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'q''c100°U56°nT86-3^ A National Forum on

The Future of Automated

Materials Processing

in U.S. Industry

The Role of Sensors

Report of

Workshop I.

December 1985

Edited by:

H. Thomas Yolken

Robert Mehrabian

Sponsored by:

Industrial Research Institute

and

White House Office of Science and Technology Policy,

Committee on Materials, Working Group

on Automation of Materials Processing

In Cooperation with: University of California at Santa Barbara

National Bureau of Standards

C. 2
Cover: An analog representation of an

intensity field pattern of a

10 MHz ultrasonic transducer.
A NATIONAL FORUM ON THE FUTURE OF AUTOMATED

MATERIALS PROCESSING IN U.S. INDUSTRY

. . .THE ROLE OF SENSORS. . .

Report of Workshop

UNIVERSITY OF CALIFORNIA AT SANTA BARBARA

SANTA BARBARA, CALIFORNIA

December 16-17, 1985

Sponsored by:

Industrial Research Institute

and

White House Office of Science and Technology Policy

Committee on Materials, Working Group on Automation of Materials Processing

In cooperation with:

University of California at Santa Barbara

and

National Bureau of Standards
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TABLE OF CONTENTS

Committee on Materials, Ad Hoc Working Group

on Automation of Materials Processing v

Workshop Organizing Committee vi

Introduction 1

Workshop Conclusions . . . ^ 5

Summary of Sensor Needs for:

Electronic Materials 7

Optical Materials 8

Metals 9

Ceramics 10

Polymers 11 Basic Materials. 12

Composites 13

Summary of Sensor Methodologies for:

Process Parameters 14

Dimensional Metrology 15

Materials Characterization (NDE) 17

Surface Properties 18

Adhesion and Interfaces 19

Appendix A - Workshop Reports 21

Appendix B - Summary of Consensus Views 57

Appendix C - Summary of Conclusions Raised at Last Session 67

Appendix D - Workshop Program 71

Appendix E - Workshop Attendees 79

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5^.
COMMITTEE ON MATERIALS, AD HOC WORKING GROUP ON AUTOMATION OF MATERIALS

PROCESSING

Chairman

Dr. H. Thomas Yolken

Chief, Office of Nondestructive Evaluation

National Bureau of Standards

B34M Materials Building

Gaithersburg, Maryland 20899

Members

Dr. Peter Bridenbaugh

Vice President, Research & Development

Aluminum Company of America

Alcoa Technical Center

Alcoa Center, Pennsylvania 15069

Dr. Peter Cannon

Vice President - Research

Rockwell International Science Center

10^9 Camino Dos Rios

Thousand Oaks, California 91360

Dr. Robert Mehrabian

Dean, College of Engineering

1012 Engineering Building

University of California

Santa Barbara, California 93106

Dr. Bryon Pipes

Dean, College of Engineering

University of Delaware

208 Evans Hall

Newark, Delaware 19711

Mr. Jerome H. Schlensker

Vice President, Manufacturing,

Planning, and Support

Cummins Engine Co., Inc.

Mail Code 60202

Box 3005

Columbus, Indiana 47202

Dr . Nam Suh

Assistant Director for Engineering

National Science Foundation

1800 G Street, N.W.

Washington, D.C. 20550

Dr. Benjamin Wilcox

Assistant Director, Materials

Science Division

DARPA/DSO/MSD

1400 Wilson Boulevard

Arlington, Virginia 22209-2308

V
WORKSHOP ORGANIZING COMMITTEE

Co-chairmen

Dr. Robert Mehrabian

Dean, College of Engineering

1012 Engineering Building

University of California

Santa Barbara, California 93106

Dr. H. Thomas Yolken

Office of Nondestructive Evaluation

National Bureau of Standards

B3^^ Materials Building

Gaithersburg, Maryland 20899

Members

;

Dr. John Blair

Director of Research

Raytheon Company

1^1 Spring Street

Lexington, Massachusetts 02173

Dr. Wayne G. Burwe 11

Director of Research

United Technologies Research Center

Silver Lane

East Hartford, Connecticut 06108

Professor L. Eric Cross

Director, Materials Research Laboratory

Pennsylvania State University

University Park, Pennsylvania 16801

Mr. L. Duane Dunlap

Manager, Equipment Development Division

Aluminum Company of America

Alcoa Technical Center

Alcoa Center, Pennsylvania 15069

Dr. Phillip Parrish

Defense Advanced Research Projects Agency

Materials Sciences Division

1^00 Wilson Boulevard

Arlington, Virginia 22209-2308

Dr. H. Kumar Wickramasinghe

IBM - T.J. Watson Research Center

P.O. Box 218

Kitchewan Road & Route 135

York town Heights, New York 10598

Vi
INTRODUCTION

This workshop, "A National Forum on the Future of Automated Materials

Processing in U.S. Industry - The Role of Sensors," was the first of two

workshops to be sponsored by the Industrial Research Institute and the

White House Office of Science and Technology Policy, Committee on Materials,

Working Group on Automation of Materials Processing.* The second workshop

will address the other two key components required for automated materials

processing, process models and artificial intelligence coupled with

computer integration of the system.

The objective of these workshops is to identify and assess important issues

affecting the competitive position of U.S. industry related to its ability

to automate production processes for basic and advanced materials and to

develop approaches for improved capability through cooperative R&D and

associated efforts. These workshops will form the basis for developing

information and recommendations for national direction.

This report is the proceedings from the discussion group portion of the

meeting. A draft of the proceedings, based on written summaries provided

by the discussion leaders, was forwarded to the discussion leaders, the

three closing summary speakers, the Program Committee members and the COMAT

Ad Hoc Working Group. The suggestions received are incorporated in this

final report.

Over the last twenty-five years, and especially during the last decade,

major worldwide changes have taken place that are challenging U.S. industrial competitiveness. Conventional structural materials such as steel,

cement, and aluminum have, to a substantial degree, become commodity-type

materials. Effective and efficient manufacturing processes are urgently

required to compete in this world market. Although the technology embodied

in more advanced engineering materials will most likely slow the spread of

this type of capability to other countries, U.S. competitiveness in advanced

materials will nonetheless also depend on manufacturing effectiveness and

efficiency.

New advanced engineering materials, if they can be manufactured efficiently,

hold the promise of profound beneficial effects on many engineered systems.

They can enable the manufacture of new, innovative, and more efficient configurations of existing products. For example, metal matrix composites

could provide very substantial gains in stiffness and strength over conventional metal alloys. Utilization of advanced materials can also result in

product modifications that enable easier, more economical production methods to be used. The near-net-shape capability embodied in materials processing of advanced metal and ceramic powders can lead to greatly reduced

machining costs.

* See pages v and vi, respectively, for the lists of members of the Ad Hoc

Working Group and the Program Committee for this workshop.
Another benefit to be derived from using these advanced materials and

processes is the savings resulting from the substitution of costly strategic materials. This savings can be illustrated by the examples of metal

surface modification by laser glazing or alloying and by ion implantation.

Advanced materials can also facilitate the development of entirely new

products. For example, objects made of shape memory alloys are able to

"remember” their original shapes after being deformed. Potential applications include mechanical activators and mechanical coupling devices.

Unfortunately, advanced materials require complex microstructures to yield

the desired advanced properties and these complex microstructures are proving difficult to reproduce. This is the case because process models, or the

relationship between process variables and resulting microstructure, is not

well understood and adequate process control schemes are often lacking.

Products made from advanced materials, therefore, often lack reproducibility

and this in turn requires that products be overdesigned. Lack of reproducibility thereby causes a substantial loss of the full potential of

advanced materials. In addition, current production of advanced materials

is often labor intensive and requires costly post-processing inspection.

Reject rates are often high with the rejects typically not identified until

late in the production process thereby resulting in major loss. Systems

based on high rejection rates and extensive inspections are bound to

produce some system failures with accompanying loss of consumer confidence.

In the current state of materials processing, the processing path is

determined by research and development in a controlled laboratory environment. Theoretical and empirical process models, often incomplete, are used

along with sophisticated analysis of properties. Production processes are then set up with process control usually limited to some extrinsic parameters and other parameters such as temperature, pressure, etc. Intrinsic

properties of the materials and other key parameters are usually not monitored during the process to provide closed-loop feedback control. This

appears to be a major flaw in current processing methodology. NDE sensors

are only used after production in an attempt to "inspect in" quality. What

is needed is "built in" quality through automated intelligent materials

processing utilizing a system consisting of process control models, on-line

NDE sensors, feedback controls, and artificial intelligence or expert

systems.

These two workshops were planned because of our recognition that input,

involvement, and possibly cooperative programs involving university,

industry, and government are essential to achieve a timely wide-scale

exploitation of this technology.

The first day of this two-day workshop on sensors dealt with sensor requirements for various processing technologies. The morning plenary

sessions involved a series of resource speakers while the afternoon sessions consisted of a parallel series of discussion groups. In a plenary

session at the end of the day, the discussion leaders then summarized the

conclusions and recommendations that emanated from the discussions.

2
The second day of the workshop dealt with sensor capabilities. The format

was the same as for the first day, with resource speakers in morning plenary

sessions and afternoon parallel discussion groups. The discussion leaders

then reported the findings in a plenary session. A final plenary panel

discussion was held at the conclusion of the workshop.

This introduction and the first three sections of the report were written

by the workshop co-chairmen. The first section is a list of major conclusions that are based both on the written material provided by discussion

leaders and summary speakers and on the oral information exchanged at the

workshop. The next two sections consist of conclusions from each of the

discussion groups. These discussion group conclusions were abstracted from

the written summaries (contained in Appendix A) that were prepared by each

of the discussion leaders. Appendix B contains written remarks by the

three closing plenary summary speakers, Appendix C contains a summary of

conclusions raised at the last session. Appendix D is a copy of the

workshop program, and Appendix E is a list of attendees.

The workshop had 106 participants with 68 from industry, 21 from academia,

and 17 from government.

3

WORKSHOP CONCLUSIONS

1 . A clear consensus emerged concerning the formidable benefits to be

derived from automating materials processes, and sensors were

identified as one of the key ingredients in automated materials

processing systems.

2. Several generic sensing problems were identified that cut across broad

classes of materials. The sensing problems include: characterizing

small flowing powders, determining internal temperature profiles in

solids, measuring liquid/solid interface position and interface

topography and characterizing solid/solid interfaces.

3. A large number of sensing problems were identified that are

applications driven and appear to require somewhat unique solutions.

4. In order to completely define sensor requirements for a specific

process an adequate process model must be developed.

5. There is a need for cooperative research on sensors between related

industries, universities, and government. This is so because in many

cases the required sensor systems will require a multidisciplinary

research and development effort. In addition limited applications for

each sensor will constrain cost recovery through the sale of sensors.

H. Thomas Yolken

Robert Mehrabian

5

SENSOR NEEDS FOR ELECTRONIC MATERIALS

Discussion Leader: L. Eric Cross, Pennsylvania State University

The participants confined their consideration to several of the most

important electronic materials (Si, GaAs, and CdTe) . They reached a number

of specific and useful conclusions.

1. What parameters or properties require sensors for monitoring and

controlling bulk crystal growth?

• Three dimensional temperature distribution in real time.

• Three dimensional flow distribution.

• Character of interface morphology.

• Direct (on-line) diagnosis of defect structure during growth.

• Indirect (off-line) wafer characterization of microscopic and

macroscopic defects as to location and electrical activity.

2. Is characterization of sub-micron particles important in very large

scale integrated (VLSI) electronic technology?

• Yes, to monitor and control the environment, raw material chemicals,

and the product.

3. What key items require monitoring and control in thin film deposition?

• Suitability of the substrate and continuous monitoring of

composition and structure, with initial stages of deposition most

critical.

• In gas phase deposition (CVD) and plasma methods, three dimensional

mapping of gas phase composition is required.

il. What needs to be sensed during materials removal processes?

• Plasma etching requires determination of local electric fields.

• All removal methods require enhanced end point determination and

residual surface analysis.

See Appendix A, page 23, for discussion leader’s summary.

