Laser Surface Treatment of Metals

NATO ASI Series Advanced SCience Institutes Series

A Series presenting the results of activities sponsored by the NATO Science Committee, which aims at the dissemination of advanced scientific and technological knowledge, with a view to strengthening links between scientific communities.

The Series is published by an international board of publishers in conjunction with the NATO Scientific Affairs Division

A Life Sciences Plenum Publishing Corporation B Physics London and New York

C Mathematical and D. Reidel Publishing Company Physical Sciences Dordrecht and Boston

0 Behavioural and Martinus Nijhoff Publishers Social Sciences DordrechtiBoston/Lancaster

E Applied Sciences

F Computer and Springer-Verlag Systems SCiences Berlin/Heidelberg/New York

G Ecological Sciences

c% Series E: Applied Sciences - No. 115

Laser Surface Treatment of Metals

edited by

Clifton W. Draper AT & T Engineering Research Center Princeton, NJ 08540 USA

and

Paolo Mazzoldi Padova University Department of Physics Pad ova 35131 Italy

1986 Martinus Nijhoff Publishers Dordrecht / Boston / Lancaster

Published in cooperation with NATO Scientific Affairs Division

Proceedings of the NATO Advanced Study Institute on Laser Surface Treatment of Metals, San Miniato, Italy, September 2-13, 1985

Library of Congress Cataloging in Publication Data

NATO Advanced Study Institute on Laser Surface Treatment of Metals (1985 : San Miniato, Italy) Laser surface treatment of metals.

(NATO advanced science institutes series. Series E, Applied sciences ; 115)

Proceedings of the NATO Advanced Study Institute on Laser Surface Treatment of Metals, San Miniato, Italy, September 2-13, 1985"--P. iv.

Includes index. 1. Metals--Finishing--Equipment and supplies-­

Congresses. 2. Metallurgy--Laser use in--Congresses. Draper, Clifton W. II. Mazzoldi, Paolo. III. Title. IV. Series. TS653.5.N37 1985 671'.7 86-21766

ISBN-13: 978-94-010-8489-5 e-ISBN-13: 97 8-94-009-4468-8 001:10.1007/978-94-009-4468-8

Distributors for the United States and Canada: Kluwer Academic Publishers, 101 Philip Drive, Assinippi Park, Norwell, MA 02061, USA

Distributors for the UK and Ireland: Kluwer Academic Publishers, MTP Press Ltd, Falcon House, Queen Square, Lancaster LA1 1RN, UK

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All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publishers, Martinus Nijhoff Publishers, P.O. Box 163, 3300 AD Dordrecht, The Netherlands

Copyright © 1986 by Martinus Nijhoff Publishers, Dordrecht Softcover reprint of the hardcover 1st edition 1986

v

I N T ROD U C T ION

This book contains the papers presented at a NATO Advanced Study Institute held at S. Miniato, Italy, from September 2 to 13, 1985, on the latest developments in the science and technology of modifications, in particular, of metallurgical surfaces due to laser treatment.

The objectives of the meeting were twofo1 d. First, to infonn par­ticipants of actual and developing technological applications of laser treatment in which fundamental science makes a strong contribution; second, to bring together scientists from widely different cultural backgrounds in material science and technology to promote mutual under­standing and collaboration.

Laser surface processing comprises different operational regimes, depending on the interaction time and laser beam energy. By changing the characteri sti cs of the 1 aser-materi a1 interacti on spectrum, a variety of modifications are possible, as transfonnation hardening, deep penetration wel ding, laser glazing, drill ing, metastable alloys fonna­tion, and shock hardening.

The mechani sm by whi ch the laser 1 i ght energy is absorbed by the material surface and the heat transfer models for evaluation of the melt depth and temperature obtained with different laser inputs are examined, in tenns of technology applications, by many lecturers. The effective­ness of enhanced absorpti on techni ques in the laser energy transfer to the metal surfaces has been analyzed in detail. The modification metal­lurgy and the variety of modifications which are possible have been in­vestigated in the main part of the meeting, focusing on the performance of the modified surfaces.

