's at the

same time. Stop the recording in a similar fashion. The start to finish time of

recording should thus be approximately the same. By recording simultaneously, the

inputs to the transducers are from the same speaker. The wave files produced are

imported into analysis software, such as MATLAB. Time domain plots can thereby be

obtained.

Results

Typical time domain plots are shown in Figs.5-8. These plots were made by two

speakers (male2 and femalel) pronouncing the letters a, b, and c into the mic and

383
crystal at the same time. The graphs plot voltage versus the sample number or index.

Sampling takes place every 45/zs. Total sampling time ranges from 4-5 seconds.

The major difference between the plots for the mic (Figs.5 and 7) and the crystal

(Figs.6 and 8) is that the crystal plots show saturation. This is due to the fact that the

piezoelectric crystal disc was placed near the throat cavity/voicebox and breathing

causes vibrations in addition to those produced by speaking. In terms of signal to noise

ratios, the ratio for the crystal is much higher than that for the mic. The reason for this

difference is that the mic picks up ambient noise from the environment, while the

crystal signal is independent of the environment and is a function of the speaker's throat

cavity/voicebox movements. How high the crystal signal to noise ratio can go is still

unknown and will be investigated.

Comparison of Vocal Tract Spectra

Procedure

Find the vocal tract spectra by manipulation of the time domain data via fourier

transforms. This can be accomplished, for example, by using the X waves package

from Entropic Research Lab, Inc. on a Sun workstation. A comparison of the formant

(key) frequencies will give an idea as to whether or not the crystal can replace the mic.

Resul_

The vocal tract spectra plots comparing the mic with the crystal for the 'a' vowel

sound spoken by male speaker 2 are shown in Figs.9 and 10. The first four formant

(key) frequencies are listed in Table 1.

The comparison listed in Table 1 indicates that the spectra are similar, although not

exact. It appears that the possibility exists for using the crystal for voice recognition.

Further work is underway to refine this usage for very inexpensive crystals.

Conclusions

1. The electrostriction and piezoelectric effects can be demonstrated using crystal discs.

2. The possibility of using these discs as the transducer for a voice recognition system

has also been shown.

384
Acknowledgements

The author would like to thank Prof. G. Gopolau, Jack Woods, and Leticia Soto Jones

for their help.

References

1. Askeland, D.R., The Science and Engineering of Materials, 3rd ed.,

PWS Publishing Company, Boston, MA, 1994, pp.636-638.

2. Shackelford, J.F., Introduction to Materials Science for Engineers,

Prentice Hall, Inc., 4th ed., Upper Saddle River, NJ, 1996, pp.454-455.

385
Table 1

Formant (F) Frequencies for Male2 Speaker, 'a' Vowel Sound,

Using Mic and Piezoelectric Crystal

Transducer

Mic

Piezoelectric Crystal

Formant Frequencies(Hz)

F1 F2 F3

394 1856 2306

366 1462 2306

F4

3150

2900

386
SweepRate(Sms/cliv)

Figure 1- Oscilloscope Pattern for Malel Speaker, 'a' Sound

.,.,i

8

v

N

O

C

,,l,l,,,,I,tRl[if_,l,,,,[&llll,,t,l,,*,[.It_|,,,_

Sweep Rate (5ms/div)

Figure 2: Oscilloscope Pattern for Malel Speaker, 'b' Sound

387
8

0

....i.,..l...'i',..l''''i''''l''''l''''l'''"i'''' I

o

I

Sweep Rate (5ms/div)

Figure 3: Oscilloscope Pattern for Female l Speaker, 'a' Sound

g

a_

==-i

0

i

Sweep Rate (5ms/div)

Figure 4: Oscilloscope Pattern for FemaleI Speaker, 'b' Sound

388
,.O.2

-0.4

-0.6

o-'I

!

I

O.2-

t

X 104

Sample Number

-0.8

Figure 5: Time Domain Plot for Male2 Speaker, 'a','b', and 'c' Sounds, Mic

>.

Tr

I

0.8;

J

o.s'--

0,4'-

o.z)

ql.2

43_

i

"0"8b

.11

0

!:j

Sample Number

Figure 6: Time Domain Plot for Male2 Speaker, 'a','b', and 'c' Sounds, Crystal

389
-0.8

x 104.

Sample Number

Figure 7: Time Domain Plot for Femalel Speaker, 'a', 'b', and 'c' Sounds, Mic

>

3 _

Sample Number

Figure 8: Time Domain Plot for Femalel Speaker, 'a', 'b', and 'c' Sounds, Crystal

390
100

90

80

70

60

50

40

30

20

10

O.0Hz $5.9di3

2000 4000 6000 8000 10000

Frequency (I-tz)

Figure 9: Vocal Tract Spectrum for Male2 Speaker, 'a' Sound from Figure 5, Mic

60

5O

40

30

20

2000 4000 6000 8000 10000

Frequency (Hz)

Figure I0: Vocal Tract Spectrum for Male2 Speaker, 'a' Sound from Figure 6, Crystal

391
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 a Visiting Professor at the University

of Missouri, Rolla. He is currently an Associate Professor of

Mechanical Engineering and is responsible for the materials

courses. Major areas of research are the treatment of waste

streams for metal recovery, and the cryogenic treatment of

steels.

392
CONCURRENT ENGINEERING: EXPERIMENT 1

PRODUCT ANALYSIS AND PROTOTYPING

James B. Higley

Yulian B. Kin

Bernard W. Parsons II

and

Christopher M. Prochnow

Purdue University Calumet

METS Department

Hammond, Indiana 46323

Telephone 219-989-2584

e-mail higley@calumet.purdue.edu

393

National Scien .c_"Foundation

Concurrent Engineering: Experiment 1

Product Analysis and Prototyping

James B, Higley

Yulian B. Kin

Bernard W. Parsons II

Christopher M. Prochnow

Purdue University Calumet

Hammond, IN 46323

Key Words: finite element analysis (FEA), laminated object manufacture (LOM), rapid

prototyping (RP)

Prerequisite Knowledge: Knowledge of three dimensional solid modeling software and

basic strength of materials are required to complete this experiment.

Objective: This experiment explores two areas of product engineering: finite element

analysis and rapid prototyping.

Equipment:

1. Personal computer workstation with Mechanical Desktop TM, Design Space TM,

Silverscreen TM, and JP5 TM software.

2. JP5 rapid prototyping system with Roland PNC-910 sign maker plotter, cutting board,

registration board, registration pins, pressing board, spray adhesive, X-Acto Knife,

prototype material, masking tape, and Elmer's glue.

Introduction

The technical portion of a product's life cycle includes design, analysis, prototyping,

testing, manufacture, and reclamation. When all these activities are done in parallel and

combined with non-technical activities such as marketing, the whole process is frequently

referred to as concurrent engineering (CE). The use of computerized three dimensional

solid modeling techniques has made great advances in CE possible. The key to CE is a

single, solid model database for each part used in a product. Engineers use this file,

created during the design phase, to analyze the part, build prototypes, and manufacture

395
thepart. Changesarethenquickly madeavailableto all peopleworkingonthepart

becauseeveryoneworksoff the samedatabase.1

Along with three-dimensionalsolidmodeling,otherpowerfultoolsareavailableto speed

thedesign,analysis,andprototypeportionof aproduct'slife cycle.Thesetools include

finite elementanalysisto checkstresses,rapidprototypingto quicklybuildpart models,

andgraphicalcomputernumericalcontrolprogramming.Thefirst two of thesetoolswill

beexaminedin this experiment;thethird is coveredin thenextexperiment.

Finite elementanalysis(FEA) is anold techni2queusingnumericalapproximationsto

estimatestressanddeformationof solidparts. Thisis donebybreakingthepartdown

into many smallvolumes,analyzingeachvolumeindividually, andthensummingthem

togetherfor thefinal result.Like mostnumericalapproximations,powerfulcomputersare

necessaryfor effectiveuse.Now, FEAtoolsareavailablewhichcanperformcomplicated

analysisonthe3-D datathedesignercreates.Part 1of thisexperimentillustratesthis.

Theterm rapidprototyping(RP)is arelativelynew expressionforthegenerationof

three-dimensionalmodelsmanufactureddirectly from thethreedimensionalsolidmodel

without the needfor machiningor tooling. 3 This process, which was first introduced by

NASA in 1988, adds material layer by layer until the desired shape is achieved. A

number of different processes and materials may be used for RP, but all follow roughly

the same steps. RP machines operate by slicing the 3-D CAD data into thin slices

(roughly the thickness of paper) and then creating the thin slices from solid material and

joining the slices together. The result is a reasonably accurate physical part that can be

handled and, depending on the material, actually used.

In the second part of this experiment, you will use a method called Laminate Object

Manufacture; perhaps the simplest RP method available. The slicing software drives an

X-Y sign cutter which cuts out pieces of paper to the desired shape. The paper slices are

then manually glued together to create the finished part. This process has the advantages

of simplicity and low cost, but errors in assembly are possible.

Procedure Part 1 - Finite Element Analysis

Design Space TM is a powerful software program that computes many common

engineering calculations very quickly and very precise. Follow the steps outlined below

to graphically analyze a sample part from its solid model.

STEP 1:

1.

STEP 2:

1.

Drawing an AutoCad TM drawing.

Before analyzing a part, you must create a three dimensional solid model of

the part using sot_are like Mechanical Desktop TM. For this experiment, a

model has already been created for you to use.

Opening Design Space.

In Window's, click the Mechanical Desktop icon. Design Space automatically

loads with Mechanical Desktop.

396
STEP 3:

1.

Opening and preparing an AutoCad drawing.

The sample file, Experiment#1.dwg, is on the network. Choose the open icon

and follow the links to Find File, Network, Netware Services, Intranetware

Servers, Lab, Dept, L_mets, MET305. Locate the file in this directory, click

on it, and click OK. The part looks like Figure 1 below. The part looks like

Figure 1 below. Note, once this link has been made, Windows will assign a

drive letter to the final directory. Hence, once the drive letter has been

assigned, the directory may be referenced using the letter instead of the long

link. Once the user logs offor reboots the computers, the link will have to be

performed again.

STEP 4:

1.

STEP 5:

1.

Figure 1. Sample Part

2. Highlight the isometric view of the part, top right quadrant, and type '1' and

press ENTER. This will zoom in to show only the isometric view.

Entering Design Space.

Click on Design Space-Stress Wizard. This will take you to a wizard.

Wizards are used to make complicated tasks much easier. This is done by

breaking the tasks down to simpler steps, arid pressing Next as each task is

completed.

Working with the Wizard.

The introduction page of the wizard will give you an idea of what will be

happening. Read this screen and press NEXT when ready to begin.

2. Verify that the Potential Stress Failure Units are in 'U.S. Customary (in,

Ibm, psi, s)'. Also, check to see that 'Inches' are marked in the box which

reads 'What units is your drawing in?' Click on NEXT when completed.