7
SENSOR NEEDS FOR OPTICAL MATERIALS

Discussion Leader; David H. Smithgall, AT&T Bell Laboratories

This group limited their discussion to optical material as defined by "that

which is associated with the transmission, guiding, storage or generation

of light energy, e.g., wavelength of 0.2 - 10 ym." They reached a number

of specific and useful conclusions.

1 . What are the important optical properties that have to be considered

and controlled during processing?

• For conventional optics: image and surface quality, aspheric shape

and refractional index gradients.

• For waveguide optics; geometry, refractive index profiles,

attenuation, dispersion and nonlinear effects at high power levels.

• For electro-optical devices and optical storage devices: geometry,

refractive indices, birefringence and the nonlinear effects of

elasto-optic and magneto-optic coefficients.

• Process control for the fabrication of light guide fibers and

electro-optical devices required similar accuracies.

• The fabrication of multiple quantum well structures requires evaluation and control with resolutions on the order of 10 angstroms.

2. What are the future directions in optical materials?

• Large scale optics where the fabrication requirements are those of

conventional optics, scaled to large sizes coupled with the control

aspects of adaptive optics.

• Another future direction is very small scale optical structures,

driven by integrated optics and semiconductor VLSI programs.

• The geometry requirements for very small scale components include

measurement of deposited layer thickness, device feature dimensions,

and in the case of soot processes, particle size.

• Materials composition concerns for very small scale comprise

refractive index profiles and homogeneity.

• Process parameters required for very small scale; gas flow rates,

concentrations and temperatures of precursors.

See Appendix A, page 25, for discussion leader’s summary.

8
SENSOR NEEDS FOR METALS

Discussion Leader; Phillip Parrish, Defense Advanced Research Projects

Agency

The discussion group selected two model systems, ingot melting and heat

treatment, to illustrate key sensor needs. They identified a number of

important sensor needs that are generic to wide segments of the metal

processing industry.

1. What are the broad classes of metal processing?

• Melt processing (atomization, ingot, castings/single crystals).

• Solid state transformation processing (heat treatment, diffusion

bonding)

• Thermomechanical processing (hot isostatic pressing, ingot

conversion, forging, extrusion).

2. Having selected two basic types of metal processes, ingot melting and

heat treatment as model systems, what are their important sensor

requirements?

Generic Sensor Requirements

• Ingot Melt Processing

Melt temperature

Interfacial (solid/liquid) temperature

distribution

Interface location and shape (3~D)

Melt chemistry (and distribution)

Melt inclusions (from unmelted refractory

metals, ceramic contaminants)

Melt vapor chemistry

Type of Process

VAR

E-beam

Plasma

Ingot,

Ingot,

Ingot,

ingot methods

castings

castings

castings

E-beam, plasma hearth

melting ; (also, coatings)

• Heat Treatment

Inspection of primary phases

Grain size and growth

Recrystallization

Features of second phases

Size

Distribution

Volume fraction

Nature, e.g., coherent or incoherent

State of residual stress

Heat treatment for

conditioning prior to

deformation processing.

Heat treatment for

precipitation hardening.

Final heat treatment

See Appendix A, page 27, for discussion leader’s summary.

9
SENSOR NEEDS FOR CERAMICS

Discussion Leader: Fred F. Lange, Rockwell International Science Center

This group limited their discussion to powder processing methods which

generally included the following major steps: powder manufacture, preparation of powder for consolidation, consolidation (making shape), sintering

( densif Icat ion and microstructural development) , and post-densif ication

treatments (machining, heat treatments, etc.). The group selected several

important areas of need for sensor applications in ceramic processing.

1 . What is the current status of sensor applications for ceramic

processing?

• Difficult to judge due to proprietary nature.

• In-line sensors are used to a higher degree in the manufacture of

ceramics for electronic packaging.

• Powders are characterized only occasionally on a batch to batch

basis.

2. What are the important areas of sensor needs for ceramic processing?

• Content, size and homogeneity of phases in powders.

• Rheology (viscosity, shear rate sensitivity, etc.) of slurries and

deformable powder /polymer mixtures during consolidation/forming.

• Monitoring organic extraction.

• Void phase in consolidated powder compacts (average density of

compact, density distribution).

• Adherence of ceramic coatings on metals and other ceramics.

• Thermal profiling of the furnace and the powder compacts during

sintering is desirable.

• Monitoring tool wear, surface damage, and grinding forces during

machining of densified ceramics would be desirable.

See Appendix A, page 29, for discussion leader’s summary.

10
SENSOR NEEDS FOR POLYMERS

Discussion Leader: Witold Brostow, Drexel University

This group discussed a large array of general topics which included sensor

techniques; polymerization; processing with real time on-line control com- puter modeling and simulation; and processors, computers, and expert systems. The group reached some general conclusions.

1 . Which type of sensor has the highest potential for control of

polymerization?

• Fiber optic based sensors.

2. For polymer processing which sensor should be given priority?

• Reflective spectroscopy.

See Appendix A, page 33» for discussion leader’s summary.

11
SENSOR NEEDS FOR BASIC MATERIALS

Discussion Leader: William Dennis, American Iron and Steel Institute

This discussion group took a broad view of sensor needs for basic materials

processing rather than focus on actual sensor requirements and reached

several conclusions: (1) the development of process control sensors that

the industry could afford to use is highly desirable, (2) since sensors for

basic Industries tend to be more difficult to develop and resources more

limited, collaborative approaches to R&D are mandatory, and (3) the desirability of the National Bureau of Standards expanding its role already developed for steel and aluminum to facilitate systematic surveys of domestic

needs and overseas sensor technology.

See Appendix A, page 35, for discussion leader's summary.

12
SENSOR NEEDS FOR COMPOSITES

Discussion Leader: Richard S. Williams, United Technologies Research

Center

Initial discussions centered on broad issues concerning intelligent

materials processing. The conclusion reached was that the R&D approach to

automated materials processing must be truly interdisciplinary including

materials and process modeling, sensors and measurement science, artificial

intelligence and process control, and engineering design. The group also

come to some important and specific conclusions concerning sensor needs for

composites.

1 . What are the sensor requirements for assembly and lay-up of polymer

matrix composites?

• Measurement of incoming constituent material properties: tackiness

of prepreg, extent of aging of the matrix, impurities, composition,

voids/inclusions /defects.

• Tactile sensing for automated lay-up and assembly.

• Metrology to control positioning accuracy.

• Fiber orientation.

• Fiber volume fraction in the prepreg.

2. What are the sensor requirements for composite processing during

constituent consolidation?

Priority for Development

Need to Sense

Polymer

Matrix

Ceramic

Matrix

Metal

Matrix

Porosity /voids /Indus ions high high high

Interfacial bonding medium high high

Matrix properties (Tg, viscosity, etc.) high medium high

Residual stress low medium medium

Fiber geometry low med ium medium

Microstructure (fiber and matrix) low/high* medium high

*NOTE: Low for thermosetting polymers and high for thermoplastic polymers.

See Appendix A, page 37, for discussion leader’s summary.

13
SENSOR METHODOLOGIES FOR PROCESS PARAMETERS

Discussion Leader: Robert H. Bullis, United Technologies Research Center

The discussion group made a number of general observations. The sensor

community, in general, is not aware of the needs of the advanced materials

processing community while the materials community lacks a good appreciation of the most recent sensor advances that can favorably impact process

automation. Process modeling is viewed as the key factor which should govern both the overall automation strategy and sensor selection. Specific

applications of established sensing and measuring techniques are required

rather than a significant number of new inventions. The discussion group

also identified several important sensor requirements.

1. V/hat key sensor methodologies are required to determine process

parameters for metals and semiconductors?

• The most important problems are temperature distributions in

the melt, location and shape of the liquid/solid interface, flow

distributions, melt chemistry, and effluent gas composition.

• The most promising approaches are acoustics and optical techniques

such as CARS, laser induced fluorescence, and Raman scattering.

• The question of fluid flow distributions in metals and

semiconductors remains an open issue.

2. What are the other key sensor methodologies that look promising for

process parameters?

• Miniaturized microelectronic and fiber optic sensors for the

measurement of pressure, temperature, fluid flow and gas composition

process parameters and for the measurement of cure conditions in

composites.

• Ultrasonics for mechanical properties and grain size determinations.

• The scanning tunneling microscope for nucleation, wetting, and film

growth thickness in electronic materials.

• Developing techniques on fluid flow analysis for application to

crystal growth and electroplating.

• Many approaches offer potential for thickness measurements of metal

coatings including acoustics, x-ray back scattering and electrostatics.

See Appendix A, page 39, for discussion leader’s summary.

14
SENSOR METHODOLOGIES FOR DIMENSIONAL METROLOGY

Discussion Leader: E. Clayton Teague, National Bureau of Standards

The group discussed the broad range of dimensional metrology applications

in advanced materials processing within the industries related to conventional structural materials and materials removal processes such as machining, ceramics processing, and semiconductor processing. Scales of

measurement range from nanometers to tens of meters; environments range

from superb laboratory conditions of the semiconductor class 10 and class

1 clean rooms to the hostile manufacturing conditions of a steel rolling

mill; times allowed for a measurement range from the micro and milliseconds

for an adaptive control sensor to the static times required for a precise

determination of the dimensions of a mold for composite material aerospace

components. Participants in this session selected from this broad range of

applications those areas of dimensional metrology which they saw as being

most important and generic for national needs.

1. What are examples of important national needs for dimensionally -based

measurements to achieve adaptive control of process parameters?

• Date reductions techniques are required to reduce the large

quantities of information obtained with modern sensor and computer

technology to the relatively small amount of digested information

needed for controlling processes.

• Dimensional measurements in support of adaptive control of other

quantities.

• Fast and remote measurements of part displacements and part

dimensions in all ranges of dimensional measurements from small to

large scale.

• The semiconductor industry needs to be able to achieve mechanical

manipulation without introducing particulate contamination into the

processing environment.

2. What is the major need for dimensionally-based measurements to achieve

adaptive control of part properties?

• Small dimensional measurements for the semiconductor industry

involving profiling for features whose dimensions are small compared

to visible light wavelengths.

3. What are examples of important needs for dimensionally-based

measurements to provide process diagnostics?

• Control of particulates in semiconductor processing environments and

in all materials used in fabrication processes.

15
What are some possible technical solutions to developing the needed

sensor methodologies?

• Modulated scanning laser systems, holography, phase-conjugate

optics, adaptive optics, active optics, acoustic and laser ranging,

combined nonlinear and active optics appear to hold promise.

• Techniques which rely upon differential Information, l.e., those

sensitive to anomalies and defects, the scanning tunneling

microscope, scanning optical microscopy relying upon sensitivity

to depth of focus. Interferometry, etc., also look promising.

5. What work Is needed to develop and apply the new methods In the near future?

• Adapt and adjust available and new sensors to Industrial

environments.

• Develop new techniques for very high accuracy time Interval

measurements to Improve capabilities of ranging and pulse calipertype dimensional measurements.

• Adapt measurement approaches to select desired information,

incorporate as much preprocessing of incoming raw data as possible.

See Appendix A, page 43, for discussion leader’s summary.

16
SENSOR METHODOLOGIES FOR MATERIALS

CHARACTERIZATION (NDE)

Discussion Leader: Bernard R. Tittmann, Rockwell International Science

Center

The discussion group selected and discussed five broad generic sensor needs

for materials characterization during processing. The sensor areas or parameters were selected so as to have as much commonality as possible for

the processes discussed for a wide variety of materials. The group reached

a number of important conclusions.

1 . What are the generic sensor requirements for broad classes of materials

processing and what sensor devices look promising?

• Two and three-D temperature profile utilizing ultrasonic velocity

and infrared radiation.

• Shape of solid liquid interface utilizing ultrasonic backscattering,

x-ray tomography, and magnetic flux.

• Microstructure of primary and secondary phases utilizing ultrasonic

attenuation, thermal waves, radiography, eddy currents, and NMR

imaging.

• Rheology including viscosity and shear rate dependence utilizing

shear and longitudinal ultrasonic waves and dielectric techniques.

• Three-D macro-residual stress (not discussed in detail).

2. Is one sensor technique likely to be sufficient to meet these generic

sensor needs?