In addition, some seminars have been devoted to laser anneal ing of semiconductors, the interaction of laser beams with living tissues, pro­duction of superconducting alloys by laser annealing and Guenching, and laser preparation of metal surfaces for telecommunication needs.

An interesting comparison between different direct energy sources, as laser, electron or ion beams, has been presented by some lecturers.

The last session was devoted to development in laser material pro­cessing for the automotive industry with the contributions of experts from FIAT, General 1·lOtors and Roll s-Royce Industri es.

The interdisciplinary nature of the meeting appears clearly in the wide range of interest in the material delivered by the lecturers.

Finally, probable directions for future research are discussed. We thank all the chairmen, lecturers and participants who cooperated

in the discussions and exchanges in different discip1 ines and between applied technologies and basic research.

VI

We thank a1 so all those organizations who generously supported the meeting:

NATO, Scientific Affairs Division, provided the major balance of the funds under the framework of the NATO double-jump program for generating closer collaboration between industry and basic research organizations of the member countries.

The industrial and national organizations below responded promptly, ensuring the remaining support:

Institute Co-Sponsors

American Society for Metals Centro Informazioni Studi Esperienze Cilas A1cate1 Coherent General Consiglio Naziona1e Delle Richerche Ente Naziona1e Energia A1ternativa European Research Office (USARDSG) Ferranti, p1c FlAT General Electric Company, p1c The Institute of Metals International Society for Optical Engineering The Laser Institute of America Laser Optronix, sr1 The Materials Research Society The National Science Foundation Ne\~port Corporati on Padova University Soitab Val fivre

lie are a1 so very grateful to AT&T for assi stance and support in the organization of the meeting and preparation of the book. In particular, Mary F. Edsall, whose skill at the word processor and editorial secre­tarial experience proved indispensable.

The support of these agencies, societies and companies made the attendance of 16 graduate students possi b1 e. These graduate students collectively wrote a meeting synopsis for their sponsors and we have decided to print it below as part of the book introduction.

EDITORS' INTRODUCTION - GRADUATE STUDENTS' REPORT

COMPILED BY DALE C. JACOBSON Stevens Institute of Technology and AT&T Bell Laboratories

VII

The NATO Material Science Panel has recognized for the past decade that laser treatment of surfaces is a field of enormous growth and that the technology developed by member countries should be shared. To this end NATO authorized an ADVANCED STUDY INSTITUTE. dedicated to LASER SURFACE TREATMENT OF METALS. under the direction of Dr. C. W. Draper of AT&T. USA. and Professor P. Mazzoldi of Padova University, Italy. The Institute took place in September. 1985, in San Miniato, Italy. The nine-day program included lectures. 90-minute talks, and contributed papers. 45 minutes in length. The Institute consisted of 18 lectures, 35 invited participants and 16 graduate students, for a total of 69 attendees.

Monda~, September 2 Fo lowing a brief welcome and introduction by Clif Draper and Paolo

Mazzoldi, the first session began with a talk by Prof. Walter Duley of York University in Canada. His presentation dealt with the quantity of energy deposited by a laser in the material being irradiated. Extensive studies have been performed to measure the reflection and transmission of laser irradiation which decrease the energy coupled to the material. The most striking result was the sensitivity of reflection to the clean­liness of the surface of the sample. If one is going to predict. the reflectivity of a surface, that surface must be atomically clean. Wave­length and temperature dependence were also discussed.

Todd Rockstroh. a graduate student from the University of Illinois. presented a paper dealing with the production of plasmas by laser irra­diation of metal surfaces. A two-dimensional model for the plasma tem­perature above the heat-affected zone was developed. Temperature mea­surements of the plasma were made using relative line intensity emission spectroscopy.