3. Be sure the 'What material is the part made of?.' is set to STRUCTURAL

STEEL and DUCTILE is set in the 'How does this material behave' box.

Click NEXT when this task is complete. Other materials are available, and the

list can be customized with additional materials.

397
4. A box will appear on the screen reading 'You must now pick the part box!'

Click on OK and the screen will switch to the familiar Mechanical Desktop.

Pick the part as the prototype to be worked with.

5. The program will revert back to the Design Space screen where the wizard

will be reading LOADING and SUPPORT. You will now want to click onto

the ADD... button in the LOADING section to add a simple loading to the

part.

6. Click on the FORCE tab and be sure the 'Full Surface' is highlighted. Click

on NEW to place the location of the loading. Click on the face where you

will want to place the load. This face will become highlighted with a dashedline. You may choose N (Next) or ENTER to accept.

7. After accepting the face, you will need to enter the loading value using the

World UCS as the guide. Remember to keep in mind if you are representing a

positive force or a negative force according to the UCS. After entering the

value of the force (in pounds), click on CLOSE. You will return to the

LOADING and SUPPORT screen again.

8. Continue to add loadings as is necessary for the application of the prototype.

If a mistake is made, click on the loading line and DELETE to remove the

loading from the part.

9. When all loadings are entered and complete, there is a need for at least one

support hold or guide for the part. To do this, click on ADD... in the

SUPPORT section.

10. Again, select the surface that is the actual support or guide which the part will

follow. Press N (Next) if you need to shuffle through the faces and ENTER

to accept. However, with support, no value is needed.

11. Continue to add support to the part if it is required in your application.

Choose CLOSE when the task is complete.

12. You will return to the wizard which will give you the status and press NEXT.

Read the next page to the wizard and and click on FINISH to finally complete

the process. Design Space will now compute the stresses, deformation, and

factor of safety using the applied forces. This may take a few moments to

complete.

13. Upon completion, Design Space will post the Minimum and Maximum Stress,

and the Minimum and Maximum Deformation. Factor of Safety is found by

fight-clicking on the MAX EQUIVALENT SAFETY TOOL and then

clicking on RUN TOOL. By clicking on the CONCLUSIONS tab, the

Factor of Safety will be displayed. Click on close to escape.

STEP 6:

1.

Data pictorials.

To pictorially represent the stresses, right click on the EQUIVALENT

STRESS line and click on DRAW. The Mechanical Desktop window will

398
.

STEP 7:

1.

STEP 8:

1.

reappear and you will be prompted to pick a point to insert the drawing.

a point which is well away from the rest of the drawing.

Repeat the same procedure if you desire to display a picture of the

deformation.

Pick

View the pictures.

In order to view the pictures, you need to return to Mechanical Desktop. To

do this, click on the minimize button in the top right comer of the screen.

This will automatically take you to Mechanical Desktop.

Plotting pictures.

These pictures may be plotted as a regular AutoCad file is plotted or you can

CUT and PASTE them into a word processing or paint brush application.

2. Close out Design Space once complete.

Procedure Part 2 - Rapid Prototyping

This Laminated Object Manufacture (LOM) machine uses SilverScreen / JP-5 System in

combination with the Roland PNC-910 plotter. Follow the steps listed below to complete

a prototype of the sample part.

When completing a LOM prototype, there are eight (8) simple steps. They include:

1. Draw a 3-D solid model.

2. Convert the model to a .STL file.

3. Open the .STL file.

4. Orientate the .STL file.

5. Slice the .STL file.

6. Load plotter with material.

7. Plot the .STL file.

8. Assemble the prototype.

KEYPOINT: The key thing to remember when orienting and sBcing the object is that

the slice acts like a knife cutting along the x-axis and works its way up the y-axis. In

addition, the final assembly of a prototype is much easier when the base (larger end) is

on the upper region of the part. This will reduce much of the difficulty when it comes

time to put the prototype together.

STEP 1:

1.

STEP 2:

1.

Drawing an AutoCad drawing.

Open file Experiment#1.dwg following the same steps from Part 1, Step 3

above. Note, if you already made the link in this login session, you do not

have to relink the directory. Choose open and find the drive Windows

assigned to the MET305 directory.

Converting an AutoCad fde (.dwg) to .stl.

In Mechanical Desktop, verify part is in the positive x, y, and z octant. To do

this, check all extremes of the part and keep close attention to the coordinates

located at the bottom of the screen. In order to complete this step, all

399
.

.

.

STEP 3:

1.

coordinates must be positive. Change UCS (UU) if needed in different views

to verify. If part needs to be moved, use the MOVE command.

Type EXPLODE, click on the part, and press ENTER. This changes the part

from a Mechanical Desktop parametric part to a simple AutoCAD solid. This

operation destroys the ability to edit the part, so do not save the file after

performing this operation.

Type in STLOUT and press ENTER. Click on the part and press ENTER.

Type in Experiment#1 when prompted and press OK. Enter "N" when

prompted to create a binary sfl file. Save the file in your directory, in the

temporary directory, or on a floppy disk. This is the sliced file required as

input to the RP system.

Close Mechanical Desktop.

Opening an .STL file.

To start SilverScreen / JP-5 System, double click the shortcut icon on the

Window's desktop.

2. Click on TOOLS - EXECUTE and pick "sys5.ex" and click

on OK button. Moment's later, JP-5 System will load. Note the background

will turn to a white screen and JP System 5 will read at the top left comer of

the screen.

3. Click on FILE-OPEN STL FILE and change Look in Box to to where you

saved the .stl file.

4. Choose "Experiment #1.STL" file and click the OPEN button. This may

take a few moments for the file to load.

4OO
,

STEP 4:

1.

STEP 5:

1.

The file viewed in Mechanical Desktop will appear as a white solid model in

the JP-5 System.

Orientate the .STL f'fle.

Click on the SETUP-ROTATE and

choose the x-axis in the "Rotate about"

box. Next, enter 90 in the box for which

to rotate the part. Click on OK when

complete. JP System 5 will then inform

you of the new dimensions and click OK

to continue. Refer to the above

KEYPOINT for clarification on why and

when rotation is necessary.

Slicing an .STL file.

Click on SETUP-SLICE and be sure that the Slice Extent is set to Full and

the Material chosen is Standard. Click on OK to continue. Click on the

YES button when you are prompted to continue. This process of slicing the

object may take several moments to complete depending on the speed of your

computer. When slicing is complete, object will turn brown in color and Slice

Current Model will be displayed in the lower right comer of the screen.

. You may wish to view the sheets before plotting. To do this, click on

VIEW-SI_EETS and you may need to wait for a few moments for the

preview of the sheets will be displayed. You then may scroll through the

401
STEP6:

1.

.

pages to be printed by pressing the arrow keys located on he left side of the

screen. This step is not completely necessary but convenient to identify

what will be plotted.

Loading the plotter.

This system utilizes the Roland PNC-910 Sign Maker to cut out patterns for

assembly. Locate the lever on left side of machine. This lever is used to

lower and raise the rollers on the machine. When the rollers are in the up

position, they are open and ready to insert material. When lowered, the

material is secure.

Turn power switch on left side to ON. Notice the cutter head moves to right

side.

BE CAREFUL NOT TO HAVE YOUR HANDS OR OTHER OBJECTS

NEAR THE TOOL CARRIAGE OF THE PLOTTER TO AVOID

.

.

DAMAGE OR INJURY.

Press the SETUP button until the cutting head moves to the right side of the

machine. Push roller levers to the up position. You are now ready to load

material.

Slip material under rollers and push through until the front edge of the

material lines up with the front of the blue cutting surface using pencil mark

as guide for left edge of material. The first two sheets (MASK and Sheet #1)

are loaded with the off-white side of the material facing upward. The

following sheets are placed with the bright white side of the material facing

upward as shown in Figure 2.

0

0

0

0

iO

0

0

.

Figure 2. Sheet Placement on Plotter.*

Once aligned, push lever down to lock the material into position. Press

SETUP button once again keeping hands and objects away from the cutter

head. Once head reaches left side of machine, press ORIGIN SET button.

The machine is now prepared to cut material for assembly.

402
. To remove material in the future, press SETUP button, push lever to up

position, remove material, insert new material align, push lever to down

position, press SETUP button again. You are now ready to cut another sheet.

STEP 7:

1.

.

STEP 8:

1.

.

.

Plotting an .STL f'de.

Click on PLOT-CUT SHEETS and click on the

"ALL" button at the top left comer of the screen

and choose OK. This will print all sheets along

with a MASK. Change the cutting data, if needed,

to read as the dialogue box appears to the fight:

Remove material plotted upon and re-load the

material in the correct fashion as indicated in

Step #20. Click on OK to plot the next page.

Repeat this step until all pages are plotted.

Assembling the prototype.

Insert registration posts into registration holes located in the near middle of

the board. These holes are approximately 8.0 inches apart from each other.

On all sheets, be sure all the registration holes are completely cut out and the

material is removed from the holes.

Remove any non-sliced interior void areas from Sheet #1 as shown in Figure

3.

c

.

Figure 3. Removal of Non-sliced Areas.*

Layout Sheet #1 onto the major registration posts with the circular hole over

the left pin and the slot over the right.

403
. Tape this first sheet down to registration board as shown in Figure 4.

Figure 4. Paper orientation on registration board.*

6. Using the cutting board and the X-acto knife, cut out the partially cut openings

of the sheet labeled MASK.

7. Cover Sheet #1 with the MASK with round hole again on left side.

8. Spray adhesive evenly through openings on MASK. Adhesive will only be

sprayed onto Sheet #1 as shown in Figure 5.

Figure 5. Spray adhesive through mask.*

9. Remove MASK when the spraying task is complete.

10. Remove any non-sliced interior and exterior voided areas from Sheet #2 and

Sheet #3 only leaving only the cut-out design.

11. Place Sheet #2 with the side with the enclosures removed facing down onto

Sheet #1. The circular hole still on left pin. Be careful because Sheet #1 will

be very tacky from the spray adhesive.

404
12. Using the application board, press the material firmly being careful not to shift

the material being sandwiched as shown in Figure 6.

Figure 6. Joining Sheets.*

13. Once the pressing is complete, remove the support base (backing of the

sticker) leaving the cutout portion of the material behind as shown in Figure 7.

Be very cautious when removing material to see that the cutout did actually

fasten to the previous sheet. Attempt to remove backing at a 90 ° angle when

possible.

Figure 7. Peel OffUnused Paper.*

14. Repeat Steps 33- 35 for all sheets except for the final sheet.

15. Place the final sheet onto the sandwich of sheets and press.

16. Again, remove the backing from all sections with exception to the section

marked as A-A, top lett section.

17. Cut section A-A out using the x-acto knife.

18. Remove the sandwiched set of sheets from the board. Reposition the

registration pins into the holes approximately 4 1⁄2 inches apart.