• No, each sensor methodology should make use of more than one device

for a particular process parameter or material property so that the

concept of a "multi -component sensor" methodology was developed

(e.g., ultrasonics plus eddy currents).

• Since multisensor methodology requires an interdisciplinary

approach, more interdisciplinary graduate training at universities

and a deeper interaction between universities and Industry is

recommended.

See Appendix A, page M7, for discussion leader's summary.

17
SENSOR METHODOLOGIES FOR SURFACE PROPERTIES

Discussion Leader: L. Duane Dxmlap, Aluminum Company of America

The discussion was divided into two principal categories: (1) the detection,

processing, and classification of surface defects; and (2) the measurement

of surface characteristics critical to process control. In each category

interest was expressed solely for non-contacting forms of measurement.

Several important sensor needs were identified.

1. Progress is being made in the development of on-line sensor systems to

detect defects on the surface of materials moving at high speeds.

However, much work remains to develop image processing algorithms and

techniques to identify and categorize defects for statistical control

of the process.

2. What are the key surface characteristics that need to be determined by

accurate, real-time, non-contacting measurement?

• Temperature.

• Residual stress.

• Surface roughness (topography) and flatness.

• Thin film thickness.

• Surface chemistry.

3. Why can't measurements of surface properties be made accurately today?

• There is a lack of understanding of the many surface parameters and

their inter-relationships and of the effect upon sensor response.

4. What steps can be taken to improve the accuracy and functioning of

remote sensors for surface properties?

• Actively promote programs that increase fundamental understanding of

critical surface parameters and rally key universities, technical

societies, and industries around this effort.

• Develop mathematical models relating variables such as electromagnetic reflectivity, surface roughness and topography,

emissivity, etc.

See Appendix A, page 51, for discussion leader's summary.

18
SENSOR METHODOLOGIES FOR ADHESION AND INTERFACES

Discussion Leader: Haydn N. G. Wadley, National Bureau of Standards

The group developed working definitions of adhesion and interface properties,

established a priority order list of sensor needs, and reviewed the present

status of sensor R&D.

1. What adhesion and interface properties should be measured?

• The work to separate an interface less the energy of the two

surfaces is a measure of interface adhesion.

• The adhesion and physical and chemical properties of interfaces need

to be measured together with the characterization of phases and

defects that may be present in the interface region.

• Measurements ideally should be capable of being made on a single

interface (e.g., weld or adhesive bond), distributed interfaces

(e.g., matrix-reinforcement interfaces in composites, grain

boundaries and second phase-matrix interfaces in metals), and

spatially delocalized interfaces (e.g., liquid-solid interface of

alloys with broad "mushy" zones).

2. Are adhesion and interfaces important during materials processing? If

so, what systems are most important? How are they presently measured?

• Adhesion and interface properties are vital components in

determining the performance of a material. It is essential that

sensors be developed for their measurement during materials

processing.

• Reinforcement-matrix interface and adhesive bond strength are two

very important systems where sensors are needed.

• Sensors are also needed to measure properties in other important

systems including solidification interfaces and grain boundaries.

• Very few techniques exist today for these measurements and none are

in the form of process control sensors.

3. What physical phenomena might be available to form the basis of sensor

measurement methodologies?

• Ultrasound can be used to observe quantities such as modulus,

density, and temperature (at low frequencies).

• At higher frequencies, ultrasonic scattering from grain and elastic

inhomogeneities promises nondestructive microstructure

character ization.

19
• Interface elastic waves appear promising for characterizing

interfaces.

• X-rays, dielectric measurements, NMR, eddy currents, etc. also hold

promise.

• A premium is to be attached to techniques that provide spatially

resolved information via tomography, synthetic aperture, etc.

• Three-dimensional mapping of internal friction might be used to

characterize interfaces.

• Embedded fiber optics can be applied to interfaces.

• Fluorescent dyes, dielectric properties, and shear modulus can monitor epoxy cure for adhesion and composites.

4. In priority order, what are the sensor needs?

• We really do not know thp answer yet!

• Adhesion might be related to physical mapping of surface condition,

contamination, curing (molecular properties), adhesive thickness,

porosity, and disbonds.

• Interfaces might be related to topology, temperature distribution,

modules (bulk and local), and residual stress.

See Appendix A, page 53. for discussion leader's summary.

20
APPENDIX A

WORKSHOP REPORTS

WORKSHOP REPORT ON SENSOR NEEDS FOR PROCESSING

TECHNOLOGIES: ELECTRONIC MATERIALS

L. Eric Cross

Pennsylvania State University

1. Consideration was confined to semiconductor materials, silicon, GaAs,

CdTe, etc.

2. Bulk crystal growth.

All techniques which go from liquid to solid state need sensors for:

a) Three dimensional temperature distribution in real time possibly

optical or ultrasonic methods.

b) Three dimensional fluid flow distribution possibly using ultrasonic

techniques.

c) Techniques for the direct determination of interface morphology.

No direct method appears to exist for diagnosis of defect structure during

growth

Indirect character izat ion of wafers is currently essential.

Measurements needed are of microscopic and macroscopic defects, dislocation,

etc., giving both location and electrical activity.

A rapid nondestructive evaluation is required such as IR imaging or recombination measurement. Currently, these techniques are used in the laboratory but not in production facilities.

3. With decreasing scales imposed by VLSI, techniques are required for

characterizing sub-micron particles both in the environment and as contaminants in raw material chemicals.

Light scattering offers a possible technique but probably multisensor

approaches will be required to cover the dimensions of interest.

4. For all thin film deposition methods, the initial stages of deposition

appear most critical. It is important to be able to define the suitability

of the substrate for deposition and to be able to monitor continually at

low coverage.

Optical methods and scanning differential microscopy offer possibilities

for monitoring surfaces and deposition.

Composition and structure must also be determined and LEED together with

surface enhanced optical methods can be used for this purpose.

In gas phase deposition (CVD) and plasma methods, composition in the gas

phase as a function of position (spacial coordinates) is required.

23
5. For material removal, plasma etching requires measurement of local

electric fields. All methods would benefit from enhanced end-point

determination and residual surface analysis as is possible in the

laboratory using laser interferometric techniques.

General Observations

1. Sensing is only one part of measurement science and in general needs

reinforcement.

2. The approach to automated materials processing requires interdisciplinary

skills and there is need of interaction of university and industry to make

university faculty aware of the problems.

3. As a Nation, America appears particularly strong in individual

initiative enterprise and innovation, but weak in quick collective

exploitation of this advantage in its application to manufacturing.
WORKSHOP REPORT ON SENSOR NEEDS FOR PROCESSING

TECHNOLOGIES: OPTICAL MATERIALS

D. H. Smithgall

AT&T Bell Laboratories

Optical material is defined as that which is associated with the

transmission, guiding, storage or generation of light energy, e.g., wavelengths of 0.2 - 10 ym. Typical examples are amorphous (glass) materials

such as oxides, fluorides, calcogenides and polymers, and crystalline

materials such as sapphire, lithium niobate, and gallium arsenide.

For conventional optics, the properties of image and surface quality,

aspheric shape and refractive index gradients are important. For waveguide

optics, the geometry, refractive index profiles, attenuation, dispersion

and certain nonlinear effects at high power levels are important. For

electro-optic devices and optical storage devices, the important factors

include geometry, refractive indices, birefringence and the nonlinear

effects of elasto-optic, magneto-optic, and electro-optic coefficients.

The process for the fabrication of lightguide fibers was discussed as an example of the fabrication of one class of these materials. The accuracies

and tolerances typical of this technology also were representative of those

required for the fabrication of electro-optic devices. Process control

requires nondestructive, non-contact, high speed and robust sensors. Discussion then shifted to the requirements for electro-optic devices and, in

particular, the fabrication of multiple quantum well structures. Evaluation

of these structures required resolutions on the order of 10 angstroms.

As a result of the group's discussion, it was determined that there are two

directions for future work in optical materials. The first is towards the

fabrication of very large scale optics, driven by the SDI program and other

astronomical programs. While radar systems employ wavelengths in the millimeter range, many of the fabrication techniques for producing large re- flecting surfaces are similar to those for materials used at optical wavelengths. The fabrication requirements are those of conventional optics,

scaled to large sizes, coupled with the control aspects of adaptive optics.

The second direction is towards very small scale optical structures, driven

by integrated optics and semiconductor VLSI programs. Within this arena,

there are two general areas which require measurement: geometry and

materials composition.

The geometry requirements include measurement of deposited layer thickness,

device feature dimensions and, in the case of soot processes, particle

size.

In the extreme of monolayer deposition for quantum well structures, measurement resolutions on the order of 1 - 2 atomic layers are desired. For feature measurements, resolutions of 0.01 ym - 0.1 ym will suffice.

25
Materials composition concerns comprise refractive index profiles and

homogeneity with resolutions on the order of .001? - .1?.

A related concern is the measurement of process parameters, in particular,

accurate measurement (.01? - .1?) of gas flow rates, concentrations and

temperatures of precursors, and of the process environment. In addition,

the purity of the precursors is an Important concern.

Finally, it is necessary to know what macroscopic measurements of any

quantity adequately predict the average microscopic properties of the

final product. This means, for instance, that the measurement of precursor

reactant chemical concentration can result, under the proper processing

conditions, in the uniformity of characteristics in the final product.

26
WORKSHOP REPORT ON SENSOR NEEDS FOR

PROCESSING TECHNOLOGIES: METALS

Phillip A. Parrish

Defense Advanced Research Projects Agency

Goal

Identify some key sensor needs relevant to the control of metals processing.

Approach taken

Broad categorization of classes of metals processes; determination of key

intrinsic and extrinsic features which require sensors.

A. Classes of Metals Processing

Class I: Melt Processing

- Atomization

- Ingot

- VIM

- VAR

- E-beam special hearth methods

- Plasma; requiring additional control

- Castings/single crystals

Class II: Solid State Transformation Processing

- Heat treatment

- Diffusion bonding

Class III: Thermomechanical Processing

- Hot isostatic pressing

- Ingot conversion

- Forging

- Extrusion

In order to derive the specific sensors required to monitor processes and

offer opportunities for active control of processes based upon sensor input

and process models, one must determine the critical intrinsic features of

the materials being processed, which can be related to desired properties.

Thus, sensor readings to be attained can be related to property limit ranges

which are acceptable for the finished material. Through the process model,

these sensor readings can be related to extrinsic processing parameters

which are utilized for control (temperature, pressure, feed rate, draw

ratio , etc . )

B. Process Sensor Requirements

The group attempted, in the short period available, to determine several

important sensor requirements for two basic types of metals processes,

ingot melting and heat treatment. The results are tabulated as follows:

27
Ingot Melt Processing

Generic Sensor Requirements

Melt temperature

Interfacial (solid/liquid) temperature

distribution

Interface location and shape (3"D)

Melt chemistry (and distribution)

Melt inclusions (from unmelted refractory

metals, ceramic contaminants)

Melt vapor chemistry

Heat Treatment

Generic Sensor Requirements

Inspection of primary phases

Grain size and growth

Recrystallization

Type of Process

ingot methods

VAR

E-beam

Plasma

Ingot castings

Ingot, castings

Ingot, castings

Important for E-beam,

plasma hearth melting;

(also, coatings)

Type of Process

Heat treatment for

conditioning prior to

deformation processing.

Features of second phases

Size

Distribution

Volume fraction

Nature, e.g., coherent or incoherent

Heat treatment for

precipitation hardening.

State of stress Heat treatment after

Residual machining.

In a similar fashion, it is possible to develop sensor requirements for any

of the other classes of metals processing.

It is important to realize the iterative nature of sensor —process model

control needs. As new sensors become available, process models may be

tested and improved, which will lead to new sensor requirements. The control system will evolve and become more sophisticated both as computational

capabilities improve and as sensors and models become more quantitative in

their description of the desired process.

28
WORKSHOP REPORT ON SENSOR NEEDS FOR

PROCESSING TECHNOLOGIES: CERAMICS

Fred F. Lange

Rockwell International Science Center

Discussion included the major topics: current status (where are we?),

priorities for sensor needs, and forum for cooperation.