The afternoon session began with a presentation by Dr. Jean-Pierre Girardeau-Montaut. describing preliminary results of high-frequency. short-pulse laser irradiation of tungsten. A train 1 usee long of pulses 35 psec or less of UV or visible light was used to induce thermal and mechanical effects in the metal. It was shown that very rapi d and periodic variations in temperature at the surface induce large stresses in the material.

Dr. Fritz Keilmann reported on a new mechanism of laser-material interaction. Stimulated scattering of laser light into surface electro­magnetic waves which in turn are absorbed by the material. Surface rippling. a commonly observed phenomenon, can be explained by this model. It was shown the surface waves are strongly polarized.

The first session ended with a talk by Prof. Dona dalle Rose, where he showed the resu1 ts of computer modeling of ultra rapi d heat flow

VIII

resulting from pulsed laser irradiation of metal surfaces. Diffusion of implanted impurities in the mol ten phase, segregation of these impuri­ties upon recrystallization, and mixing of alternating layers as a result of laser irradiation of metals were discussed.

Tuesday, September 3 Dr. Frans Spaepen demonstrated mel t quenching rates of 1012 K/sec

for 30 ps pulsed laser radiation. The high rate promises the formation of new metastable/crystalline phases and metallic glasses. In particu­lar, various Ni-Nb systems (23-81% Ni) were melted, with glasses forming far below the To lines over the entire range of Ni.

Dr. Paul Peercy showed the resu1 ts of 1 aser mel ti ng of meta 11 i c (A1-Ni) systems with 10-100 ns pulses. The rapid solidification sup­pressed the formation of complex phases. Thus, a comparison of the laser-induced phases with ion implantation phases (currently under way) will permit the primar,y thermo~namic and kinetic processes to be evaluated.

It was shown by Steve Williamson, utilizing picosecond electron dif­fraction, that superheating can occur in 25 nm freestanding A1 films. He attributes the onset of melting to the formation of defects.

Carolyn MacDonald utilized transient reflectance to measure melt lifetimes and melt/solid interface velocities in pure metals. It was shown that using a frequency doubled Nd-YAG 20 ps laser, interface velocities range from 60-100 meters/sec. This range of velocities implies a collision-limited regime.

Prof. Paolo Mazzo1di showed the surface peak formation resulting from laser-irradiated La- and EU-i.mplanted Ni systems. In a low-pressure oxygen or water vapor atmosphere, the effect is attributed to oxidation and solute trapping at the surface. A liquid phase diffusion analysis accounting for the two mechanisms reproduced the experimental results.

Joachim Froh1ingsdorf discussed the formation of amorphous Ga by irradiating a cr,yogenically cooled crystalline Ga substrate. An inter­esting feature was the repeatable switching of the substrate behavior between phases as the sample was heated a few degrees Kelvin and recooled.

Dale Jacobson demonstrated the laser melting of graphite (HOPG) at 4300 K at low ambient pressure and temperature. The results of TEM, and Rutherford backscattering and channeling implied that the liquid phase had indeed occurred. A free-electron gas model was shown to accurately predict the melt depth.

Aubrey Helms appl ied the techniques of Low-Energy Diffraction-Spot Profile Analysis (LEED-SPA) and RBS to the investigation of the struc­tural reponse of single-crystal Mel and Bi samples to high-power laser pulses. The results indicate that the samples deform plastically in response to the high thermal stresses via the activation of dislocation sources lying on the major slip planes.

wednesd~, Se~tember 4 Dr.ohnoate, Dr. Paul Peercy and Prof. Ugo Campisano presented

three lectures on semiconductor-laser interactions. Intense interest in laser heating of semiconductors was generated a decade ago by the obser­vation that ion implantation damage could be removed by laser melting. Defect-free crystals result from liquid phase epitaxy after pulsed laser irradiation yielding reso1idification velocities up to 15 m/s with little segregaton of the implanted dopant. At higher velocities

IX

amorphous silicon is formed. Thermodynamic calculations give an estimate for the first-order melting temperature of amorphous Si 250 K below that of the crystalline material. This can be confirmed by calorimetry, transient conductance measurements. and observations of explosive crystall ization. Lasers have proved unwieldy for bulk indus­trial application in silicon. but the understanding of the silicon re­growth processes 1 ed to the development of rapi d thermal anneal i ng fur­naces and strip heaters. Models for describing solute trapping were presented by Dr. Michael Aziz and compared to data obtained from tran­sient conductance measurements. Any description of the process requires deviation from local equilibrium; the most successful models also assume collision-limited growth.