405
19. With a pencil or pen, mark each section of the last sheet with an identifier

starting in the upper left hand comer, as follows:

A B

C D

E F

G H

I J

K L

20.

21.

Cut all sections out at the horizontal and vertical separator lines. Once cut,

turn these sections over starting with A and place onto the minor registration

holes. Section A should contain the cutout for the registration holes.

Press the stack and remove the support base backing and repeat placing the

next section onto the registration posts and pressing firmly. Repeat until all

sheets have been attached. Remove the entire assembly from the minor

registration posts and bottom support base. Care should be taken since stick

adhesive will be present on the outside of the prototype. Coat the assembly

with Elmer's Glue. Give the assembly a second coat once the first is

completely dried.

Cutter and Plotter Reference Settings

Left roller distance from left side of machine = 2 inches

Right roller distance from left side of machine = 10 inches

Plotter width = 10 inches

Plotter length = 7.50 inches

Rotation - Off (Portrait setting)

Major Registration = 8 inches

Minor Registration = 4.5 inches

Project Report

Search the interact to find another method of rapid prototyping and search the library for

a third. Write a short report comparing the LOM method with the two methods you

found.

406
References

1. Chipley, K.; Viswanathan, S.; Cooper, RH.: Concurrent Engineering and Rapid

Prototyping for Die Casting. Die Casting Engineer, vol. 40, no. 2, Mar-Apr, 1996.

2. Roensch & Associates, http://eee.execpc.com/!sroensch/fea.html.

3. Studt, Tim. Rapid Prototyping Key to Fast Development. R&D Magazine, May,

1994, pp. 55-56.

Credits

* Drawings marked with an asterisk (*) used with permission of Schroff Development

Corporation.

407

CONCURRENT ENGINEERING: EXPERIMENT 2

DESIGN THROUGH PROTOTYPING

James B. Higley

Yulian B. Kin

Bernard W. Parsons II

and

Christopher M. Prochnow

Purdue University Calumet

METS Department

Hammond, Indiana 46323

Telephone 219-989-2584

e-mail higley@calumet.purdue.edu

409

National Sc_n_ Foundation

Ol_mlonm,xlmmmll m,m:_oee of "_4*ram*or*

and r*o'_ _*_mnl'v' _ ot _ _ioqn

Concurrent Engineering: Experiment 2

Design Through Prototyping

James B, Higley

Yulian B. Kin

Bernard W. Parsons II

Christopher M. Prochnow

Purdue University Calumet

Hammond, IN 46323

Key Words: finite element analysis (FEA), multi-jet modeling (MJM), rapid prototyping

(RP), computer numerical control (CNC) machining

Prerequisite Knowledge: Knowledge of three dimensional solid modeling software and

basic strength of materials are required to complete this experiment. Completion of

Experiment 1 in this series is also required.

Objective: This experiment explores the design, analysis, prototype, and manufacture of

a simple part.

Equipment:

1. Personal computer workstation with Mechanical Desktop TM, Design Space TM,

Allegro TM, and EdgeCam TM software.

2. Actua 2100 rapid prototyping machine.

3. Bridgeport Series I CNC milling machine with fixtures, end mill holder, and 1⁄2"

diameter two flute endmill.

Introduction

The key element of Concurrent Engineering is the three dimensional solid model drawn

in a CAD system. This central item is used, in varying formats, as inputs to FEA

software, Rapid Prototyping (RP) machines, and Computer Numerical Control (CNC)

machines among others.

In this experiment, you will create a part with a 3D solid modeler, analyze the part with a

graphical FEA package, prototype the part with an MJM RP machine, write the CNC

411
program, and machine the real part. These are all the steps needed to successfully design

and build a useful part.

Problem Statement

Design a connective member from aluminum alloy 606 l-T6. The blank measures a

nominal 2" by 4". The member will experience tensile forces totaling 13.75 kips from a

pair of pins 0.6875" in diameter spaced 2.2500" apart. The part will be machined with a

1⁄2" diameter endmill, so all internal features must accommodate the cutter. Internal

features will be machined first, and then the part will be clamped with 1.5" diameter

washers over the pins to machine the exterior. Be sure the part clears these washers.

la.7s .

,/2x2x4,, 6061 T6 A, _ 7...._k / I _'_

/ ' /

/ _ 2.2500 /?\

0.8750 - _/

Figure 1. Layout

Procedure Part 1 - Design and Analysis

1. Load Mechanical Desktop. EdgeCAM and Design Space both load with

Mechanical desktop. " '.

2. Draw your fully constrained part and orient it as shown in Figure 2 using the

left front isometric view. Be sure your XY axes point as shown in Figure 2,

and move the origin (use the UCS command) so the part lies entirely in the

positive XYZ quadrant.

412
_fe_

Figure 2. Layout

. Use DesignSpace to verify and improve your design. (Specific instructions

are contained in laboratory experiment #1.) The part should be as light as

possible while still maintaining an acceptable stress level in the chosen

material.

Procedure Part 2 - Prototyping

°

.

*

From the browser, make a copy of your part. Explode the copy and then use

STLOUT to create a .STL file from the exploded copy.

From START menu on your desktop select PROGRAMS and ALLEGRO,

and the Allegro dialog box appears.

Select Actua_l in the Allegro window by double clicking on it.

413
4. The Print Manager dialog box will then appear.

5. To submit a job, click on submit icon, and the Submit dialog box appears. As

.

7.

.

9.

10.

files are selected, they will appear in the Om'ently Selected Files window.

Click the Select Files button to see the Select Files dialog box.

Navigate normally to locate your .STL file. Click on Open when located to

place the file in the Currently selected Files area of the Submit dialog box.

Verify Options are correct and click Submit.

The Print Manager dialog box now contains submitted request and will show

job status until finished at which time a pop-up message will direct the

operator to remove the finished model.

After the MJM modeler creates the part model, clean up the model and

examine it for fit and function. If any changes are needed, go back to Part 1,

Step 1, and make the changes.

Procedure Part 3 - Manufacturing

° Once satisfied with the part, load the drawing in Mechanical Desktop, orient

the part as shown in Figure 2 being sure the XY axes are oriented as shown.

Then, click on the EdgeCAM icon as shown in the upper right comer of

Figure 2. This links EdgeCAM with Mechanical Desktop allowing you to

write CNC machining instructions from within Mechanical Desktop. Any

changes made to the model automatically change the CNC code.

414
EdgeCAMbringsupits Operationstoolbarasshownbelow. Dock it in an

openborderarea.

. Click on the Identify Mill Feature icon, the left hand one in the Operations

tool bar. When choosing the first manufacturing operation, we must supply

some information about the machine tool, so EdgeCAM presents the

following dialog box which is not part of Identify Mill Feature. You'll only

need to fill it out once as shown below:

.

Pick O for origin and specify the origin as the center of the top left hole. Use

the CENter OSNAP to choose it.

We must now define the outer profile. Fill out the next dialog box as shown

below:

415
.

Pick an edge on the upper profile, accept it, and press enter until the command

prompt appears again. The edges on the upper surface are now green

signifying that they have been defined.

Click on the Identify Milling Feature icon, and fill out the dialog box as

shown below:

.

Choose any internal features you may have such as holes or slots and accept

the default heights.

Select the Pocket Operation from the Operations toolbar and choose the left

hand hole. You may have to use a window to pick the hole. Click each of the

three tabs in turn and fill them out as shown below:

416
417
.

.

8.

.

10.

11.

Repeat Step 5 for the same hole and change the Offset to 0 and the Cut

Increment to 0.3 in the Finishing dialog box.

Repeat Steps 5 and 6 for the remaining hole.

Click on the EdgeCAM icon _'. EdgeCAM will now load.

Click on the Rapid To Toolchange icon. _ _?_

Click on the Mechanical Desktop icon I to return the Mechanical Desktop.

Click on the Profile Operation from the Operations toolbar. Fill out both

dialog boxes as shown below:

418
12. Repeat Step 11 with the same General data, but change the Finishing dialog

box as shown below:

419
13.

14.

We can now simulate the machining operations to look for errors. Click on the

Define Stock icon _. Choose box and -0.5 for the depth. Type in -0.875,-1

for the first comer and 3.125,1 for the second comer.

Click on the EdgeCAM Verify icon [_. This loads a separate program to

simulate machining. Once the program loads, click once to remove the title,

and the screen appears like this:

420
f. It, _'_'_'n_ "_ " _"

15.

16.

17.

Now, click on the Simulate Mode icon :_and then the start icon _. Watch

for gouges in your part. If the part looks as you intend, close out of Verify

which then returns you to Mechanical Desktop.

The program is now complete, but the instructions must be converted to a

language the CNC machine can understand. Click on the Generate CNC Code

icon _ and place the file in your directory. Save all files and leave

Mechanical Desktop.

Change the program file's extension fi:om .NC to .AGC and copy the file onto

a floppy disk. Your instructor will help you Set up and run the milling

machine.

Project Report

Prepare a professional looking folder with an othographic drawing of your part, a printout

of the FEA analysis including stress gradient and distortion profile, and a printout of the

CNC code to machine your part. Briefly explain your rational for the shape of your part.

Prepare a short presentation to share your design with the class.

421

CONCURRENT ENGINEERING: EXPERIMENT 3

DESIGN PROJECT

James B. Higley

Yulian B. Kin

Bernard W. Parsons II

and

Christopher M. Prochnow

Purdue University Calumet

METS Department

Hammond, Indiana 46323

Telephone 219-989-2584

e-mail higley@calumet.purdue.edu

423

::__:_!!i_. _ .!i!._i::-_: i :

Natw, uai::! ,.......... _::;i ....

Concurrent Engineering: Experiment 3

Design Project

James B. Higley

Yutian B. Kin

Bernard W. Parsons II

Christopher M. Prochnow

Purdue University Calumet

Hammond, IN 46323

Key Words: finite element analysis (FEA), multi-jet modeling (MJM), rapid prototyping

(RP)

Prerequisite Knowledge: Knowledge of three dimensional solid modeling sot_ware and

basic strength of materials are required to complete this experiment. Completion of the

first two experiments in this series is also required.

Objective: This experiment presents a comprehensive project that covers design,

analysis, prototype, and reclamation of a product.

Equipment:

1. Personal computer workstation with Mechanical Desktop TM, Design Space TM, and

Allegro TM software.

2. Actua TM 2100 rapid prototyping machine.

Problem Statement

Design a tool to remove two gears on an industrial conveyor system, Figure 1.

425
Figure 1. Gear System

This conveyor uses a ten (10) horsepower, 1800 RPM motor with a spur gear system.

Both gears, as shown in Figure 1, are made of a case hardened nickel-molybdenum 4620

steel with a surface hardness of approximately Rc 60 and a core hardness of

approximately 200 Hb. One gear has 30 teeth with a diametric pitch of 5.0 inches and an

inner diameter of 0.75 inches. The second gear has 21 teeth with 1.5 inch diametric pitch

and an inner diameter of 0.50 inch. The gears are press fit on their shafts and may take as

much as 3 000 pounds of force to remove.