Commonality of Ceramic Processing

A majority of ceramics made for electronics, wear, and structural applications

are processed from powders that are consolidated into shapes and densified

at elevated temperatures to eliminate voids and to develop the desired

property controlling microstructure. Therefore, discussion was limited

to powder processing methods which generally include the following major

steps

Powder manufacture

Preparation of powder for consolidation

Consolidation (making shape)

Sintering ( densif ication and microstructural development)

Post-densif ication treatments (machining, heat treatments, etc.)

The appendix lists sub-steps and major characteristics/parameters that

require control.

Current Status

The current use of sensors for on-line processing is difficult to judge due

to its proprietary nature. It is generally accepted that on-line sensors

are used to a higher degree in the manufacture of ceramics for electronic

packaging (substrates, IC carriers, multilayer circuit boards, etc.); but

it was also stated that powders, which initiate the processing, are only

characterized on occasional batch to batch basis.

It was generally agreed that the concept of sensors and process control is

less viable without correct control of starting powders. In the United

States few ceramic manufacturers make their own powders, i.e., with the

exception of several manufactures of silicon carbide and silicon nitride

products, powder manufacture is not an integral part of ceramic processing.

Powders are generally bought from the chemical or basic materials industry

(e.g., alumina from aluminum manufacturers). In recent years, foreign

chemical manufacturers, driven to diversify by higher raw materials costs

and rising third world competition, have become powder suppliers for

advanced ceramics. At the same time, they are developing strong capabilities to manufacture advanced ceramic components. It is not unreasonable to

suspect that with the need to control all processing steps to achieve re- liability, advanced ceramics can become a branch of the chemical industry.

29
It was also concluded that our stronger foreign competitors have spent a greater effort in developing empirical process models, a key parameter in

their competitive edge that could be overwhelming if they adapt greater

in-line control of their empirical models.

Sensor Needs

The discussion group suggested seven areas where sensors could make an Impact coupled with known process models.

1. Content, Size, and Homogeneity of Phases: Powders prepared for

consolidation can be a mixture of different powders (inorganic additives

for densif ication and second phases used to develop microstructure and

properties) and different organics (added to impart flow properties for

consolidation). Reasons for knowing the content of constituent phases are self evident. Knowledge of particle (crystallite and agglomerate) size of

the powder(s) is important for the densif ication kinetics and control of

flaw size population, e.g., strength (where maximum extreme values are critical) ; organic inclusions (again, extreme values are critical) produce

voids during densif ication. Homogeneity of the inorganic phases is important for densif ication, microstructure, and properties. Homogeneity of the

organic phases is important for the rheology of consolidation.

2. Flaw Characteristics of Slurries and Deformable Powder/Polymer Mixtures

Ceramic powders are consolidated into shapes by different methods. Some of

the important consolidation methods involve either slurries (e.g., tape

casting of substrates, slip casting, etc.) or deformable powder /polymer

mixtures (e.g., injection molding, extrusion, etc.). Rheology (viscosity,

shear rate sensitivity, etc.) is critical to these consolidation/forming

methods.

3. Monitoring Organic Extraction: Organic binders are involved in almost

all consolidation methods. These organics must be slowly removed at low

temperatures without disrupting the powder compact. Sensors are required

to monitor the extraction of these polymers.

4. Void Phase in Consolidated Powder Compact (Average Density of Compact,

Density Distribution): The bulk density of a powder compact controls

densif ication temperature and kinetics (which, in turn, control microstructure and properties). Gradients in bulk density result in a shape

change (shrinkage during densif ication is proportional to initial bulk

density) . Isolated regions of different bulk density shrink more or less

than their surroundings, producing stresses during densif ication, resulting

in the formation of crack-like voids detrimental for both electrical and

structural properties.

5. Coating Adherence: Ceramic coatings are applied to both metals (e.g.,

for thermal protection) and other ceramics (electronic applications) as powder slurries (thick films), metal-organic compounds (thin films), and

flame sprayed coating. Defects at the coating/substrate interface which

might grow during heat treatment ( densif ication) , causing coating

separation, should be identified.

30
6. Thermal Profile: Thermal gradients exist in the furnaces used to

densify the powder compacts; these gradients depend on the furnace, the

fixtures used to place the compacts, and the mass of the compacts themselves. Thermal gradients in the compacts will lead to differential

shrinkage during sintering, stresses that can lead to disruptive processes,

and shape changes. Thermal profiling of the furnace and the components

themselves would be desirable.

7. Machining Operations: Ceramics for wear and structural applications

usually require diamond machining after densif icat ion. Monitoring tool

wear, surface damage, and grinding forces would be desirable.

Form for Cooperative Utilization of R&D

The pros and cons of a national center for ceramic processing, co-sponsored

by government and industry, was the major focus of discussion. It was questioned whether larger, established corporations would take part in such a consortium (proprietary aspects) but agreed that less capitalized companies

would, if the center were a well-equipped user facility (different processing

technologies and a knowledgeable technical staff) . Evaluation of sensor

technology would be one aspect of the center.

APPENDIX —Outline of Major Processing Steps

Powder Manufacture

Important Powder Characteristics

Crystallite size

Agglomerate size

Agglomerate strength

Impurities, type and amount

Inclusions, inorganic and organic

Phase distribution

Preparation for Consolidation

Mixing of

Surfactant

Sintering aid

Second phases

Organics

Spray drying (dry pressing consolidation methods)

Conso 1 idat ion /Forming

Sub-division of methods:

Dry pressing

Uniaxial

Iso-pressing

Slurry

Injection molding

Tape casting

Slip casting

Extrusion

31
Denaif icat ion

Important parameters

Dimension

Density

Weight changes

Volatile organics

Volatile inorganics

Phase development (reactions)

Void phase

Density

Pores size, distribution, extreme values

Grain size

Distribution

Extreme values

Other microstructural features

Second phases-location, size

Surface features

32
WORKSHOP REPORT OF SENSOR NEEDS FOR

PROCESSING TECHNOLOGIES: POLYMERS

Witold Brostow

Drexel University

Discussion at the Polymer Workshop covered a large array of topics,

including: sensor techniques, available as well as potentially usable in

the future; polymerization, in particular, sampling problems; processing

with real time on-line control, if possible; computer modeling and simulation, both for processing and for determination of mechanical and thermophysical properties of manufactured materials; processors, computers and

expert systems; international information flow; product characterization;

and process integration.

The discussion led at least to one new term, that is of a near-to-line

determination procedure. In the following Recommendations, 1 and 2 are

specific to polymer manufacture, while the remaining ones are general.

Recommendations

1 . Control of polymerization requires knowledge of a number of parameters.

Fiber optics have high potential as technique for furnishing several,

rather than just one, pertinent parameters.

2. Polymer processing involves also controlling a number of parameters.

In development of techniques for this area reflective spectroscopy should

be given priority.

3. In case of characteristics which inherently cannot be determined,

on-line and near-to-line determination procedures have to be developed. We

define the latter procedures as providing data in a time so short that

feedback to, and substantially affecting, the ongoing process is possible.

Scanning of a plastic pipe surface for crazes and cracks during an extrusion is a simple example.

4. We can hardly afford repetitions of cases when developments abroad have

taken American engineers and scientists by surprise. In addition to obviously better scanning of and publishing in international literature, we recommend more attention and more funds for international research projects . At the same time, flow of information across our borders, inside as well as outside of such projects, must be precisely controlled by American

researchers.

5. Not only a specific process but materials management in the plant, in

fact, the entire plant operation, should be optimized first ; then optimizing the process, or processes, will produce a much better overall

result

33
6. General Strategy of Process Control , which in each case should be

implemented as close as possible to the following plan.

(a) Develop a model of the process first, using existing theoretical

knowledge and/or computer simulations.

(b) From the results of stage (a), define types and locations of

necessary sensors. Develop and install the sensors.

(c) From stages (a) and (b), develop an expert system to run the

process.

(d) Don't forget to run the process to see whether it is

what was wanted.

34
WORKSHOP REPORT ON SENSOR NEEDS FOR

PROCESSING TECHNOLOGIES: BASIC MATERIALS

William Dennis

American Iron and Steel Institute

1. To what extent have the sensor needs of the basic industries, other

than steel, been documented?

With the exception of the aluminum industry, which is currently reviewing

its sensor needs with respect to temperature measurements and surface

inspection, only the steel industry has completed a detailed survey.

Other basic industries recognize the critical importance of collaborative

action in this high cost-high risk area, but appropriate action has been

hindered by perceived problems of confidentiality.

To overcome these traditional institutional barriers it was agreed that a questionnaire should be designed and issued by an acceptable "honest broker"

and that the National Bureau of Standards might be an appropriate agency

for this purpose. To succeed, it was considered that a committee of

experts from the basic industries should advise on the documentation and

the addresses for this survey.

2. Are any of these "generic needs" found in several processes or industries?

Although specific, sensor designs will be required to meet specific end-use

situations. It was agreed that the research and development required to

facilitate sensor design would be substantially generic both in regard to

different processes and industries.

Here again, the initial step must be a broad survey of sensor needs which

can then be analyzed to determine the extent to which the developments

required will be generic.

3. What are the key sources required for sensor research and development

and how can they more efficiently be harnessed to the task?

Key resources were seen to include: (a) small business entrepreneurs,

(b) academic research, (c) national laboratories, and (d) basic industrial

science contributing to multidisciplinary programs. To bring these various

elements together and to motivate appropriate actions, it was considered

necessary to develop an industry (or better still a multi-industry)

focus on the primary sensor needs and the nature of the end use and its

environment.

Finally, it was agreed that the preparation of case studies on successful

and unsuccessful industrial sensor projects could be worthwhile.

35
To what degree is technology transfer in this area being managed

efficiently and how might it be improved?

As no one has this responsibility, basic materials technology transfer is

somewhat haphazard, especially in respect to overseas technology on sensors.

To accelerate progress and to efficiently utilize the high cost resources

required, it was considered that a central clearing house would be

desirable. Here again, it was suggested that the National Bureau of

Standards might be an appropriate agency.

Conclusion

For the basic material industries to regain their competitive ability in

world markets, the development of process control sensors, which they can afford to install , is highly desirable, although there are obviously many

other problems, technical and non-technical, which need to be addressed.

As the sensor needs for these mature industries are frequently more

difficult to develop than those required for the new material processes, and

as the resources available are severely limited, a collaborative approach to

the basic research and development becomes mandatory.

To provide a common ground on which these industries can come together to

review, analyze, and act on these needs, it is suggested that the National

Bureau of Standards might enlarge on the role which it has already

developed in respect to steel and aluminum. Facilitating systematic

surveys of overseas sensor technology, with mult i -industry participation,

might be an important part of this role!

36
WORKSHOP REPORT ON SENSOR NEEDS FOR

PROCESSING TECHNOLOGIES: COMPOSITES

Richard S. Williams

United Technologies Research Center

The discussion group on Sensor Needs for Composites Processing met Monday,

December 16, 1985. Initial discussions centered on global issues concerning "intelligent materials processing" (IMP) and the scope and goals of the

forum. The following comments summarize these discussions.

1 . There is a growing trend within the U.S. and abroad to integrate

inspection, process control, and manufacturing operations. The goals are

to increase product quality, productivity, and profitability by making the

part right, the first time and every time, and by eliminating separate

inspections and rework which add no value to the product. Further, there

is an urgent need for increased R&D in manufacturing science to develop

this technology.

2. The prestige, relevance, and importance of manufacturing science R&D

needs to be raised with industry, government, and academia.

3. A thorough assessment of sensor needs for any given application cannot

be accomplished without the knowledge of the processing mechanisms, the

approach for control, and the end use of the product. The conclusion

reached was that the R&D approach to IMP must be truly interdisciplinary

including materials and process modeling, sensors and measurement science,

artificial intelligence and process control, and engineering design.

The discussions of the technical requirements for sensors for composites

processing was initially quite circumspect. Composite materials, by definition, encompass a wide and diverse range of material constituents and

associated processing technologies. The sensor requirements vary from one

type of composite materials system to another. Therefore, it was decided

by the group to categorize sensor requirements based on the type of matrix

materials: polymer, metal, or ceramic. Further, composites manufacturing

is usually accomplished via several separate and distinct operations:

fabrication and processing of the constituent materials; assembly and layup of the constituent materials; and finally, consolidation of the constituent materials. The consensus of the group was not to address constituent

materials fabrication and processing; discussion was limited to the assembly and lay-up of the constituent materials in polymer matrix composites;

and to the consolidation processing needs for all three matrix categories.