Thursd~. September 5 Pro~ Jyotirmoy Mazumder lectured on creating a three-dimensional

mathematical model for melting. mixing and resolidification as a result of cw laser irradiation. Mass and momentum transfer were included as well as heat conduction.

Dr. Gabriel Laufer presented a talk about the application of lasers in medicine - specifically. their use as a surgical cutting and cauter­izing instrument. A thermodynamic model was developed to explain the damage to the surrounding tissue.

Dr. Michael Berry discussed the ablation of graphitic carbon and TaC as a result of higher power cw OF laser irradiation. He has measured the mass and energy distribution of the atoms that are removed from the surface as well as methods of protecting the surfaces agai nst 1 aser irradiation.

Dan Gnanamuthu presented a paper describing the problems one encoun­ters when trying to apply laser technology to real industrial applica­tions. such as beam shaping. polarization, energy coupling and heat transfer that affect solid phase transformations during surface modifi­cation. Mathematical models were presented that may be used to evaluate these parameters.

Paolo Gay talked about the work he has done with phosphate-based surface coating to increase the absorption of energy by the irradiated material. A two-dimensional model has been developed to explain the presented data.

Etienne Petit described how he had used AES and XPS to examine Al-Sb multilayered structures that had been prepared. laser irradiated and analyzed in UHV. Al-Sb alloy films are of interest in the field of optical data storage.

Ralf Koppmann described a technique in which Li and Al films were ablated by a Q-switched ruby laser. The energy and density distribu­tions of the ablated particles were measured as a function of time by laser-induced fluorescence and mass spectroscopy. From this information plasma temperatures were calculated. This technique has a possible application of measuring very high temperatures. for example. in nuclear reactors.

Fri d~. September 6 Te day began with a comprehensive account of the physico-chemical

effects of laser-gas interaction as related to Laser Chemical Vapor Deposition (LCVD). Prof. Jean Tardieu de Maleissye lectured on laser chemistr,y and. in particular. surface and gaseous phase chemistry impor­tant in LCVD processes. Dr. Tom Jervis then presented results using a

x

pulsed C02 laser to deposit metal films via LCVD. Depositions of Ni. Mo. and W have been produced and exhibit respectable conductivities. Interest in this cold deposition technique ranges from microelec­tronics to large-area coatings. The third talk by Dr. Jean-Pierre Celis described a technique that used a Nd:YAG laser to control the deposition rate in an electroplating process. Analysis of the thermal the electro­chemical effects as well as optimal laser parameters of this technique were presented.

Finally. Prof. Lindsay Greer described the results of two separate experiments. The first showed rapid reso1idification using picosecond laser pulses. The stuqy of nucleation can benefit greatly from experi­ments performed on this fast· time scale. Secondly. he presented the principles and applications of laser ionization mass analysis. citing the technique's importance as a versatile and most convenient first approach in microanalytic investigation.

Monday. September 9 The sixth day of lectures involved surface modifications to metallic

substrates for engineering applications. Dr. Hans Bergmann started the day with a comprenensive paper on

continuous-wave C02 laser melting of cast irons. He described two approaches to this process: deep penetration surface melting and finish grinding. or precision casting (grinding if necessary) and surface me1t­i ng. The hardnesses of the surface 1 ayers depended on the substrate material (ferritic. pearlitic. bainitric or austenitic) and graphite morphology (flakY or spheroid). Excellent wear properties in abrasive. adhesive and sliding/rolling tests were found. and these were borne out in actual component tests in a car engine. Push-pull and rotating bend­ing tests showed a degradation in fatigue properties. but this was not thought to be critical when compared with the surface hardening and wear properties produced.