Design and assemble your tool using Mechanical Desktop. Analyze each part with

Design Space. A factor of safety is not given because Design Space will be used to

compute this for your proposed tool. Finally, prototype the tool with the Actua 2100

MJM modeler. When designing your tool, consider how to reclaim materials once the

tool wears out or breaks.

Due to material costs, only two (2) prototypes of the proposed tool will be allowed on the

Actua 2100. In addition, only one (1) plate will be allowed for plotting of each

prototype, so orientation of the multiple parts of this tool is critical.

With regards to the hardware, you are instructed to use nominal size bolts, nuts, and

washers. Such sizes include diameters in 1/16" increments between 1⁄4" and 1A" and

lengths in 1A" increments between 1/4" to 2 inches.

Project Report

Prepare a professional looking folder with an abstract of the project, a discussion of your

design, a reclamation plan, a complete set of drawings with a bill of materials, the Design

Space analysis, and disks with copies of all files. Prepare a short presentation with visual

aids including your two assembled prototypes.

426
Biographies

James B. Higley holds the rank of Professor of Manufacturing Engineering Technology.

He is responsible for coordinating the Manufacturing Engineering Technology (MFET)

program, as well as advising all MFET students. He holds a Bachelor of Science Degree

in Mechanical Engineering from Purdue University Calumet and a Master of Science

Degree in Mechanical Engineering from Purdue University. He teaches courses in

manufacturing, CNC machining, automation, quality control, strength of materials, and

simulation. Professor Higley frequently consults in the area of parametric design,

manufacturing processes, and industrial training.

Yulian B. Kin holds the rank of Professor of Mechanical Engineering with a Phi) from

the Petrochemical and Gas Institute in Moscow. He is responsible for the Mechanical

Engineering Design Laboratory. Professor Kin teaches courses in machine design,

mechanics, fatigue analysis, and reliability and fracture mechanics. His research interests

include stress analysis and fatigue fracture mechanics.

Bernard W. Parsons II holds a Bachelor of Science Degree in Mechanical Engineering

from Purdue University Calumet and holds the title of Technical Supervisor for the

Mechanical Engineering Labs. He is responsible for installing and maintaining all the

equipment used in the Mechanical Engineering Laboratories.

Christopher M. Prochnow holds a Bachelor of Science Degree in Mechanical

Engineering Technology from Purdue University Calumet. A 1998 graduate, he now is

employed as a design engineer by Union Tank Car Company, East Chicago, Indiana.

427

STRETCHY "ELASTIC" BANDS II

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

429
Alan K. Karplus

430
Stretchy "Elastic" Bands II

Alan K. Karplus

Department of Mechanical Engineering

Western New England College

Springfield, MA 01119-2684

Key Words: Elastics, Tension Tests

Prerequisite Knowledge: Have an idea about changes in the load an elastic loop holds as it is stretched

and unloaded.

Objective: To work as a team member in the collection of data, to make plots for near constant rate

loading and unloading of fabricated rubber loops, and to show features which are unique to these elastic

products.

Equipment:

1. Collect fifteen three and one half inch long rubber "elastic" bands of 1/8 inch width, 0.034 inches

thickness, and referred to as 33 rubber bands. These fifteen bands are required to build four group

members: A) two bands each cut and tied with square knots at the cut ends to create a single 4 inch

loop (this is equivalent to an uncut band in starting length), B) two bands each cut and tied with

square knots at the cut ends to create a single 6 inch loop, C) four bands each cut and tied with

square knots at the cut ends to create a single 12 inch loop, and D) six bands each cut and tied with

square knots at the cut ends to create a single 18 inch loop. Then clearly designate the group as

Group 33. Without the designator of elastic band size, "group" refers to the four members alone:

loop size A, loop size B, loop size C, and loop size D. Most office supply houses have number 33

size elastic bands.

2. Fifteen foot long Tape measure.

3. Mounting board (2 in. by 1 in. by 30 inch) with a six penny nail inserted one inch from one end on

the 2 inch by 30 inch face, and to which the twenty foot long scale can be attached. The 30 inch long

board should be clamped to a table that is 15 feet long parallel to the long length. C-clamps can be

used to secure the board and the tape measure once the tape measure has been wrapped with a

protective material. The zero of the measure should be at the nail.

Safety Goggles

Heavy work gloves

Load scale for loads to 15 pounds or 7.5 kg. A scale with a capacity to 10 pounds or 5 kg. may be

helpful, if available.

Micrometer or vernier caliper.

Data page with 25 lines and nine columns for each loop to be tested. For the loop size A the

measurements are taken at one inch increments starting at a value of four inches and are to be listed

in the first column. The next two columns are used in pairs to record load and unload for each elastic.

Be sure to label columns and include units of measure selected. For the remaining group members,

B, C, and D, the starting length and increment size change as follows: at one and one-half inch

increments starting at a value of six inches listed in the first column for group member B, at three

,

5.

6.

.

8.

431
inch increments starting at a value of twelve inches listed in the first column for group member C,

and at 4.5 inch increments starting at a value of 18 inches listed in the first column for group

member D, respectively.

9. A Spreadsheet such as EXCEL TM is recommended. However, all work performed on the spreadsheet

can be done by hand.

10. 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 approach is to stretch each rubber loop (LOADING LINE) at a near constant rate and to unstretch

(UNLOADING LINE) it at the same near constant rate while recording the load present at each stretch

point. One team member should do the loading and read the load at each position while the second team

member should record the data. Try to load and unload the elastic at a constant rate, and about the same

rate for each loop so that meaningful comparisons between loops can be made. Both team members

should work on the data analysis, make observations from the computations and plots, and formulate

conclusions.

In each group there are four members which are: A) two bands cut and tied in series with square knots to

represent an original len_h rubber band (do not use an original rubber band because the force to stretch

the band is excessive in relation to the loads needed to stretch the fabricated loops), B) two bands cut and

tied in series to create a six inch long loop, C) four bands cut and tied in series to create a twelve inch

long loop, and D) six bands cut and tied in series to create an eighteen inch long loop. Each elastic band

is initially three and one-half inches long and when cut, is seven inches long.When two cut bands are

tied end-to-end, the effective length of each elastic is six inches, and can be less when tied to make a four

inch loop. The selected loop lengths given earlier are based on an average loop length and experience.

For this experiment each loop is stretched to six times the initial loop length to obtain a strain of 500

percent which is defined as final length minus initial length divided by the initial length.

To efficiently record the data, to process the data that has been collected, and when a spreadsheet is used

consider making a column of deformation that starts at four inches and ends at 24 inches (LOADING

LINE) and returns to four inches (UNLOADING LINE), or starts at six inches and ends at 36 inches

(LOADING LINE) and returns to six inches (UNLOADING LINE), or starts at twelve inches and ends

at 72 inches (LOADING LINE) and returns to twelve inches (UNLOADING LINE), and or starts at

eighteen inches and ends at 108 inches and returns to eighteen inches for group members A, B, C, and D,

respectively. Enter the collected data into the spreadsheet and the make a plot for the entered

deformation - load data. In all cases there are 21 deformation entries in the data sheet. The A member

has loads recorded at of 4.0, 5.0, 6.0 inches, etc. while the B member has loads recorded at 6.0, 7.5, 9.0,

10.5 inches etc. with member C loads values recorded at 12.0, 15.0, 18.0, 21.0 inches, etc. and member

D has loads recorded at 18.0, 22.5, 27.0, 31.5, 36.0 inches, etc.

At each deformation position a computation for engineering strain and engineering stress can be made.

Engineering strain is the length (L) at any displacement minus a reference displacement (R) divided by

the reference displacement (R) or (L-R)/R. For the A loop, four (4) inches is chosen as the reference

dimension (R) for this experiment. Engineering stress or (P/A) is the load (P) divided by the cross

section area (A) of the loop. Note that the loop has two strands carrying load. Compute the strain and

stress for the collected data. Make a second plot for the stress and strain found. As presented above, the

increments used provide a strain of 500 percent.

Increments for the area under the LOADING LINE are computed separately from the UNLOADING

LINE. The totaled incremental areas each represent the energy used to stretch and unstretch the loop,

432
respectively. Now compute the area under the curves with trapezoidal increments. First the upload curve

and then the down load curve. A spreadsheet cell should be used to store each trapezoidal area

increment. The trapezoidal increment is computed by forming the average of two stresses and

multiplying by the change in strain. The total area under a curve can be found by adding the incremental

areas in a column, and is the energy related to each curve. The difference between column totals found is

the hystersis. A ratio between the difference and the upload curve area when shown in percent finds the

portion of energy lost to internal friction or hystersis. Be sure to check UNITS.

An informative comparison for the group of four rubber loops tested can be made by plotting and clearly

labeling first the load deflection data for all elastic loops on one set of axes and secondly the stress -

strain data for all elastic loops on another set of axes. Note how the stress-strain plot curves compare

favorably, and the percentage of energy allocated to hystersis is seen to be similar while the load -

deflection plot clearly shows the change in length and very similar loads for each elastic loop.

Preparation:

Prepare the Mounting Board by placing a six penny nail into the 2 inch by 30 inch surface of the board

one inch from the three surfaces at one end. Place, and then clamp the board onto a table parallel to a 15

foot long edge. Secure the 'zero end' of the tape measure at the nail and attach to the board after

wrapping the tape measure so it is protected and not covered so that the scale can be seen. Similarly,

secure the other end of the tape measure at the 15 foot mark. The experimenter should now be able to

place an elastic loop over the nail and extend a long loop elastic up to 15 feet.

In each group there are four members which are A) two bands cut and tied with square knots to represent

an original length rubber band, B) two bands cut and tied in series to create asix inch long loop, C) four

bands cut and tied in series to create a twelve inch long loop, and D) six bands cut and tied in series to

create a eighteen inch long loop. Each cut elastic band is initially three and one-half inches long and

when cut, is seven inches long. When two cut bands are tied end-to-end, the effective length of each

elastic is often six inches. However, shorter effective lengths can be used depending on the location of

the square knot in relation to the end of the cut band and the chosen loop size. Fifteen number 33 elastic

bands are required to build four Group 33 members: A) two bands each cut and tied with square knots _

at the cut ends to create a single 4 inch loop, B) two bands each cut and tied with square knot at the cut

ends to create a single 6 inch loop, C) four bands each cut and tied with square knots at the cut ends to

create a single 12 inch loop, and D) six bands each cut and tied with square knots at the cut ends to

create a single 18 inch loop.

Secure several rubber loops of each length for a group to be tested (if one breaks, a replacement is

readily availableY). Measure the length, thickness and width of the loop and record the results. Group 33

elastics are approximately 0.034 inches thick, 1/8 inch wide. Remember there are two strands of each

loop carrying load. Now compute the cross sectional area.