Table I summarizes the sensor requirements for assembly and lay-up of polymer

matrix composites. Further, since the properties of the constituents

affect these and subsequent operations, these requirements are also listed.

The consolidation processing requirements for polymer, ceramic, and metal

matrix composites are summarized in Table II. These needs are also listed

as high, medium, and low priority.

37
TABLE I

Sensor Requirements for Assembly and Lay-up of Polymer Matrix Composites

o Measurement of incoming constituent material properties:

Tackiness of prepreg

Extent of aging of the matrix

Impurities

Composition

Vo i ds / i nc lus i ons /de fec t s

o Tactile sensing for automated lay-up and assembly

o Metrology to control positioning accuracy

o Fiber orientation

o Fiber volume fraction in the prepreg

TABLE II

Sensor Requirements for Composite Processing

During Constituent Consolidation

Priority for Development

Need to Sense

Polymer

Matrix

Ceramic

Matrix

Metal

Matrix

Porosity /voids /inclusions high high high

Interfacial bonding medium high high

Matrix properties (Tg, viscosity, etc.) high medium high

Residual stress low medium medium

Fiber geometry low medium medium

Microstructure (fiber and matrix) low/high^ medium high

NOTE: Low for thermosetting polymers and high for thermoplastic polymers.

38
WORKSHOP REPORT ON SENSOR

METHODOLOGIES: PROCESS PARAMETERS

Robert H. Bullis

United Technologies Research Center

General Observations

From the presentations and workshop at the Forum, the technical challenges

associated with developing automated materials processing techniques are

formidable. Equally significant are the rewards to be achieved on a national scale. It is clear the traditional approach of relying on scientific meetings to stimulate developments in this area is not providing the

level of interchange required to ensure a successful program. The sensor

community, in general, is not aware of the needs of the advanced materials

processing community. On the other hand, the materials community lacks a good appreciation of the most recent sensor advances that can favorably

impact process automation. Since future national security is at issue, it

is important on a national level to provide the stimulus to clearly focus

industry and academia on the key technical issues.

It is the general feeling of the technical community at the Process

Parameters Workshop that all too often too much emphasis is placed on the

development of novel sensors and/or measurement approaches without a clear

appreciation of the key parameters governing a specific process. Process

modeling is viewed as the key factor which should govern both the overall

automation strategy and sensor selection. The development of process models must be viewed as an iterative process which is continually upgraded,

redefined, and expanded as new information becomes available. A very significant point made at the Forum was that some processes as they are presently constituted may not lend themselves to a high level of automation.

In this situation modeling activities can potentially reveal new directions

and approaches to achieve desired objectives. A second observation which

is universally true is that the key parameters of the process should be

measured directly, if possible, rather than be inferred from a collection

of secondary measurements. Lastly, broad or system level solutions must be

developed. In this context, the sensor should only be viewed as a tool to

achieve the necessary end.

A host of very elegant measuring techniques are continually being developed

in the laboratory. The real key to being able to take advantage of these

developments is to be able to reduce laboratory concepts to simple real

time measurements providing data of high reliability. Lack of real time

data acquisition severely, if not completely, reduces the value of any

measuring technique, in general, and most profoundly in any automated

industrial controls application. Secondly, in a host of process applications non-intrusive measurements are highly desirable if not imperative.

Additionally, the measuring technique must be simple and user friendly as well as being both cost and process effective.

39
Enabling Sensor Technologies

Developments In microelectronics, fiber optics, and optical techniques

(near IR, far IR, and laser analysis and spectroscopy) over the past decade

have been significant. Today, with miniaturized microelectronic sensors,

it is possible to measure pressure, temperature, flow, acceleration, humidity, chemical composition, and cure condition (charge flow transistor) to

extremely high accuracies. Spurring the development of these devices have

been military and aerospace applications which are just coming to fruition.

This same technology can be applied in selected areas of materials process

automation. The potential of microelectronic sensor technology is clearly

demonstrated by the fact that accuracies achieved with many of the latest

generation devices approach levels, heretofore, attainable only with laboratory standards. More importantly, these new sensors are so cost effective

that many throw-away applications have been developed. Similar advantages

are also achieved with fiber optic and optical sensors. The most promising

fiber optic sensors are completely electrically passive at the measurement

location, thereby permitting operation in extremely hostile environments

with high immunity from electrical interference. The fundamental limitation

of many of these devices is determined only by the materials properties of

the optical conduit. A further advantage in many applications is that the

fiber conduit can be buried or embedded internally in the environment to be

measured such as in a composite material. Small fiber size provides still

further advantages. Today, temperature, chemistry and composition, strain

and deformation, fluid level and flow, foam and bubble detectors, and acoustic and ultrasonic sensors are available in a multitude of optical configurations. As with microelectronic sensors a host of these devices have

become highly developed for military and aerospace applications. Lastly, a revolution is also occurring in optical measuring techniques for gas composition, species concentration, and temperature measurements. Most promising of these techniques are coherent antistokes Raman spectroscopy (CARS),

laser induced fluorescence and Raman scattering. Developments in this

field have been significant from a practical application standpoint. For

example, CARS measurements in the past five years have moved from the laboratory into the field with portable systems now being employed to measure

jet engine exhaust gas temperature profiles.

A general recommendation is that more emphasis needs to be placed on the

new sensor technologies available today. Specific applications of these

established sensing and measuring techniques are required rather than a significant number of new inventions. The basic advanced sensing tools are available. It is a question of applying these tools to advanced automation

requirements. Only through a direct dialogue between the sensor development engineer and the materials processing engineer can this be achieved.

Areas To Be Addressed

Metals and Semiconductors; The problems deemed most important are temperature distributions in the melt, location and shape of the liquid/

solid interface, flow distributions, and the chemistry and effluent gas

composition. The most promising approaches to receive first consideration

should be acoustics and optical techniques such as CARS, laser induced

fluorescence and Raman scattering. The questions of fluid flow distributions

in metals and semiconductors remain an open issue.
Mechanical Properties and &*ain Size; The most promising approach in this

area appears to be ultrasonics.

Nucleation—Wetting —Film Growth Thickness: Most exciting was the IBM

report at the Forum on their most recent work with the scanning tunneling

microscope (STM) . This is a technology, the potential of which remains yet

to be fully realized.

Dislocation Density —Point Defects: No approach has been identified.

Crystal Growth and Electroplating: New techniques on fluid flow analysis

being developed at MIT appear to hold promise for further advances in this

area.

Thickness —Metal Coatings: A host of approaches appear to offer potential

in this area including acoustics, x-ray backscatter ing and electrostatics.

Finally, one area noteworthy of consideration was the whole question of

machine monitoring as it applies to process control. This again raises the

initial question of the importance of process modeling to develop the most

cost effective, practical approach to materials process automation.

Summary

Viewed as the key requirement for achieving significant advances in the

automated materials processing arena is the necessity to break the "business

as usual" syndrome between U.S. industry, academia, and government. From

the results of just this Forum, it is clear that significant progress can be

made. The first ingredient is a suitable forum for technical discussion of

problems and potential solutions. Secondly, a focused effort is required

with a true partnership relationship between industry, academia, and government to establish priorities and objectives. Lastly, a highly cooperative venture with regard to funds, people, and facilities is then required

to achieve success on a national scale.

WORKSHOP REPORT ON SENSOR

METHODOLOGIES: DIMENSIONAL METROLOGY

E. Clayton Teague

National Bureau of Standards

There is a broad range of dimensional metrology applications in advanced

materials processing within the industries related to conventional structural materials and material removal processes such as machining, ceramics

processing, and semiconductor processing. Scales of measurement range from

nanometers to tens of meters; environments range from superb laboratory

conditions of the semiconductor class 10 and class 1 clean rooms to the

hostile manufacturing conditions of a steel rolling mill; times allowed for

a measurement range from the micro and milliseconds for an adaptive control

sensor to the static times required for a precise determination of the

dimensions of a mold for composite materials aerospace components. Participants in this session were asked to select from this broad range of

applications those areas of dimensional metrology which they saw as being

most important and generic for national needs. Some of the questions

addressed and conclusions reached by the participants follows:

1. What are examples of important national needs for dimensionally -based

measurements to achieve adaptive control of process parameters?

Four general areas were highlighted by the discussions of this topic.

(1) A great need to explore and evaluate new systems or other techniques,

which would enable one to achieve an appropriate balance between the large

quantities of information, which can now be obtained with modern sensor and

computer technology and that relatively small amount of digested information which is needed for controlling processes. (2) Dimensional measurements in support of adaptive control of other quantities. An example of

this need is that of determining the thickness of steel plates so that time

measurements can be used to deduce the temperature profile within the

plates via the equation, t = D/v^^g, where D = plate thickness, v^^ = average speed of ultrasound propagation, and t = total propagationai time

through the plate. In turn, one has v^^g = 1/D v(z)dz. (3) A need for

fast and remote measurements of part displacements and part dimensions was

also highlighted in all ranges of dimensional measurements from small to

large scale. (k) Several participants from the semiconductor industry

strongly expressed the opinion that a major need of this industry's

processing facilities was to achieve mechanical manipulation without

introducing particulate contamination into the processing environment.

2. What are examples of important national needs for dimensionally-based

measurements to achieve adaptive control of part properties?

While the group discussed very briefly the needs of other industries, such

as the metal-cutting industries, the major need identified by the group

here was in small dimensional measurements for the semiconductor industry.

Here the need is for profiling, i.e., obtaining z(x) or z(x,y), for

features whose dimensions are small compared to visible light wavelengths.

In this dimensional range, there are now no proven techniques available.

43
3. What are examples of important national needs for dimensionally-based

measurements to provide process diagnostics?

Here, the needs of the semiconductor industries seemed most pressing. As the

dimensions of features and device elements have dropped below 1.0 micrometer,

the need to control particulates in the process environment and in all

materials used in the fabrication processes has become critically important

for the industry to obtain reasonable yields. For particles with diameters

less than 1.0 micrometer, many new phenomena concerning their behavior have

been observed. Another requirement is for a reliable means to calibrate

instrumentation. The recent availability of a series of polystyrene sphere

standards from the NBS Office of Standard Reference Materials was noted.

Sphere diameters now available are 0.3, 1.0, 3.0, and 10.0 micrometers.

4. What are some possible technical solutions?

Suggestions from the group were: modulated scanning laser systems,

holography, phase-conjugate optics, adaptive optics, active optics, acoustic and laser ranging, combined nonlinear and active optics, techniques

which rely upon differential information, i.e., those sensitive to anomalies and defects, the scanning tunneling microscope, scanning optical

microscopies relying upon sensitivity to depth of focus, interferometry,

etc.

5.

What work is needed to develop and apply the new methods in the near

future?

(1) Adapt and adjust available and new sensors to be compatible with

industrial environments. (2) Develop new techniques which enable very highaccuracy time-interval measurements to improve capabilities of ranging and

pulse caliper-type dimensional measurements. (3) Adapt measurement approaches

to select desired information and incorporate as much preprocessing of

incoming raw data as possible. (4) A question was raised by semiconductor

industry representatives as to whether there was any way to eliminate small

(less than 1.0 micrometer) particles from the processing materials and

environment. Maybe one will just have to deal with or overcome their

presence.

A significant portion of the group’s discussions centered on the question:

Are there issues of National policy or practice which overshadow these

technical questions? The following are some of the issues raised in a very

lively discussion of this question.

1 . Inappropriate competitiveness among associated industries prevents

cooperative efforts to attack very real and key problems. The present

cooperative program among the steel and aluminum companies for surface

defect measurement offered many the hope that U.S. industry could overcome

this competitiveness under the right circumstances.

2. Competition and lack of coordination among government agencies both in

terms of efforts which are funded externally and undertaken Internally.
3. Lack of critical mass in equipment manufacturers for much of the new

measurement instrumentation and related process equipment. Particular

examples given were manufacturers of clean rooms, submicrometer particle

counters, and adaptive control sensors and associated software.