The second paper presented by Enunanuel Kerrand described the trans­formation hardening of 12% chromium steels by continuous-wave C02 1 asers. The geometry and hardness of the treated zones wi th respect to different beam geometri es was descri bed and resul tant residual stresses discussed. Graphite and black paint were used to improve coupling effi­ciencies. with black paint proving the better. Surface melting a chromium steel and low alloy steels was also carried out. along with cladding of a cobalt-based alloy.

Prof. Emi 1 i 0 Ramous descri bed in the thi rd paper the behavi or of two absorbent coatings: DAG graphite and silica applied in the form of water glass. The efficiency of the coatings was assessed by measuring the temperature at the rear of the specimens. with graphite proving the more efficient. The interaction between carbon and the substrate in both solid phase and surface melting treatments was reported.

Prof. Bill Steen started the afternoon session with a description of laser surface cladding. He discussed pre-placed powder beds. blown pow­der and particle injection techniques and concluded the blown powder technique was the easiest to use. With close control of powder feed rate and beam power. an absolute minimum of substrate is melted. result­ing in minimum dilution of the clad layer. The optimum angle of inci­dence for blowing' powder was discussed and the additional benefit of enhanced energy coupling by the powder noted. The relationships between treatment parameters and resultant microstructures were discussed.

XI

Janet Folkes described the surface melting of titanium alloys and the resol idified microstructures, and went on to describe surface alloying with nickel pre-positioned by electroplating, platinum pre-positioned by ion-plating, and silver applied in a colloidal suspension. A problem with titanium and its alloys is its susceptibil ity to wear. A solution to this problem was suggested in the surface alloying with nitrogen to form a resol idified microstructure containing primary TiN. The struc­tural features of the melt zone were reported and mechanisms for their formation discussed.

A second paper by Prof. Ramous reviewed the application of C02 laser surface melting to cast iron, steels and stellite alloys. It des­cribed the fine microstructures achieved in these materials, which in­cluded the complete solution of carbides in an alloy steel. Laser clad­ding with stellite resulted in higher hardnesses than the same clad with either the T.I.G. or acetylene process because of the finer micro­structure.

The fi na 1 paper of the day, presented by Charl es Marsden, descri bed laser carborizing of a martensitic stainless steel used in steam turbine blades, with an aim to overcome erosion problems. The carbon was applied in the form of colloidal graphite. A range of carbon content through hypoeutectic to hypereutectic compositions was obtained by in­creasing the number of repeated tracks. Large quantities of retained austenite were found and remained present even when quenched to liquid nitrogen temperatures.

Tuesday, September 10 Dr. Ed McCafferty described his work improving the corrosion proper­

ties of materials using lasers. He concentrated on the laser processing of various stainless steels and Al alloys. He discussed the "normaliz­ing" of 304 stainless steel and its improvement to have properties simi­lar to that of 316 stainless steel.

Prof. Jyotirmoy Mazumder presented a talk centering around the use of laser surface alloying and powder feed techniques for the development of corrosion and wear-resistant coatings. Several examples were given which included the formation of Fe-Cr-Ni alloys which mimic the corro­sion properties of 304 stainless steel. Another example was the use of this technique to develop Fe-Cr-Mn-C alloys with good wear resistance.

Cl aude Chabrol reported investi gati ons of the resi dua 1 stresses in­duced in various steels after laser transformation. They studied the effect of a \'1ide variety of parameters such as initial state laser power, interaction time and beam shape. Their analysis indicated com­pressive stresses within the treated region and tensile stresses in the transition zone.

Dr. Bernd Stritzker has been working to determine if pulsed laser quenching can be used to form new metastable materials with enhanced superconductivity properties. His talk centered around work done with anisotropic compounds. The conclusion was that there is hope that the laser may be used to quench new metastable materials, which will have the high Tc desired for superconducting materials.