Prepare the data sheet with 25 lines and nine columns. Make a column of deformation with 21 data

entries that starts at four inches, has 1 inch increments, ends at 24 inches (LOADING LINE) and returns

to four inches (-UNLOADING LINE), or starts at six inches, has one and one-half inch increments, ends

at 36 inches (LOADING LINE) and returns to six inches (UNLOADING LINE), or starts at twelve

inches, has three inch increments, ends at 72 inches (LOADING LINE) and returns to twelve inches

(UNLOADING LINE), and or starts at eighteen inches, has four and one-half inch increments, ends at

108 inches and returns to eighteen inches for group members A, B, C, and D, respectively. Enter the

Be sure to use the SQUARE KNOT as its cousin, the "Granny Knot" will creep along the elastic when the loop is pulled

and destroy the experiment.

433
collected data into the spreadsheet and then make a plot for the entered deformation - load data. In all

cases there are 21 deformation entries in the data sheet. The A member has loads recorded at of 4.0, 5.0,

6.0 inches, etc. while the B member has loads recorded at 6.0, 7.5, 9.0, 10.5 inches, etc. with member C

loads values recorded at 12.0, 15.0, 18.0, 21.0 inches, etc. and member D has loads recorded at 18.0,

22.5, 27.0, 31.5, 36.0 inches, etc.

In the case of the loop A, measurements are to be taken at one inch increments starting at a value of four

inches listed in the first column and end at the 24 inch position. The remaining columns are used in pairs

to record load and unload for each elastic size. Be sure to label the load columns in pairs (LOADING

and UNLOADING) and include units of measure selected. The first LOADING value is made at the

four inch position. A position is designated where the hook of the load scale attaches to the rubber loop

and is sited on the tape measure. The last LOADING value at 24 inches should be the FIRST

UNLOADING value at 24 inches because the UNLOADING values are recorded for decreasing

positions.

In the case of the loop A when the extension exceeds 20 inches you must make a concentrated effort to

keep the current loop under load. DO NOT UNLOAD or LOOSE LOAD on the scale on the upload

because the loop will be unloaded and the upload data will not be represent near constant rate loading.

This becomes an increasing challenge as the loops become longer. With the longer loops unloading

needs to continue carefully so that meaningful data is collected. Remember elastic bands creep and

hesitation in the loading and unloading process can impact findings. A steady rate of loading and

unloading is important. In case a loop breaks when under test, COMPLETELY redo the test. Special

efforts are needed to record load values for the loops B, C, and D.

In preparation for a test run place a designated rubber loop over the nail and through the hook of the load

scale. Check that a load measurement can be made at the four inch mark on the tape measure. Be sure

the operator of the load scale has safety glasses on and is wearing the heavy gloves. These safety devices

will protect the operator if the elastic loop breaks and the spring scale unloads and the elastic loop flies

around.

Procedure:

1. Tensile load - deflection tests are to be performed on Group 33, a group of four member rubber loops

with each loop prepared from three and one half inch long rubber bands of 1/8 inch width (number 33)

rubber bands. 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 stretch a loop, and as this is done

fit a near constant rate, record the load to stretch the rubber loop at each added inch. For the loop A start

at four inches. Continue with one inch increments until the length of the loop is 24 inches. Next, unload

the loop at the same rate as was used to load the loop taking load measurements at each inch of reduced

length. Remember the load value at the 24 inch position is the same for the last LOADING position and

the end of UNLOADING column on the data sheet. As the loop is unloaded fill the UNLOADING

column backwards, i.e. from 24 to 23 to 22 inches, etc. The recorded data is defined as "raw data" for

elastic loop A of Group 33 which is the first elastic loop tested. Be sure to label the length of the rubber

loop tested, and measure and record its thickness and width.

2. The first comparison to be made is for the shape of loading and unloading paths for load/deflection

data. Repeat step one, above, for loops B, C, and D. Start at 6 inches, use 1.5 inch increments, end at 36

inches, and return to 6 inches for loop B, start at 12 inches, use 3 inch increments, end at 72 inches, and

return to 12 inches for loop C, and start at eighteen inches, use 4.5 inch increments, end at 108 inches,

434
andreturnto 18inchesforloopD.At eachdeformationlevel,entertheload.MakeanXY 2 or Scatter

Plot of the data. The horizontal axis should be Deformation in inches while the vertical axis is Load in

pounds. Label the Load - deflection line as Loop A - Group 33. The approach to use with EXCEL TM is

to make the Loop D plot first and place axes labels and a Plot Title "Elastic 33 Load - Deflection Group

Comparison". Remember the loop D has the greatest length, check the 108 inches, while the other loops

have less. Next INSERT the C data by selecting the data and dragging it onto the plot. The data will be

plotted to the appropriate scale and the series labeled. Repeat for the process for B and A data.

The applied load - deflection plots on the same graph show magnitude changes. The largest load carried

by each loop should be clearly evident on the right hand end of the loop deflection axis when the Load

axis value is read. Note ira trend appears which shows that, in general, the longer loops carry the same

load.

3. The second comparison is dependent on two modifications made to the raw data. The first

modification is to define the engineering strain as the ratio computed by taking the measured loop length

minus the starting length and dividing this quantity by the initial length. For all loop A use four inches as

the initial length, and for loops B, C, and D, six, twelve, and eighteen inches, respectively. This means

that the first value of strain is zero with UNITS of inches/inch and strain units of 0.25 in./in, are used.

The strain is to be plotted on the horizontal axis and should start with zero and end at five.

The second data modification is to divide the load by the cross-sectional area of the original rubber loop.

For Elastic 33, the area is 0.0625 in. by 0.125 in. times 2 (number of strands holding load). This

computes the engineering stress in the loop which has UNITS of pounds per square inch in the English

system and is to be plotted on the vertical axis. Again prepare an XY or Scatter Plot with the modified

data. This will be a stress-strain plot for the elastic or rubber loop. Label the line on the plot as Loop A -

Group 33.

Repeat the strain and stress calculations for loop B, C, and D, and make separate stress-strain plots for

each elastic. Then add this data to the same stress-strain plot as for Loop A and label each line.

Remember in EXCEL TM to prepare on plot and then select and drag onto the plot the other sets of data.

Note the similarities between these curves on the composite plot for the Number 33 Elastic Loops. If the

effect of initial elastic length and original cross sectional area are considered, the stain range of 5 times

or 500 percent is the same for each rubber loop and the stress ranges are comparable. How closely do the

four stress - strain plots resemble one another?

4. Areas under each of the stress/strain curves are to be found by approximation. An approach is to

represent the area between strain values as a trapezoid and to sum the areas of all the trapezoids to obtain

the area under the LOADING line. The summing of trapezoids is repeated for the UNLOADING line.

Note that the trapezoid has a 'height' in stress units of pounds per square inch and that the 'width' of the

trapezoid has strain units of inches per inch. The product of stress times strain becomes inch-pounds per

cubic inch. In summary, the difference between these sums is the residual often referred to as hystersis.

The hystersis represents the energy consumed in the deformation process. Compute the portion of the

UNLOADING LINE energy is of the LOADING LINE energy. Then subtract this value from 100

percent to find the percentage of energy lost to hystersis.

What can be presented about the energy differences between the loops A, B, C, and D? A rapid visual

comparison is found when the stress/strain plots are super-imposed on one another. This shows the

common features such as the LOADING lines as well as differences such as for the UNLOADING lines

2Be sure to make a plot of two variables ,andNOT a line chart as is the usual default setting on a spreadsheet.

435
between the four rubber loops from zero to 500 percent strain. Note that the area term represents

ENERGY. When English units are used, the product of pounds per square inch times inches per inch

becomes inch-pounds per cubic inch.

What relationship can be found between LOADING energy, UNLOADING energy, and hystersis? A

table of rubber loop size with columns of LOADING, UNLOADING, an hystersis can show that about

half the energy is assigned to hystersis

Comments:

1. To aid the instructor in the execution of this experiment, a sample for loop A of Group 33 is shown

below. Figure I presents the data. Note the starting position for deformation at 4 inches and the load

values at 24 inches. In Figure 2 the upload and download curves are seen. Figure 3 is presents the

stress - strain plot for the data seen in Figure 1. Deformation and load values have been presented as

strain values in column four, upload stress, download stress in columns five and six and the

trapezoidal areas between strain increments in columns seven and eight with total work done in nine

and ten.

To make a hand calculation for the 6 inch displacement: A. strain [(L-R)/R] is (6-4)/4 = 0.5 and B. the.

upload stress (P/A) is 0.25 pounds/(2*0.034* 1/8) in. sq. or 29.41 psi. as seen in Figure 3, column five.

In column seven of Figure 1 is C. the area under a part of the upload curve as 3.68 in-lb, per cubic inch

which is found by averaging 0 and 29.41 = (29.41 / 2 =14.71) psi. and multiplying by 0.25 in./in, which

is the change in strain increment. For the incremental download the energy computed is 1.84 in.-

lb./cubic inch found by averaging 14.71 and 0.0 and multiplying by 0.25.

The sum of the incremental work is found in columns nine and ten. A comparison of the total download

energy of 367.65 in.-lb./cubic inches (found by adding all the incremental energies) to the upload value

of 794.12 in.-lb./cubic inch shows a ratio of 0.463 or 46.3 percent. The hystersis value is likewise 100 -

46.3 or 53.7 percent which represents the energy consumed.

2. Figures 4 and 5 show a comparison of the four Group 33 Cut Band Loops for the Load - Deflection

and Stress - Strain presentations, respectively. Note the differences in load for the four loops.

Remember the loops were manufactured and the loaded length of each elastic may be different

length. ,

3. To provide added perspective the lengths of the loops prepared which number 33 elastic bands can

be changed. One requirement for a rapid comparison is to keep the strain increments at 0.25 and the

total strain at 500 percent. Loops of 4 inches, 8 inches, 16 inches and 32 inches provide stress -

strain plots that superpose readily on the Group 33 length selections used in this experiment.

° Another approach is to change the elastic size. Two sizes have been considered: 1) A 1/16 inch wide

or number 19 rubber band can be tried. The number 19 adds a valuable perspective to the data base

and can enhance the experiment. However, be aware that the loads will be less and a different

capacity scale with different increments should be considered. 2) Elastic band size 54 can be used,

too. In this case three significant observations are noted. The first observation is that when the size

54 bands which are 1⁄4 inches in width were cut and tied - and pulled - in the tying process that the

material in the vicinity of the knot was severely distorted, so much so that the elastic material

changed color from brownish to a whitish hue. This coloration showed that the structure of the

rubber in the bands had changed. Note this occurs with the number 33 and 19 bands, also, but the

visual impact is not as strikingly evident!. The second observation is that sometimes the knots crept

along the distorted band ends and the loop separated, especially under loads approaching five

436
pounds. The third observation is that the change in cross section at the knot location and five to ten

knots lengths to either side of the knot creates a "jog" in the loop so that the loop becomes noticeably

altered which destroys the idea of a uniform cross section loop.