4. Instability of support for subcontractors and suppliers. All members

of the group were pleased with and in support of the apparent trend toward

more long-term contracts being initiated by both government and private

industry.

5. Our National political culture creates fragmentation, adversarial

approaches to implementation of new technologies and to solving problems in

ongoing technologies, and to overly short-term foci for industrial,

governmental and, often, even university efforts.

6. Solutions to many of our technical problems could be in establishing a strong focal point to direct national action. The group, however, did not

reach a consensus about whether this focus should more properly lie with

government, industry, or university.

7. The conflict between the industrial proprietary interest and the need for

universities to have freedom to publish research results continues to

create much resistance from industry to fund cooperative centers at

universities.

8. Many members of the group said that each industry should follow the

example of the steel and aluminum industries and identify their own specific needs which were most pressing and industry wide.

9. The negative impacts of export control was of great concern to many

group members.

WORKSHOP REPORT ON SENSOR METHODOLOGIES: NDE

FOR MATERIALS CHARACTERIZATION

Bernhard R. Tittmann

Rockwell International Science Center

Summary

After the presentation of a prepared statement by B. R. Tittmann of the

critical issues for in-process sensing, the Workshop selected five generic

sensor concepts with as much commonality as possible for the processes

discussed for the following materials: electronic, optical, metallic,

ceramic, polymeric, basic and composite materials. The generic process

parameters selected were ( 1 ) 3~D temperature profile, (2) shape of solid/

liquid interface, (3) microstructure of primary and secondary phases,

(U) rheology (viscosity, shear rate dependence), and (5) macro-residual

stress. See Table I. Next, a 2-D matrix was developed specifying the

detailed sensor methodology, corresponding to the process parameters

selected. The issues considered were the sensing device, the corresponding

measurement technique, the data inversion algorithm, the current status

(pay-off in two-five years), and future needs for field application (payoff in ten years). Time permitted treatment of only the first four sensor

technologies. See Table II. A general conclusion emerging from these

considerations was that each sensor methodology should make use of more

than one device for a particular process parameter so that the concept of a "multi -component sensor" methodology was developed. The integration of

several techniques into one sensor methodology requires an interdisciplinary approach. This conclusion logically led to consideration of more

interdisciplinary graduate training at universities and the need for a deeper interaction between universities and industry. Two examples of

current approaches cited toward these issues were the Ames Center for NDE

and the Johns Hopkins University Center for NDE. The conclusions were

(1) the importance of recognizing new techniques in NDE, and (2) the need

for large DoD programs and the involvement of universities, government

laboratories and industrial research laboratories in an integrated,

multidisciplinary fashion.
TABLE

I:

MATERIAL

PROCESS

SFEPS

AND

GENERIC

PROCESS

PARAMETERS

48
49

WORKSHOP REPORT ON SENSOR METHODOLOGIES:

SURFACE PROPERTIES

L. Duane Dunlap

Aluminum Company of America

The discussion was directed primarily towards real-time, in-line measurement

of surface properties of various materials during the manufacturing process.

The discussion was divided into two principal categories: (1) the detection,

processing, and classification of surface defects; (2) the measurement of

surface characteristics critical to process control. In each category,

interest was expressed solely for non-contacting forms of measurement.

The work presently being done by Westinghouse and sponsored by the AISI for

the consortium of steel and aluminum companies was, to our knowledge, the

most advanced effort to date in detecting and classifying surface defects.

Successful detection of surface defects at speeds approaching 5000 FPM has

been accomplished with some success; however, great amounts of work remain

to learn how to rapidly process large quantities of data for real-time

feedback. Additionally, considerable effort remains in the development of

algorithms and material standards for defect classification. The AISI

program was considered exemplary and did not need government support to

continue. Other industries should note the success of this program and

possibly develop similar programs.

Most of our discussion time was directed towards measurement of surface

characteristics. Out of these discussions came the need to provide

accurate, real-time, non-contacting measurement of the following:

temperature

flatness and residual stress

surface roughness (topography)

thin film thickness

surface chemistry

The ensuing discussion developed aroiond the question "Why can't we make

these measurements more accurately today?" We answered this question by

stating our lack of londer standing of the many surface parameters and their

interrelationships and knew little of the effect upon sensor performance.

Stated differently, most industries have devoted large amounts of time and

money towards greater understanding of surface properties to improve the

salability of their product. However, substantially less effort has been

devoted towards the understanding of the interaction of physical phenomena

with the surface from ^ sensory standpoint . Rapid growth in the need for

highly automated manufacturing facilities and the corresponding need for

non-contacting sensors have combined to create escalating requirements for

this knowledge.

51
To Improve the accuracy and functionality of remote sensors, our recommendation to COMAT would be —to actively promote programs that Increase fundamental understanding of critical surface parameters and rally key universities, technical societies, and industries around this effort# Mathematical

models relating variables such as electromagnetic reflectivity, surface

roughness and topography, emlssivlty, etc., are essential to the development and deployment of remote sensors. To our knowledge, no universities

and very few industries have active programs in this area. We concluded

our discussion by stating that much could be gained from the collaborative

efforts of universities, industries, and government and felt this avenue

should be diligently pursued.

52
WORKSHOP REPORT ON SENSOR METHODOLOGIES:

ADHESION AND INTERFACES

Haydn N. G. Wad ley

National Bureau of Standards

1. What adhesion and interface properties should be measured?

The work to separate an interface less the energy of the two surfaces is a measure of interface adhesion. The adhesion and physical and chemical

properties of interfaces need to be measured together with the characterization of phases and defects that may be present in the interface region.

These measurements ideally should be capable of being made on a single

interface (e.g., weld or adhesive bond), distributed interfaces (e.g.,

matrix-reinforcement interfaces in composites, grain boundaries and second

phase-matrix interfaces in metals), and spatially delocalized interfaces

(e.g., liquid/solid interface of alloys with broad ’’mushy" zones).

2. Are adhesion and interfaces important during materials processing? If

so, what systems are most important? How are they presently measured?

Adhesion and interface properties are vital components in determining the

performance of a material. It is essential that sensors be developed for

their measurement during materials processing. Reinforcement-matrix

interface and adhesive bond strength are two very important systems where

sensors are needed. Others include solidification interface and grain

boundaries (for the control of reversible temper embrittlement in steels

for example). Very few techniques exist today for these measurements and none are in the form of process control sensors.

3. What physical phenomena might be available to form the basis of sensor

measurement methodologies?

For in situ sensors, any radiation that penetrates a material or is

naturally emitted (e.g., acoustic emission) may be the basis of a measurement technique. For example, ultrasound can be used to observe quantities

such as modulus, density, and temperature (at low frequencies). At higher

frequencies scattering from grains and elastic inhomogenieties promises

nondestructive microstructure characterization. Similar applications can be found with electromagnetic radiation. These include x-rays, dielectric

measurements, NMR, eddy currents, etc. A premium is to be attached to

techniques that provide spatially resolved information via tomography,

synthetic aperture, etc.

What is the present status of sensor R&D in (a) universities, (b)

industry, and (c) government?

University research is scattered and disjointed. Industry has several

problem-specific programs. Government is cooperating in several industry

programs, notably those associated with steel industry sensor needs.

53
5. What actions are to be recommended?

More interaction between universities, government labs, and industry are to

be encouraged. Generic sensor needs should be identified and addressed

through cooperative programs. A single company may find a sensor development uneconomic, but a joint research effort with several companies sharing

costs would spread the risk and promote the adoption of automated materials

processing throughout the industries’ infrastructure. This is a development that will be pivotal in the increasingly intensive competition of the

international marketplace.

6. What do we understand by adhesion and interfaces?

Adhesion - A bulk quantity related to the work required to separate an interface. . . . can only be directly measured by a destructive

test .

Interfaces - Regions separating materials with different physical and

chemical properties.

Examples: Liquid - solid interface

Ceramic - polymer interface

Ceramic - metal interface

7. Are adhesion and interface properties important during (and after)

materials processing?

Yes! But we do not have models that relate specific interface properties

to bulk behavior (both statically and during extended periods of use).

8. What systems are important?

Composites - Metal matrix composites promise an aerospace revolution;

solidification; adhesive bonds.

9. In priority order, what are the sensor needs?

We really do not know the answer yet! However, things of obvious importance

are: (a) adhesion - physical mapping of surface condition, contamination,

curing (molecular properties), adhesive thickness, porosity, and disbonds

and (b) interfaces - topology, temperature distribution, modulus (bulk and

local), and residual stress. Numerous indirect measurements will be re- quired with a premium on localized response methodologies, e.g., tomography,

synthetic aperture, embedded sensors.

10. What physical phenomena might form basis of sensor measurement

methodologies?

Fluorescent dyes, dielectric properties, and shear modulus to follow epoxy

cure for adhesion and composites; acoustic emission to characterize proof

testing for adhesion; interface elastic waves to characterize interfaces;

three-dimensional mapping of internal friction to characterize Interfaces;

embedded fiber optics for optically integrating interfaces; ultrasonic

scattering to probe interfaces; and NMR, x-ray (3"D) to characterize

internal structure.

54
11. What is present status of R&D in (a) universities, (b) industry, and

(c) government?

Large, profitable industries are addressing some of their own sensor needs —application driven. Need to involve university —student training issue.

Problem - few generic sensors identified; needs are fragmented.

Solution - cooperative research; AISI a model for this.

12. What actions are recommended?

Urgent need for sensors as tools to measure key variables in research

studies of processing —structure —property relations. Workshops need to be

convened for in-depth assessments of multidisciplinary issues associated

with adhesion and interfaces. Scientists and engineers must collaborate

more strongly.

Conclusion

Models do not exist for the relationships between interface properties

(including adhesion) and the bulk properties/performance characteristics of

components. Thus, it is not clear what must be measured in some systems

(particulate, polymer matrix composites).

55
i

I
APPENDIX B

SUMMARY OF CONSENSUS VIEWS

SUMMARY OF CONSENSUS VIEWS: INDUSTRY

Marvin S. Pittler

IBM - T. J. Watson Research Center

The papers and discussions in this Forum demonstrate a diversity of sensing

techniques that can be significant in improving productivity and product

quality across a range of industries. Sensors are an integral part of

process learning, and progressive yield and quality improvement that is

essential to the vitality of our competitive industries. The key role of

sensors and measurement is to provide rapid feedback to the process on the

important parameters influencing yield and quality. For example, in production of memory devices a primary factor in remaining competitive is

yield improvement, which is driven by the rapid sensing and eliminating of

yield detractors.

Overall, I see an increasing need for industry to apply measurement science

to the continuing improvement of processing in specific areas of manufacturing. Competitive pressures will not allow otherwise.

In parallel, I recognize the need for advances in measurement science that

provide the underpinnings for new sensors and measurement techniques.

University research in the area can be coupled to the more significant

opportunities by means of increased awareness of problems facing industry

segments. These opportunities go beyond flaw detection, NDE, and sensor

transducers to include contamination detection, surface measurement, electrical characterization metrology, and functional properties of materials.

My Specific Observations on This Forum

1 . Sensor and measurement requirements should be established by industry,

e.g., steel, electronics, chemicals, etc. The quality and defect detection

requirements for each are different, and the skills and specific technologies involved are often unique. In addition, the role of measurements in

process and quality improvement are different in the various industries.

2. More emphasis is needed on the use of specific measurements to improve

the process and on the appropriate trade-offs for sensor requirements. The

aim is to simplify the process and improve design margins for manufacturability such that many sensors and measurements become less critical. Tool

design and materials selection are a part of the sensor technology.

3. Sensors are used in several fundamentally different ways, each with

characteristic requirements

:

a) Process development and modeling.

b) Prevention and learning (predictability)

.

c) Process control and learning.

d) Detect and prevent the escape of defects.

59
4. The measurement system should be established and incorporated as part

of product development as well as manufacturing.

5. To be effective, the measurement system will include real-time data

handling, data reduction and analysis for daily decision making.

Topics and Directions For Future Forums

1 . Technology transfer and the role of manufactur ing /development

.

2. The role of government, universities, and industry in advancing the

sciences and technologies that will improve the competitive posture of U.S.

industry.