Dr. Clif Draper outlined a number of uses of lasers in the tele­communications industry. Emphasis was made on why the laser had advan­tages in each of the applications reviewed. The laser has been used for surface treatment and surface all oyi ng along with a vast array of other applications. The advantages and disadvantages of various types of lasers were discussed in relation to critical laser and materials parameters which are important in each application.

XII

Dr. Canoen Afonso discussed the possibility of using the laser to develop new materials for optical storage. Much of the discussion con­centrated on results of the Ge/Al system. She showed they could successfully produce amorphous Ge/Al films. They al so observed mixing in both alloyed and eutectic films, with metastable phases being pro­duced in the case of premixed systems.

Wednesday, September 11 The session started with a very informative talk on the development

in laser material processing for the automotive industry, given by Dr. Aldo La Rocca. The talk concentrated on how the heat conduction equation can be solved given different boundary conditions and the dif­fusivity term. He correlated the physical parameters that were pre­dicted with those that were measured. The model was then extended to more complex problems and used to understand practical problems in the auto indust~, such as the cladding of valves.

Malcolm Macintyre from Rolls Royce discussed the use of lasers within their company. He said the use of electron beam welding was extensive in the production of modern engines and laser welding also had potential applications in manY areas of the engine. Lasers were in production use for small hole drilling and laser cladding of turbine blades with cobalt-based alloys. Control of dilution to give optimum wear resis­tance and prevention of cracking in the heat-affected zone were impor­tant technical factors. In addition to substantial econ~mic benefits in the use of lasers for this application, he emphasized in his talk the extensive testing needed before the introduction of new manufacturing techniques in order to meet the requirements of the Civil Aviation Authority.

The last speaker of the day was Dr. David Roessler of General Motors. He described the use of lasers at General Motors for cutting, welding, hardening, and cladding of parts and material. Laser alignment of parts and tools was discussed as well as the chemical analyzers of auto exhaust.

Thursday, September 12 Dr. Elton Kaufmann emphasized that in contradiction to pulsed laser

irradiation, in the scanned laser cases the isotheno velocity increases as it approaches the surface, resulting in very different morphologies. His work described the behavior of Fe40Ni40P14B6 and a near eutectic composition of a Ta-Ir alloy. The above was used in order to explain the appearance of an amorphous overlayer above an initially polycrystalline regrown layer. The results were related to TTT curves.

Professor Barry Mordike suggested that gaseous laser surface alloying was dependent upon the equil ibrium constant "K. II He then went on to describe in considerable detail how gaseous nitriding, de-nitriding, carburizing and oxidizing of commercially pure titanium, IMI 318 and some iron-based alloys were related to K. Repeated cycles of treatment were also described. Methods of carbon and nitrogen detection were described as well as typical surface roughness. The effects of laser surface alloying on possivation currents, fatigue and tensile properties were also elucidated.

This NATO Study Institute certainly presented a broad scope of tech­niques and materials approached both from a science and engineering point of view. The interaction of scientists, engineers and graduate students was an excellent format for a cooperative learning experience.

XIII

This was especially true for the student attendees, who had an oppor­tunity to see both the theory and application of laser solid interactions.

xv

TABLE OF CONTENTS

INTRODUCTION C. W. Draper and P. Mazzoldi v

GRADUATE STUDENTS' REPORT compiled by Dale C. Jacobson • • • • • • • • • • • • • • • • • vii

CHAPTER 1. INTERACTION AT METAL SURFACES

CHAPTER INTRODUCTION W. W. Dul ey • • •

LASER MATERIAL INTERACTIONS OF RELEVANCE TO METAL SURFACE TREATMENT

W. W. Dul ey • . • • • • . . • • • . • • • • . •

STIMULATED ABSORPTION OF C02 LASER LIGHT ON r~ETALS Fri tz Kei 1 mann • • • • . • • • • • . • • • . •