. The author was able to obtain solid rubber band material to construct "homogeneous" style loops

with a single knot. This elastic is used for rubber band model aircraft when the builder/pilot selects

his/her own rubber band length. The band often is available from a hobby store as a 96 inch long

rubber thread, 3/16 inch by 0.034 inches in cross-section. Test results are similar. However, the

model aircraft rubber band (rubber thread) exhibited a strain limit of 350 percent in contrast to the

500 percent for loops.

. Reference to Stretchy "ElastiC' Bands from New'97 can lend added understanding to how not only

the impact of changing elastic size effects the stress stress-strain findings for elastics 33, 54, and 84,

but how the work in this experiment shows very similar stress-strain plots for strains to 500 percent.

However, the New'97 experiment used bands in the "as received" condition. A comparison of the

Number 33 band from Stretchy "Elastic" Bands shows that the maximum load at 24 inches

elongation is 5.5 pounds in contrast to 3.5 pounds for the manufactured loopT This leaves the

manufacturing process as an investigation challenge. Hint: Most elastics are cut to width

perpendicular to the axis from extruded "elastic band" cylinders.

Acknowledgments:

The author is appreciative of the assistance provided by Mr. Richard DeCelle, Mechanical Laboratory

Technician, Mr. Peter Bennett, Mechanical Laboratory Machinist, and by Jason Misiaszek in the

recording of data.

437
Cut Bands used to make loops

A two unit loop

displacement loading

in upload

Ib

4 0.00

5 0.00

6 0.25

7 0.50

8 0.50

9 0.63

10 0.75

11 0.88

12 1.00

13 1.13

14 1.25

15 1.25

16 1.50

17 1.63

18 1.75

19 2.00

20 2.13

21 2.38

22 2.75

23 3.00

24 3.50

Band cross section

0,034 in. by1/8 times 2 tendons

stress Inc work

download strain upload download up

Ib psi psi in-bl/in^3

0.00 0.00 0.00 0.00 0.00

0.00 0.25 0.00 0.00 0.00

0.13 0.50 29.41 14.71 3.68

0.25 0.75 58.82 29.41 11.03

0.25 1.00 58.82 29.41 14.71

0.25 1.25 73.53 29.41 16.54

0.38 1.50 88.24 44.12 20.22

0.38 1.75 102.94 44.12 23.90

0.38 2.00 117.65 44.12 27.57

0.38 2.25 132.35 44.12 31.25

0.50 2.50 147.06 58.82 34.93

0.50 2.75 147.06 58.82 36.76

0.50 3.00 176.47 58.82 40.44

0.50 3.25 191.18 58.82 45.96

0.63 3.50 205.88 73.53 49.63

0.75 3.75 235.29 88.24 55.15

0.75 4.00 250.00 88.24 60.66

1.00 4.25 279.41 117.65 66.18

1.25 4.50 323.53 147.06 75.37

2.00 4.75 352.94 235.29 84.56

3.50 5,00 411.76 411.76 95.59

Down load

Total Work

down Upload Download

in-lb/in^3 in-lb/in^3 in-lb/in^3

0.00 0.00 0.00

0.00 0.00 0.00

1.84 3.68 1.84

5.51 14.71 7.35

7.35 29.41 14.71

7.35 45.96 22.06

9.19 66.18 31.25

11.03 90.07 42.28

11.03 117.65 53.31

11.03 148.90 64.34

12.87 183.82 77.21

14.71 220.59 91.91

14.71 261.03 106.62

14.71 306.99 121.32

16.54 356.62 137.87

20.22 411.76 158.09

22.06 472.43 180.15

25.74 538.60 205.88

33.09 613.97 238.97

47.79 698.53 286.76

80.88 794.12 367.65

% of Upload 46.30

Figure 1. Elastic 33 Cut Band Loop A Data

438
Group 33 Loop A Load Displacement

3.5

3

2.5

__ 2

|

qD

t_

o 1.5

,_1

0.5

0

0 10 2O

Displacement - in.

upload

.-m-- download

Figure 2. Elastic 33 Cut Band Loop A Load Deflection Plot

439
Group 33 Stress Strain Loop A

Q.

!

250.00-

200.00-

150.00

100.00

50.00-

0.00!

0 2

Strain

4 6

upload

down load

Figure 3. Elastic 33 Cut Band Loop A Stress - Strain Plot

44O
Group 33 Load Displacement Plots

|

O

..I

4.5

3.5

2,5

2

1.5

1

0.5

0

ji!iiiiiii!ii!i!iiii!iiii!i  ̧

i i iii!ili! i: iiiii iiiii i t iiii_iiiiili_iiiiiiiii_ili;

iiiiiiiiiiii_i!i_iiii!ii_iiifiiiii_iiiiiiiiiiiiiilil

::::::::::::::::::::::::::::::::::::::::::::::::::::

,:,:.:.:.:.:.:>:,:.:¢,;,;+:,:.:+:,:.:.:,:+:.

::::::::::::::::::::::::::::::::::::::::::::::::::

!i!ili!i!iigiiiiiiiiiiiiiiiiiiiiii,g,i!.i

.,.-,.,.,.

i ......

:!:i:!;!:i:i:i:i:::":::i:i:!:i;i:;

0 20 40 60 80 100 120

Dis placement --Inches

---e-- upload

-.-e-- download

Series3

•_ Series4

Series5

I _ Series6

I

I--+.-- Series7 Series8

Figure 4. Elastic 33 Cut Bands Load - Deflection Plot Comparison

Series 7 and 8 Loop A, Series 5 and 6 Loop B

Series 3 and 4 Loop C, Upload and Download Loop D

44]
Group 33 Stress Strain Plots

500.00

400.00

200.00.

--e-- upload

downlo_l

--6-- SerL_,s3

Series4

Ser_S

--e-- SerL_,s6

Series7

-- Series8

0.5 1 1.5 2 2.5 3 3.5 4

Strain

4+5

Figure 5. Elastic 33 Cut Bands Stress -- Strain Plot Comparison

Series 7 and 8 Loop A, Series 5 and 6 Loop B

Series 3 and 4 Loop C, Upload and Download Loop D

442
ALAN K. KARPLUS

Alan K. Karplus is Professor of Mechanical

Engineering at Western New England College,

Springfield, Massachusetts. He has a

Bachelor's degree from Tufts College, a

Master's degree from Iowa State University

and a Ph.D. from Colorado State University.

He has been involved with the freshman

engineering program, coordinates the senior

mechanical engineering laboratory program,

teaches 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.

443

PRODUCING PDF FILES USING

ADOBE ACROBAT CAPTURE V2.01

Alfred E. McKenney

516 Fairfax Way

Williamsburg, Virginia 23185

Telephone: 757-221-0476

e-mail HDJC41A@prodigy.com

445
Alfred E. McKenney

446
 MSET

l( Experiments in Material Science ))

James A. Jacobs _///

_ ISBN: 0-13-648486-7_

Containing over 300 peer-tested experiments and demonstrations that have

been presented at National Educators' Workshops over the last decade.

Sponsored by NASA, NIST, the Department of Energy and Norfolk State

University, the NEW: Update conferences and the cooperative efforts of

over 1000 educators, engineers and scientists made this CD-ROM possible.

Laboratory experiments and classroom demonstrations that you

can modify to suit your teaching objectives, environment, and

students' needs.

Access to instructional aids developed by hundreds of materials

educators and industry specialists.

Provides students with "hands-on" activities that cover the full

range of materials science and technology--topics such as

woods, metals, and emerging technologies including processing

and structures of advanced composites and sol-gel ceramics.

Flexibility---emphasis is placed on low-cost, multi-concept

exercises in recognition of the many settings in which materials

education occurs.

Allows you to read, navigate, search for other experiments and

documents, print and edit.

This CD-ROM has captured both classical and new and

innovative experiments and demonstrations.

To reserve your desk copy, please contact your local Prentice Hall

Sales Representative, or call Faculty Services at 1-800-526-0485.

_ www.prenhall.com

447
Producing PDF Files Using Acrobat Capture V2.01

(capture processv2.wpd)

Original prepared in 1996 by Alfred E McKenney for NEW:Update Lab Experiment Project

Rev: January 27, 1999

Overview

The PDF files will be produced using Acrobat Capture to scan and process the hard copy

proceedings. The sizes of the output files are dependent on the number of pages and the

number and size of the graphics contained in the paper. Each formula, table and illustration is a

separate graphic.

The first part of the Capture process involves scanning clearly-printed* hard copy documents to

produce an intermediate graphics file. Usually this is a TIF format. This can be done at less than

a minute a page, using a scanner the speed of the UMAX Vista S-12. The intermediate graphics

pages can be Astored_= for final processing later, unattended.

After processing through the second and final step of Capture, which involves optical character

recognition (OCR) and page formatting, an ACD file is produced. Although a preliminary PDF

file can also be produced at this time, there are usually questions raised in the OCR process. The

documents should, therefore, be proofed in a third step, using Capture Reviewer. Capture has

previously marked the Asuspects= to make the job easier. This review may take four or five

times as long as the scanning process, depending on the complexity of the paper and the subject

knowledge of the reviewer, that is, someone familiar with the terminology and conventions of

technology. A five page paper, clearly printed, containing only text might be proofed in about

five minutes. Once the review is complete, the ACD is finally saved as a PDF. These PDFs

should be checked by using Acrobat Reader and sampled by printout to ensure the validity of the

Capture and Review process.

* Clearly-printed means a paper submitted using:

A laser printer. A good ink jet printer is acceptable _ but not dot matrix printing.

Body type size, 11 to 12 pt.

Clear type, preferably a serif (Roman) face. Sans-serif is acceptable.

No underscores. Use italics, if possible.

It should be noted that if the paper were available in digital form, the Acrobat PDF Writer

program could be used to quickly and accurately produce the PDF file directly, without need for

the Capture program. However, this means that the formulas, tables and graphics would have

had to be created within the word processor, as well as the text, so it is unlikely that many

papers will be produced this way. Thus, there is little need for submission by diskette when

clear hard copy is available.

Note: The following procedure describes the use of a UMAX Vista S-12 scanner, utilizing a

Twain driver. Adobe recommends the use of an ISIS driver for full functionality, if possible. The

procedure may differ slightly for other scanners or when using an ISIS driver.

448
The Procedure

up

Start the PC, and Windows, making sure that the UMAX scanner is ON and that the middle

green pilot light is on steady (not flashing) upon completion of boot up. Start Acrobat Capture

V2

If Capture does not recognize a valid scanner, it will be necessary to set it up. Go to Input/Setup

Scanning Device. The Device field may be grayed out. If so, hit the button to the right with the

three dots. This will allow the correct driver to be selected. Even after selecting OK, the field

may still be grayed out, but the scanner will be recognized as indicated by the green Scan arrow.