60
I

SUMMARY OF CONSENSUS VIEWS: UNIVERSITY

Gordon S. Kino

Stanford University

We have heard from Marvin Pittler the industrial point of view on the

problems of introducing manufacturing science to industry. We have similar

problems in the university environment. We have been trying to do something about manufacturing technology at Stanford and have been urged by

industry to do more. We believe manufacturing science is important, and we would like to contribute more in this field.

After looking at the subject, we do not feel that it is an academic

discipline as such. Rather, it would seem more suitable, in the academic

environment, to break the subject of manufacturing science into critical

components such as sensors, artificial intelligence, and techniques for

making semiconductors. This is the direction we are taking at Stanford.

We need, in this country, a critical mass to do a really good job in many

of the fields that would contribute to manufacturing science, for example, sensors. This requires cooperation between different industrial firms at

the basic science level. Unlike Japan, we have not been doing very much

about approaching the problem in this way. There are countless examples,

sensors being a good one, where the United States is probably spending far

more than Japan on research. There is, however, needless duplication and

lack of direction of the overall effort. Therefore, we are not getting as much from our total investment as the Japanese do when they decide to

concentrate on a particular problem. We must learn how to set up

mechanisms to cooperate with each other better.

There are already some examples of cooperation between between universities

and industry; the NSF engineering centers are a recent initiative in this

direction. Stanford has its own version of this kind of cooperation, the

Center for Integrated Systems. I will describe some aspects of this Center

here because it is a good example, and it is the one with which I am most

familiar.

The basic idea was to set up a sophisticated sub-micron integrated circuits

laboratory with mixed industrial and government financing. As part of this

agreement with industry, industrial people come to Stanford for a year or more to work with students, faculty, and each other. The program is at an early stage, but even after a relatively short experience, we find that not

only do industrial people interact well with students and faculty, but also

their strong interactions with each other have been extremely stimulating

for them. The presence of industrial people on campus has been very stimulating for us; some teach us how to organize our research better, others

bring know-how, yet others generate new ideas for research. We feel that

they learn a different point view at Stanford, particularly with regard to

looking at problems more fundamentally. One of the things that we hope we will learn from industrial interaction is how to make small numbers of

integrated circuits efficiently. The payoff would be large.

61
One of the fears expressed by industry about universi ty/industrial cooperation is the possibility of having new developments become more easily

available to our competitors. We believe that close cooperation between

Industries and universities will make the transfer of technology much

faster than by dissemination of information in technical papers. In a technical paper, the best results are published, but many of the difficulties are not apparent. It takes much longer to transfer information by the

typical publication route, because of the time required for publication and

because of the limited amount of information in the paper, than it does

when people work together. Therefore, we do not believe that this is a major problem as far as basic research ideas are concerned. It is one way

industry can learn to turn research ideas into a product much more quickly

than they do at present. The Japanese are much faster than we. Their time

from research to production appears to be half that of large-size American

industrial firms.

Overall, university /industrial cooperation will help this process. The

stimulation and contact with industry is very good for our students, and it

is good for industry because it makes students interested in their problems.

Along with cooperation in research on sensors and the broader field of

manufacturing technology, more publicity is needed. We hope to get bright

students for these important problems. We, therefore, need to find ways to

excite their interest in the field, and we need long-term financing. Then

we can set up the educational programs on sensors and plan for the long

term. We should avoid, if we can, turning the spigot on and off when interest in a subject waxes and wanes. We need to develop methodologies and

long-term basic research which leads to something useful and gives time to

transfer the technology to industry.

I would now like to discuss the subject of sensors in more detail. In an ideal world, sensors would be used during the manufacturing process to give

direct feedback so that the process could be controlled directly in real

time. We are not yet ready to do that with most manufacturing processes,

for the processes are usually not well enough understood to control them,

and we do not have adequate sensors or real-time processing available. If we are going to aim at this kind of manufacturing, we will need to redesign

some of the processes with feedback in mind, as well as the fact that

sensors will be part of it.

We need to take a more conservative approach initially, and not try to run before we can walk. Thus, we need to develop the sensors and apply them to

the problems we can solve. For example, we need sensors for metrology in

machining processes and for semiconductors. For machining processes, it

should be possible, fairly soon, to use the sensors in a feedback system to

control the machining processes. It is not easy, however, to try to incorporate sensors at the early stages of the manufacturing process where the

temperatures are high and conditions often highly corrosive. Rather, as we develop methodologies on the simpler problems, we should be able to learn

from our first results and use them to predict what will happen at the next

stage of the process or be able to determine what went wrong at the earlier

62
stages. Thus, in time, as we gain more experience, we will learn how to

make sensors for the more difficult stages of the process, which are

themselves not yet fully understood.

As far as sensor development is concerned, there are some common problems

where a broad thrust may help. Metrology is one of them, as are temperature measurements, but there are other problems which are not universal.

For example, the electronics industry needs to measure electronic properties. Other industries’ problems are quite different. Where there is a common theme, such as in metrology, we may well be able to develop generic

systems which can be made smaller or bigger, as needed. In other cases, we will have to develop appropriate sensors for much more specialized systems.

In conclusion, the development of sensors is fundamental to manufacturing

science. We need better quality control; a fundamental approach is to put

feedback into the manufacturing process. There is much to be done, and the

subject is very important. We must, therefore, put a major development

effort into the field.

63

SUMMARY OF CONSENSUS VIEWS: GOVERNMENT

H. Thomas Yolken

National Bureau of Standards

It is clear from the two days of discussions at this Forum that there is a substantial opportunity in the area of automated materials processing. We

have an opportunity to make gains in our industrial competitiveness in

areas involving the manufacture of advanced materials by taking advantage

of our knowledge base and national lead in materials science and engineering.

Advanced materials utilize complex microstructures to yield the desired

advanced properties and these complex microstructures are proving difficult

to process. This is so, because process models —the relationships between

process variables and resulting microstructure —are not well understood,

and adequate process control schemes are often lacking. Products made from

advanced materials, therefore, can lack reproducibility and this, in turn,

requires that products be overdesigned. Lack of reproducibility, thereby,

denies us access to the full potential of advanced materials. In addition,

current production of advanced materials is often labor intensive and requires costly post -processing inspection. Reject rates can be substantial

with the rejects typically not identified until late in the production

process, causing considerable loss.

In order to compete and take advantage of our knowledge-base lead, the U.S.

needs to undertake research to develop the scientific understanding for

improving process models and to develop automation techniques for advanced

materials processing. These automation techniques will be based on advanced

on-line process parameter and nondestructive evaluation sensors and expert

systems.

I am directing my principal remarks today to sensors and leaving the topic

of process models and expert systems for the next workshop. The sensor

problems and opportunities that we have reviewed at this workshop are somewhat difficult to categorize. There are several classes of sensor applications that appear to have some generic relationship with each other. A generic class of sensors to characterize and control the production of small

powders (metals, ceramics, and polymers) is one example. Another example of

generic sensor applications involves determining internal temperature pro

files in solids and liquids and determining liquid/solid interface positions

in two-phase systems. This is a tractable task for homogeneous mate rials

with simple geometry and isotropic properties. However, as with many nondestructive evaluation type sensor problems, the task grows more difficult

with complex geometries and inhomogeneous or anisotropic materials.

There is also a wide variety of sensor problems that are applications

driven and narrow in scope. These need to be worked on, one at a time,

with direct coupling to the specific problem.

65
For many of the problems that were discussed, there is a basis for a solution that is apparent in some existing sensor techniques. Adapting the

measurement technique to the problem offers a reasonable chance for success.

But there are some important problems where the basis for a relevant sensor

is not yet understood. An outstanding example is the problem of bond

strength or adhesion as exemplified in joining and composites.

In order to take advantage of the opportunities that are apparent in sensors

for automated materials processing, our R&D efforts must be focused and

reach a critical size. I believe that several of the Federal agencies,

such as the Defense Advanced Research Projects Agency, the National Science

Foundation, the National Bureau of Standards, and the Department of Energy,

could take the initiative and select a few model programs to jointly support. These programs would benefit from university, industry, and Federal

laboratory involvement. Industry could likewise take the initiative and

pursue cooperative research on sensors. In order to promote the formation of

cooperative R&D efforts, an industrial organization such as the Industrial

Research Institute could serve a valuable and impartial role in facilitating the formation of cooperative R&D efforts for sensors. Providing help

in the formation of cooperative R&D efforts on sensors could also provide a model for other cooperative R&D efforts.

66
APPENDIX C

SUMMARY OF CONCLUSIONS RAISED AT LAST SESSION
II
SUMMARY OF CONCLUSIONS RAISED AT THE LAST SESSION

by

Charles F. Larson, Executive Director

Industrial Research Institute

CONCLUSIONS

• A credibility gap is apparent between scientists and engineers in the

field of sensors.

• A need exists for the transfer of sensor technology from one industry

to another.

• Industry interaction and cooperation in the field of sensors is

required.

• Equipment manufacturers lack the critical mass needed in sensor

technology.

• Support of subcontractors is unstable.

• Short-term focus.

• Focal point needed for national action.

• Strong industry /university collaboration needed.

• Sensors urgently needed as tools for measuring key factors in

manufacturing.

• Application of new technology and concept lacking in the U.S.

• A valuable aspect of the conference was learning of the availability

of new sensors, thus avoiding the necessity of developing custom

sensors for one's own use.

SUMMARIES

Industry Perspective

• It is necessary to divide measurement requirements according to

industry because metrology is vastly different in different

industries.

• More emphasis is needed on the design of a process to accommodate

appropriate sensors.

• Measurement systems must be incorporated into original design for

manufacturing.

• Manufacturing should be raised to a level of higher importance in a company's strategic plan.

• Effective collaboration needed among industry, universities, and

government.

Academic Perspective

• Agree with necessity to divide sensor requirements by industry.

• Need to make better use of resources through cooperation.

• Interaction throiigh university cooperative programs is fruitful.

• Need stimulation of contact with industry.

• Need more publicity on problems in sensor technology to attract

bright students to the field.

69
Government Perspective

• Cooperative research in this field needs to be examined carefully.

• A champion is needed to provide thrust in creating cooperative

mechanisms.

• Need to stimulate application of new technology to commercial

products by rewarding persons to do it.

• Discussion groups during workshops needed more time for

deliberation.

70
APPENDIX D

WORKSHOP PROGRAM
I iIIIIIIII
CONFERENCE PROGRAM

Sunday, December 15

7:00 p.m. Early registration - mixer with complimentary

hors d 'oeuvres and cash bar

Sheraton

Monday, December 16

8:00 a.m. Registration

University of California at Santa Barbara

Campus 110^1

Co ffee /juice /dan ish

I OVERVIEW

Session Chairman:

Robert H. Mehrabian

Dean, College of Engineering

University of California/Santa Barbara

8:30 Welcome/Introduction

Announcement Details

8:45 Conference Goals

H. Thomas Yolken

Chief, Office of Nondestructive Evaluation

National Bureau of Standards

9:00 Challenges and Opportunities for

Automated Materials Processing

Robert Mehrabian

Dean, College of Engineering

University of California/Santa Barbara

9:45 Break

II SENSOR NEEDS FOR PROCESSING TECHNOLOGIES

Session Chairman:

Peter Bridenbaugh

Vice President, Research & Development

Aluminum Company of America

10:05 Electronic Materials

Augustus F. Witt

Department of Materials Science & Engr.

Massachiisetts Institute of Technology

73
10:25 Optical Materials

George H. Slgel

Director, Center for Fiber Optic Materials Research

Rutgers University

10:^15 Metals

Robert A. Sprague

Manager, Engineering Materials Tech. Labs.

General Electric

Martin Blackburn

Pratt & Whitney, Engineering

11:05 Ceramics

Roy Rice

Director of Materials Research

W. R. Grace and Company

11:25 Polymers

Frank E. Karasz

Professor, Department of Polymer Science

and Engineering

University of Massachusetts

11:^5 Basic Materials

James R. Cook

Principal Research Engineer

ARMCO Research

12:05 Composites

Bruce Kay

Manager of Composites Design & Develop.