Select the papers to be Acaptured.= If there are any Afull text=- papers, without graphics, tables

or formulas, check to see if there is a diskette for these papers which can be processed directly

with PDF Writer. The balance (most of the papers) will be processed with Capture.

Scan

Verify that AUMAX/VistaScan_-_ (the Twain driver) is selected for the input device.

In the Input/Setup Input Folder drop down menu, make sure that the box, ACollate files by

common prefix__ is checked. This will collate each page of a paper into a common ACD file

during the Process operation. Collation uses the first four characters of the paper name, the

prefix, to do this. This means that the name of each individual paper must have a unique

Aprefix_= as defined by this collation logic. If this box is not checked, each page scanned will be

Processed independently into a separate ACD file and will require the use of Acrobat Exchange to

merge the resulting PDFs later, when required.

Select the AEMSET _ folder (or the appropriate folder) to receive the scanned TIF images.

Make sure the scanner glass is clean.

Insert the first page of the first paper into the scanner, face down.

The top edge goes to the back, flush with the top (far) edge of the scanner glass. The long

edge of the page goes flush with the right edge of the bed.

>>> The accuracy of the results is highly dependent on the text being horizontal. If the

page has been reproduced slightly askew, compensate by turning it on the bed slightly.

Check this later in the preview process.<<<

Select ASCan.=_

449
Enterthe paper name or number in the Document Name box. (See above for naming

requirement). Make sure the starting page number assigned is 0001. (If you need to rescan a

page, use that page---s number.) File format default is TIF.

Select AStarteMake sure the settings on the VistaScan32 screen are:

Line art or B/W Document

Reflective

300dpi

100%

Select APreview= to set the frame size. Leave the original page margins. Make sure there is a

normal margin around all text, and graphics, including titles. Make sure the text is horizontal.

Note: When using an ISIS driver, the Twain setup screen will not appear. It is necessary to enter

these settings ahead of time in the ISIS setup box.

Do not adjust the page size for partial pages, such as the last page of a paper, as this causes the

text to be centered vertically. Determine whether or not it is desired to exclude the original page

numbers if this paper is from a larger document.

Except for spot checks, it is not necessary to preview again unless the page layout changes or it

is necessary to check for horizontal text.

Select AScan__ when the Preview is OK.

When the scan of the current page is complete and there are additional pages remaining to be

scanned in this paper, select AScan Next Page= in the Scan Document window. The present

page can be removed and the next page can be inserted as soon as the scan is finished. It is not

necessary to wait for this box to appear.

Start at the beginning of the Scanning process with the next paper, until all papers in the batch

are scanned satisfactorily

>>> It is important that the pages in a paper be scanned sequentially. If a page has been

scanned out of order, it is important to note this in the Log, so the error can be corrected.

Except for a long document, it will usually be easier to begin scanning of the document

again.<<<

When the last page of the current paper has been scanned, select ADocument Finished._--

>>> It is important to check that the number of TIF files is equal to the number of pages

in each document. <<<

Process

45O
Select the TIF files to be converted to PDF and ACD files from the AEMSET _ folder. First,

clear the selection by selecting any file. Then select the papers desired by holding down the Shift

key while selecting. Be sure to select all the TIF images (all the pages) in each paper to be

processed.

Select the AEMSET Out_- folder in the output area. Make sure that the folder is set to AAcrobat

Capture ACD._ =_

Select AProcess= and wait for the files to be processed.

>>> This processing can be done over a lunch period or overnight as it is completely

automatic and takes some time to complete. Therefore, it is best to Scan as many papers

as possible while in attendance at the PC, leaving Process for later.<<<

Review of Capture Process Results

Look for any error messages. Make sure that the job went to completion and that there is an

ACD file for each paper. There may also be a number of ACI files which contain the graphics for

each paper. The ACI files will not be visible in the folder, but they are there.

The next step is to EDIT, or Areview_ and correct, the ACD files in the Capture Reviewer program

to correct any scanning or process errors.

Reviewing and Correcting PDF Files Using Acrobat Reviewer

(See the Overview section)

To begin the Review process, either start Capture Reviewer from Windows or double click on the

ACD file which you wish to edit. By double<licking on the ACD file, you will automatically

start Capture Reviewer and open the selected file. If you start from Windows, you will need to

Open and locate the ACD file in question.

Minimize the Capture program if necessary.

Once the file is open, you will see yellow and blue text and graphics blocks marking Asuspects-z-_-

the process program has identified. Included are words with less than the specified confidence

level. For this project we will normally preset a 95% confidence level. Recognition suspects are

highlighted in yellow. Spelling, font and alphameric suspects are highlighted in blue.

Press TAB to move the cursor to the first suspect. The corresponding graphical representation of

that block appears in enlarged format at the top of the screen.

If the word is correct, press Ctl-Tab to accept it and move to the next suspect. If this is a

technical term and you know the spelling is correct, it can be entered in the Custom

451
Dictionary.Thiswill prevent it from being highlighted in future processes. To do this,

select Suspect and Add Word to Custom Dictionary.

If the word needs to be corrected, double click to select the whole word or move the

cursor to the letter(s) needing correction and delete and add as required until the word is

spelled correctly. The case or font may need to be corrected. If so correct them.

In some cases, it will be necessary to substitute the graphic representation for the letters

recognized by the Capture OCR process. This will normally be the case for formulae,

graphics and handwriting. To do this, select Edit, then either Convert Text Block to Image

(Ctl-Sh-G) or Convert Text Line to Image (Ctl-G). It is preferable to convert only the line if

the rest of the block is fairly accurate. Converting to Image means that the text is no

longer text and is not searchable. Do not substitute a graphic image for paper titles,

authors or key words as this will prevent proper indexing of papers.

Experience will show when it is best to use Convert Text Block to Image or Convert Text

Line to Image. The objective is to minimize the amount of text converted to graphics.

However, the best representation of some text may actually be the graphic line or block,

such as for formulae or mathematical and scientific symbols. See the new facility for

inserting symbol characters. This should save considerable text editing effort or

replacing an otherwise valid text line with a graphics image.

When the ANo further suspects-z-_ message is seen, go back to page 1 and Tab to be sure

that all suspects have been handled.

>>> If any page has numerous errors or is unreadable in part, that page can be re-Scanned by

placing the corresponding paper file name and page number in the Scan box. This will replace

the corresponding TIF file. The paper can then be re-Processed. Alternatively, to avoid

reprocessing, the page can be rescanned with a unique name. Then use Acrobat Exchange to

delete the offending page and insert the new page. (See Rescaning... below)

When rescanning, using the original document name, it is necessary to delete the original ACD

file, otherwise the collate process will add this later scan to the original file.

Saving the Revised Files

Once the entire paper has been corrected and the Rev/ewer prompt indicates, ANo more

suspects,_--- the revised ACD and the new PDF need to be saved. From the File menu, chose Save

as ACD. After the ACD is saved, chose Save As from the File menu. (Save As minimizes the pdf

file size.) Make sure the default file type is Acrobat PDF/Normal and the default (file name) and

PDF extension are correct. Close the Rev/ewer.

Selected PDFs, particularly graphics intensive papers, should be reviewed in the Acrobat Reader

and also printed in part to check the accuracy of the PDF generation. Corrections can be made

by opening the ACD again.

452
Check for correct page sequence.

Rescaning and Correcting Part of a Document

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453

CAST IRON, WROUGHT IRON & STEEL

(HISTORICAL PERSPECTIVE OF PROPERTIES

OF FERROUS MATERIAL)

Archie M. Cooke

Retired Metallurgist

96 Arrowhead Drive

Carson City, Nevada 89706

Telephone: 702-885-8854

455

CAST IRON, WROUGHT IRON & STEEL

(HISTORICAL PERSPECTIVE OF PROPERTIES OF FERROUS MATERIAL)

Archie M. Cooke

Retired Metallurgist

Carson City, Nevada

Keywords:

Cast-iron, Wrought-iron, Steel, Rockwell Hardness

Prerequisite Knowledge:

The Student

I. Should have observed objects made of cast-iron, and

observed its brittle character. (Stove parts, auto engines,

etc.)

2. Should have observed ornamental fences, gates, etc. made

of what is called wrought-iron.

3. Should have been subjected to sales talk of the strength

advantages of some heat treated steel object. (Golf

clubs,knives, gears, etc)

Objective:

The objective of this exercise is to compare the properties

of cast-iron, wrought-iron, and steel in a background of

historical development.

Equipment and supplies:

I. Two pieces of _"X_"X72"wrought-iron bar. (Annealed low

carbon steel would be a suitable substitute.)

2, One piece of _"X_" X30" low alloy carbon steel heat

treated to Rockwell C50.

3. One piece of _"X_"X30" cast-iron. (Machine from any

casting)

4. One five gallon bucket with a bail handle

5. Fifty pounds of lead shot.

6 One hack saw

7. One strong bench with a metal vise.

8. One two handed wrench or hand wheel.

Procedure:

Overview:

For the bend tests the _"X_" bars should be cut to the

lengths specified. One end should be clamped in the

vise, and at 20 inches from the vise face, adhesive tape

should be wrapped around the bar. The bucket should be

hung on the bar with the bail in such a position that the

tape keeps the bucket from sliding away from the 20 inch

position.

Bend Testing the Wrought-iron Bar.

Place a 30 inch long wrought-iron bar in the set-up

described and slowly pour lead shot into the bucket until

the bar bends to a 45 degree angle. Remove the bar and

observe the permanent set.

457
Bend Testing the Steel Bar:

Place a 30 inch long steel bar in the set-up described, and

hang the bucket containing the shot from the wrought-iron

bend test at the 20 inch position. Observe the different

action from that of the wrought-iron bar. Continue adding

lead shot until the bar either breaks or the bucket becomes

full of shot.

Bend Testing the Cast-iron Bar:

Place the 30 inch long cast-iron bar in the test set-up

described with an empty bucket hanging at the 20 inch

position; then, slowly add lead shot to the bucket until the

bar breaks. Observe the fracture faces.

Demonstration of Work Hardening:

Place a piece of the wrought-iron bar in the vise projecting

out about 18inches; then, bend the bar back and forth about

ten degrees until it breaks. Observe that as the process

proceeded it became progressively difficult to bend until a

crack formed and grew until failure. Obviously the bar

became stronger by this cold work. Did we strengthen it

just to break it? What other property did the bar obtain

during the process? Do not say fatigue; such a description

is an old wives tale cautioned against by elementary

metallurgy text books. Consider the fact that the beam

bending formulas in handbooks consider all materials

equal, i.e. The ratio of extreme fiber stress to bending

moment equals the section modulus for all materials.

Demonstration of Strengthening by Twisting:

Place a 72 inch long bar of %"X%" wrought-iron on a table

with one end held by the vise and the other end attached to

a hand wheel or two handled wrench. Twist the bar until

uniform nodes of about one inch spacing occurs. Remove the

bar and compare the stiffness with that of the untwisted

bar. If the bar was crooked before twisting observe the

straightening effect of the twist.