Sikorsky Aircraft

12:25 Lunch

III SIMULTANEOUS WORKSHOPS ON SENSOR NEEDS FOR PROCESSING

TECHNOLOGIES

1:30 Electronic Materials

Discussion Leader: L. Eric Cross

Director, Materials Research Laboratory

Pennsylvania State University

Optical Materials

Discussion Leader: Jack McChesney

Bell Telephone Laboratories

Metals

Discussion Leader: Phillip A. Parrish

Program Mgr., Materials Sciences Div.

Defense Advanced Research Projects Agency

Ceramics

Discussion Leader: Fred Lange

Rockwell International Research Center

7 ^
Polymers

Discussion Leader: Witold Brostow

Professor, Dept, of Materials Engineering

Drexel University

Basic Materials

Discussion Leader: William Dennis

Vice President, Manufacturing & Technology

American Iron & Steel Institute

Composites

Discussion Leader: Richard S. Williams

United Technologies Research Center

3:30 Break

IV WORKSHOP REPORTS ON SENSOR NEEDS

Session Chairman:

Benjamin Wilcox

Asst. Director, Materials Sciences Division

Defense Advanced Research Projects Agency

3 : 50 Current and future sensor needs

Sensor priorities

Commonalities between processes

Does industry need cooperative

mechanisms to meet these needs?

Recommended actions

5:00 Adjourn

6:00 Cash bar and hors d ’oeuvres

6:30 Dinner (Faculty Club)

Tuesday, December 16

V SENSOR METHODOLOGIES FOR PROCESS CONTROL

Session Chairman:

Peter Cannon

Vice President, Research & Development

Rockwell International Science Center

8:30 Process Parameters, Temperature,

Pressure, Mass Flow, Gas Phase

Composition, etc.

Peter F. McCrea

Vice President, Research, Design,

Instrumentation, D&E

Foxboro Company

75
8:50 Dimensional Metrology

H. Kumar Wickramasinghe

IBM - T.J. Watson Research Center

9:10 NDE for Materials Characterization,

Ultrasonic and Eddy Current Techniques

R. Bruce Thompson

Ames Laboratory /Iowa State University

9:30 NDE for Materials Characterization,

Acoustic EiJiission, Thermal, Optical, and

Other Techniques

Robert E. Green, Jr.

Director, Center for Nondestructive Evaluation

Johns Hopkins University

9:50 NDE for Materials Characterization,

Real-time X-ray Radiography

Robert A. Buchanan

Manager, NDT Technology Laboratory

Lockheed Missiles and Space Co.

10:10 Break

10:30 Surface Properties

Homer B. James

Program Manager

Westinghouse R&D Center

10:50 Adhesion and Interfaces

Edmund G. Henneke, II

Dept, of Engineering Science & Mechanics

Virginia Polytechnic Inst. & State Univ.

VI SIMULTANEOUS WORKSHOPS ON SENSOR METHODOLOGIES

11:10 Process Parameters

Discussion Leader: Robert H. Bullis

Program Director, Sensor Technology

United Technologies Research Center

Dimensional Metrology

Discussion Leader: E. Clayton Teague

Leader, Micro & Optical Metrology Group

National Bureau of Standards

NDE for Materials Characterization

Discussion Leader: Bernhard R. Tittmann

Manager, Materials Characterization

Rockwell International Science Center

Surface Properties

Discussion Leader: L. Diaane Dunlap

Manager, Equipment Development Division

Aluminum Company of America

76
Adhesion and Interfaces

Discussion Leader: Haydn N. G. Wadley

Group Leader, Nondestructive Characterization

National Bureau of Standards

12:10 Lunch

1 : 15 Session VI Continues

2:15 Break

VII WORKSHOP REPORTS ON SENSOR METHODOLOGIES

Session Chairman:

Donald 0. Thompson

Principal Scientist

Ames Lab. /Iowa State University

2:35 Status of R&D on sensors

Status of university education in sensor field

Does industry need cooperative mechanisms?

Recommended actions

VIII SUMMARY OF CONSENSUS VIEWS

Session Chairman;

Jerome H. Schlensker

Vice Pres., Mfg., Planning & Support

Cummins Engine Co. , Inc.

3:35 Panel Discussion by Representatives from;

Industry

Marvin S. Pittler

Vice President, Manufacturing Research

IBM - T.J. Watson Research Center

University

Gordon S. Kino

Professor of Electrical Engineering

Stanford University

Government

H. Thomas Yolken

Chief, Office of Nondestructive Eval.

National Bureau of Standards

4:20 Adjourn

77
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APPENDIX E

WORKSHOP ATTENDEES

List of Workshop Attendees

A National Forum on the Future of Automated

Materials Processing in U.S. Industry

...The Role of Sensors...

December 16-17, 1986

University of California at Santa Barbara

Ligh Abts, Rexnord

Laszlo Adler, Ohio State University

Ralph P. I. Adler, Army Materials Technology Laboratory

Willialm F. Adler, General Research Corporation

Frederick X. Albrecht, Eastman Kodak Company

George A. Alers, Magnasonics

Marion D. Barker, Lockheed Missiles & Space Co.

George Birnbaum, National Bureau of Standards

Martin J. Blackburn, Pratt & Whitney

Kenneth G. Blaisdell, Johns Hopkins University

Shelly Bodnick, Exxon Research & Engineering Co.

Richard C. Born, Rexnord

Peter R. Bridenbaugh, Aluminum Company of America

Witold Brostow, Drexel University

Robert A. Buchanan, Lockheed Missiles & Space Co.

Robert H. Bullis, United Technologies Research Center

David L. Burk, Allegheny Ludlum Steel Corporation

Robert D. Burnham, Xerox

Heinz H. Busta, Gould Cardiovascular Products Division

Robert J. Calcaterra, Adolph Coors Company

Peter Cannon, Rockwell International Science Center

Kenneth Chen, Whirlpool Corporation

James R. Cook, Armco Inc.

Eric Cross, Pennsylvania State University

Frank A. Daniher, Calgon Corporation

William E. Dennis, American Iron & Steel Institute

Ramon P. De Paula, Jet Propulsion Laboratory

James E. Doherty, Magnaflux

L. Duane Dunlap, Aluminum Company of America

Donald G. Eitzen, National Bureau of Standards

Robert C. Frimodig, Pratt & Whitney

Vernon D. Gebben, Kerr-McGee Corporation

Robert E. Green, Johns Hopkins University

Thomas W. Gurley, Goodyear Tire & Rubber Company

William A. Harris, Air Force - Forecast II

Michael J. Haugh, Kaiser Aluminum & Chemical

Edmond G. Henneke, II, Virginia Polytechnic Inst. & State University

Donald F. Hoeg, Borg-Warner Research Center

David S. Hoover, Air Products & Chemicals

81
Theodore Hopp, National Bureau of Standards

Vincent V. Horvath, Bethlehem Steel Corporation

R. Hyman, University of California at Santa Barbara

Homer B. James, Westinghouse

George C. Johnson, University of California

Frank E. Karasz, University of Massachusetts

Bruce Kay, Sikorsky Aircraft

Bruce Kerr, Sherwin Williams Company

B. T. Khuri -Yakub, Stanford University

Yong W. Kim, Lehigh University

Gordon S. Kino, Stanford University

Donald E. Koontz, AT&T Bell Laboratories

Norman R. Kuchar, General Electric Company

George Kychakoff, Stanford University

Fred F. Lange, Rockwell International Science Center

Charles F. Larson, Industrial Research Institute

Carlos Levi, University of California at Santa Barbara

Saul R. Locke, Martin Marietta Aerospace

George A. Matzkanin, Southwest Research Institute

Robert Mehrabian, University of California at Santa Barbara

James W. McCauley, Army Materials Technology Laboratory

Robert W. McClung, Oak Ridge National Laboratory

Peter F. McCrea, Foxboro Company

William Meuli, Xerox

Keith W. Michael, Dow Corning Corpotation

Ron Miller, Alcoa Laboratories

John C. Murphy, Johns Hopkins University

Gary L. Neiheisel, Armco Inc.

Phillip Parrish, Defense Advanced Research Projects Agency

William H. Payne, E.I. Du Pont de Nemours & Co.

Marvin S. Pittler, IBM - T. J. Watson Research Center

Adrian Pollack, Physical Acoustics Corporation

C. F. Quate, Stanford University

Yapa Rajapakse, Office of Naval Research

Steven Reichman, Wyman-Gordon

Darrell H. Reneker, National Bureau of Standards /OSTP

Roy W. Rice, W.R. Grace & Co.

David Richman, RCA Corporation

Hal Rosen, IBM

Allan Rosencwaig, Therma-Wave, Inc.

Clayton 0. Ruud, Pennsylvania State University

Kamel Salama, University of Houston

Jerome H. Schlensker, Cummins Engine Company

Eric Schlienger, Retech Corporation

Ron Schmid, 3“M Corporation

Lyle H. Schwartz, National Bureau of Standards

George C. Schweiker, PQ Corporation

George H. Sigel, Rutgers University

D. H. Smithgall, AT&T Bell Laboratories

Robert Snyder, Manville Service Corporation

David J. Spottiswood, Colorado School of Mines

Robert A. Sprague, General Electric Company

Robert C. Sundahl, Signal Research Center

82
Whalun Szeto, Retech Corportation

E. Clayton Teague, National Bureau of Standards

David Tiede, Cummins Engine Company

Donald 0. Thompson, Iowa State University/Ames Laboratory

R. Bruce Thompson, Iowa State University /Ames Laboratory

Bernhard Tittmann, Rockwell International Science Center

John C. Ufford, E.I. du Pont de Nemours & Co.

Haydn N. G. Wad ley. National Bureau of Standards

Michael J. Wargo, Massachusetts Institute of Technology

Steven G. Wax, Defense Advanced Research Projects Agency

H. Kumar Wickramasinghe, IBM - T.J. Watson Research Center

Richard S. Williams, United Technologies Research Center

H. Thomas Yolken, National Bureau of Standards

83

NBS-114A (REV. 2 .80 ) U.S. DEPT. OF COMM.

BIBLIOGRAPHIC DATA

SHEET (See instructions)

1 . PUBLICATION OR

REPORT NO.

NBSIR 86-3341

2. Performing Organ. Report No, 3. Publication Date

May 1986

4. TITLE AND SUBTITLE

A National Forum on the Future of Automated Materials Processing in U.S. Industry

The Role of Sensors

5. 3^i«5r*l!0!8!i54 Editors

H. Thomas Yolken and Robert Mehrabian

6. PERFORMING ORGANIZATION (If joint or other than NBS. see instructions)

University of California at

Santa Barbara national bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 20234 Santa Barbara, CA 93106

7. Contract/Grant No.

8. Type of Report & Period Covered

9. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street, City, State, ZIP)

Industrial Research Inst., Inc.

100 Park Avenue

New York, NY 10017

White House Office of Science & Technology Policy

AND Committee on Materials, Working Group on Automating

of Materials Processing

New Executive Ofc. Bldg., Room 5005

10. SUPPLEMENTARY NOTES Washington, U.C.—ZU5UF

Q J Document describes a computer program; SF-185, FIPS Software Summary, is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bi bliography or literature survey, mention it here)

This is the proceedings of the workshop "A National Forum on the Future of Automated

Materials Processing in U.S. Industry - The Role of Sensors." This is the first of two

workshops to be sponsored by the Industrial Research Institute and the White House

Office of Science and Technology Policy, Committee on Materials Working Group on Automation of Materials Processing. The second workshop will address the other two key components required for automated materials processing, process models and artificial

intelligence coupled with computer integration of the system. The objective of these

workshops is to identify and assess Important issues affecting the competitive position

of U.S. industry related to its ability to automate production processes for basic and

advanced materials and to develop approaches for improved capability through cooperative

R&D and associated efforts.

12. KEY WORDS (S/x to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolon s) automated materials processing; ceramics; composites; metals; nondestructive evaluation;

polymers; sensors; workshop

13. AVAILABILITY

(X ) Uni imited

[ I For Official Distribution. Do Not Release to NTIS

[ I Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402.

I X I Order F rom National T echnical Information Service (NTIS), Springfield, VA. 22161

14. NO, OF

PRINTED PAGES

76

15. Price

$ 11.95

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