Results Review:

Note the dates of discovery of the various ferrous products

as shown on Figure Apparently Wrought-iron was the only

ferrous material known to mankind at the age of King

Arthur's saga. The student might suggest a correction to

the story of extraordinary properties of his sword named

excalibur. Consider an extraction from an old Norse saga by

Davidson (I) which reads:-"Steinthor .......... hewed with

both hands, but the elaborate sword was of little use when

it came against a shield, and he often had to straighten it

under his foot"

458
Apparently straightening the sword blade under the foot was

a common occurrence in these battles because some blades

were soft. Some have suggested that the sword blades which

were stiff like King Arthur"s instead of soft like

Steinthor's was due to absorption of carbon and inadvertent

heat treatment strengthening; however, laboratory tests of

some of these old sword blades have failed to find any

evidence of carbon absorption.

These blades have been found to be made of thin strips of

wrought-iron hammered together and then twisted. This

twisting, like that in the above demonstration might have

strengthened the blade by cold work. The loss of this cold

work strengthening by inadvertent heating above a

recrystallization temperature might explain why some blades

were soft.

Historical Perspective:

Figure shows that wrought-iron production began in

antiquity and ended in the 1930's when the Aston-Byers

process could no longer command a premium price over low

carbon steel. Having been the primary ferrous product for

over 3500 years, it is worth noting that Bessemer invented

his steel to be cheaper (not better) than wrought-iron.

Cast-iron got its big development by the ability to be

poured in liquid form into molds for muzzle loading

cannons. It has subsequently become the main material for

other items that can take advantage of its superior

fabrication properties. The puzzle is that it took so long

for the discovery of heat treated steel.

We do not know when it was discovered that control of carbon

content could be utilized to strengthen iron. There is some

thought that carbon in a suitable range could be obtained in

wrought-iron by prolonged exposure to carbon at elevated

temperature. We know that such treatment will not get

carbon to diffuse more than a few millimeters into the

surface of solid iron, and that melting is necessary to get

the carbon to distribute uniformly through the iron. Figure

shows that this could not have been obtained until the

crucible process was introduced about 1700AD. The

development of the art of strengthening steel by heat

treatment originated in the tool-steel industry's use of

various alloy additions in the crucible melting process.

The other steel uses were slow to adopt these procedures.

For general structural applications the trade-offs between

cost of extra size of structural members vs cost of extra

heat treatments and alloy elements usually falls on the side

of larger structural members.

459
Iron Ore & _JS._LTING BOWL Wood

Charcoal. " "], 1700 BC . Chips

J.0oTz FmU_XCE I sooBc

Iron Ore & i

Charcoal

Iron Orea Coke y

An J

Pig Iron " )0 ;_n |

,__.__¢uPoL_r...xcz t =_

I I _eOOAD I

ICHILL CASTINGJ

1600 AD I

o

TEMPER I e

OvEN I c3

1700 AD_ •

Malleable White

Case Cast

Iron IEon

[

MG-CE _u_Lz I

zgso _ I

Ductile Gray

Cask Cask

I_on Iron

u Pig Iron

N

o

CONVERTER

1850 AD

OPEN HEARTH

1880 AD

ELECTRIC ARC

Z900 AD

BASIC OXYGEN

1950 AD

FuEnace

Refined

Steel

C_de Steel,

Scrap & Flux

1700

+

i, o,.zNo 1800 I

Stee

IAS_O"-a_ERS4

[ 1920 _O I

I

I=Ita_lon

Wrought

Iron

Crucible

Steel

Figure History Flow Chart

-Iron 2000 BC to 2000 AD

460
Effect of Chemistry of Iron on its History

The convoluted history of iron and steel has

through the centuries been guided by luck

intertwined with the chemical properties of the

metal iron in relation to carbon and oxygen.

This is the story of how the chemistry of iron

and lack of knowledge thereof effected the

history of use of iron and steel. These effects

are:-

(1) Lack of knowledge by prehistoric man of how

to produce a temperature above 2000 degrees.

(2) The fact" that solid iron ore can be reduced

to solid metallic iron by the action of

carbon monoxide gas at a temperature far

below the melting point of iron, the product

being essentially pure iron.

(3) The fact that solid iron when free of carbon

is a very malleable metal,

(4) The fact that iron will absorb carbon when

heated above 2400F degrees in the presence

of carbonaceous material and that the

melting point of iron is reduced by

absorption of carbon to about 2100F degrees

at 4 percent carbone

(5) The fact that if iron in the liquid state

contains between 2 percent and 4 percent

carbon it will upon solidifying by slow

cooling precipitate out most of the carbon

in the form of graphite flakes.

(6) The fact that graphite precipitation can be

prevented by rapid cooling causing the

carbon to combine with iron as iron

carbide resulting in a very hard and brittle

material called white cast iron.

(7) The fact that white cast iron upon prolonged

heating at about 1600F degrees will become

malleable through a graphite precipitation

mechanism which concentrates the graphite as

compacted aggregates instead of graphite

flakes.

(8) The fact that iron with dlssolved carbon

between 1⁄4 and 1 percent can be strengthened

by a heat, quench, and temper cycle.

Discovery of Iron

The first three effects listed above can be

linked to explain the first production of iron by

man. We see that after about 1000 years of

461
bronze smelting_ prehistoric man probably

discovered iron by accidentally mixing iron ore

(iron oxide) with tin ore (tin oxide) during the

reduction of tin ore with charcoal to make

bronze, an alloy of tin and copper. The result

probably left a lump of red hot, more or less

pure iron, mixed with iron oxide and slag at the

bottom of the reduction pot. Prehistoric man

might have treated this lump the same as he would

bronze; i.e. hammer it into shape. This might

have given him the idea that this new material

would be an ideal substitute for bronze; which by

this time was getting scarce due to depletion of

the easily mined copper deposits.

Luck

fourth and fifth effects listed above bring

luck into the equation. Luckily prehistoric man

could not produce a temperature high enough in

his reduction pot to cause the iron to absorb

carbon from the charcoal fuel. If he had, the

iron would have melted and solidified as flake

graphite cast iron which he would have been

unable to shape by hammering. Luckily, the metal

he produced was a malleable metal that later

became known as wrought iron.

Wrought Iron

The first recorded use of iron places the

discovery at about 1700 BC. The early iron

smelting furnace probably was a bowl shaped hole

in the ground, lined with clay, and charged with

a mixture of charcoal and lron ore. It is

assumed that temperature was maintained by

burning the charcoal with air forced in through

clay pipes fed by crude bellows. Figure is a

diagram of the subsequent progressive

developments in iron smeltlng from this primitive

furnace producing wrought iron to the present day

products of steel, malleable iron, white cast

iron, nodular cast iron, and flake graphite cast

iron. In Figure , followlng the direct line of

descendants of the bowl furnace, we have the

Catalan forge replacing it about 700 AD. The

Catalan forge produced wrought iron using

essentially the same process as the bowl

furnace. The Catalan forge was obsoleted about

1800 AD by the puddling furnace which made

wrought iron from blast furnace products by

462
burning out the carbon with iron oxide. The

puddling furnace was subsequently replaced about

1920 AD by the Aston-Byers process of making

wrought iron from steel.

Crucible Steel

In Figure follow the side descendant

of the bowl furnace wherein steel is made from

wrought iron, first in the Wootz furnace and

subsequently in the crucible furnace. These

furnaces utilized the chemical property of iron

exemplified by effect number 8 of the

introductory list, namely, that although a large

amount of absorbed carbon in iron produces a very

brittle solid, a small amount produces a product

which can be strengthened by heat treatment. For

instance, the Wootz process consisted of placing

pieces of wrought iron in a clay pot along with a

carbonaceous material such as wood chips; sealing

the pot; and then heating it in a separate

furnace for several days. Upon removal from the

furnace the clay pot was broken away leaving a

lump of steel. In a similar manner, in the

crucible process, developed about 1700 AD a pot

called a crucible is loaded with wrought iron

plus the amount of carbon and alloying elements

desired in the finished steel The loaded

crucible is then placed in a furnace with a

temperature high enough to melt the charge. The

melted steel is poured from the crucible and the

cruclble is reused.

pray Iron

_alance of Figure shows the

inter-relationships of blast furnace products.

It is postulated that as the size of the Catalan

forge increased to meet larger demands for

wrought iron the ability to heat the charge to

higher temperatures occurred by accident. Then,

lack of temperature control allowed some of the

iron to absorb sufficient carbon to melt and flow

out of the furnace where solidification as flake

graphite cast iron occurred. Such iron was

useless to the smelter who wanted carbon free

wrought iron capable of being shaped by

hammering. This unwelcome molten high carbon

iron running from the furnace eventually was

found to be castable into useable items where

brittleness would not be a problem. To satisfy

this market, the blast furnace was developed

about 1300 AD. This was followed about 1600 AD

by the cupola furnace used to remelt the blast

463
furnace product. For many years thereafter cast

iron from the blast furnace or cupola furnace

dominate6_the iron industry. By 1800 AD the

blast furnace had proven to be such an economical

way to smelt iron ore that its product became the

starting material for nearly all iron and steel

products.

Malleable Iron

Figure

introduction

introduction

cast iron.

metallurglst

shows a gap of many years between

of the blast furnace and the

of white cast iron and malleable

During this time the medieval

probably learned how cast iron

properties are dependent upon the method of

doping and casting. They must have learned how

the properties of flake graphite cast iron varied

with the size and distribution of graphite, and

eventually learned that doping with iron oxide

and rapid cooling completely prevented the

precipitation of graphite. Finally, they must

have discovered the process for the production of

malleable cast iron

As described in a French publication in 1722

AD and still in use today malleable iron is made

in two steps. First, the blast furnace product

composition is adjusted so that rapid cooling

produces white cast iron in which the carbon

remains in solution in the solid metal. Second,

this white cast iron is held at a temperature of

about 1600F degrees for several days during which

time the carbon precipitates as compacted

aggregates; now called temper carbon. The matrix

being more or less depleted of carbon becomes

essentla11y low carbon steel; hence, malleable.

Ductile Iron

The latest development in the fleld of cast

iron was the introduction of nodular cast iron at

about the end of world war two. This followed the

discovery that addition of magnesium and/or

cerium to the ladle during pouring of a cast iron

which would otherwise have been flake graphite

cast iron causes the graphite to collect as tiny

balls rather than flakes. As in the case c

malleable cast iron this depletes the matrix of

most of the carbon resulting in a malleable

product. This product, advertised as "ductile

cast iron" has the advantage over malleable iron

of elimination of the white cast iron middle

production step,

464
References

I. Davidson, H.E., The Sword in Anglo-Saxon England, The

Boydell Press, Woodbridge, Suffolk, U.K.

465
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National Educators" Workshop: Update 98

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