CHARACTERIZATION OF LASER-INDUCED PLASMAS AND TEMPERATURE MEASUREMENT DURING LASER SURFACE TREATMENT

3

17

T. J. Rockstroh and J. Mazumder • • • • • • • • • • • 23

LASER/MATERIALS INTERACTIONS: CW OF LASER ABLATION OF CARBON Richard F. Menefee, Brendan D. Krenek, and ~lichael J. Berry 31

SPECTROSCOPIC STUDY OF ATOMIC BEAMS GENERATED BY LASER ABLATION OF MULTI-COMPONENT TARGETS

R. Koppmann, S. M. Refaei and A. Pospieszczyk • • • • • • •• 41

EDITED QUESTIONS - CHAPTER 1 Duley, Keilmann, Rockstroh, Berry, Koppmann •

CHAPTER 2. FUNDAMENTALS OF PHASE FORMATION IN LASER ANNEALING OF METALS

CHAPTER INTRODUCTION F. Spaepen and P. S. Peercy ••••••••••••

SOLIDIFICATION DYNAmCS AND MICROSTRUCTURE OF METALS IN PULSED LASER IRRADIATION

P. S. Peercy •••••..•••• . • • • • • • •

53

55

57

XVI

THERMODYNAMICS AND KINETICS OF METALLIC ALLOY FORMATION BY PICOSECOND PULSED LASER IRRADIATION

Frans Spaepen • • • • • • • • • • • • • • • • • • • • • 79

CRYSTALLIZATION AND NUCLEATION PHENOMENA IN CW SURFACE MELTED ALLOYS E. N. Kaufmann and R. J. Wallace •• • • • • • • • • • • • •• 93

THE KINETICS OF RAPID CRYSTALLIZATION IN PURE METALS C. A. MacDonald and F. Spaepen •••••••••••••••• 111

GENESIS OF MELTING S. Williamson and G. Mourou •• 125

AMORPHOUS GALLIUM PRODUCED BY PULSED EXCIMER LASER IRRADIATION J. Frohlingsdorf and B. Stritzker • • • • • • • • • • • • • 133

DEFECT STRUCTURES ON METAL SURFACES INDUCED BY PULSED LASER IRRADIATION: CHARACTERIZATION BY LEED-SPOT PROFILE ANALYSIS AND He+ ION CHANNELING

Aubrey L. Helms. Jr •• Chih-Chen Cho. Steven L. Bernasek. Clifton W. Draper. Dale C. Jacobson. John M. Poate. • •• 141

A1Sb FORMATION IN UHV BY LASER ANNEALING OF EVAPORATED Al AND Sb FILMS. CHARACTERIZATION BY AES AND XPS

E. Petit. P. Warnant. P. A. Thiry. R. Caudano • • • • • • • •• 157

LASER TREATMENT OF La-IMPLANTED Nf SINGLE CRYSTAL G. Battaglin. A. Carnera. G. Della Mea. V. Kulkarni. P. Mazzoldf. D. K. Sood. and A. P. Pogarny •••••

EDITED QUESTIONS - CHAPTER 2

. . . .,. 163

Peercy. Spaepen. Williamson. MacDonald. Mazzoldi. Frohlingsdorf. Jacobson. Helms. Petit. Kaufmann ••• • • • • • • • • • . •• 175

CHAPTER 3. MODELING OF HEAT AND MASS TRANSFER

CHAPTER INTRODUCTION L. G. Dona dalle Rose • • • • • • • • 181

MATHEMATICAL MODELING OF LASER SURFACE TREATMENTS Joyti Mazumder •••••••••••••• • •

APPLICATION OF MATHEMATICAL HEAT TRANSFER ANALYSIS TO HIGH-POWER C02 LASER MATERIAL PROCESSING: TREATMENT PARAMETER PREDICTION. ABSORPTION COEFFICIENT MEASUREMENTS

185

Pao 10 Gay • • • • • • • • • • • • • • • • • • • • • • • • • 201

HEAT AND MASS TRANSFER IN PULSED LASER HEATING L. F. Dona dalle Rose ••••••••••• 213

NUMERICAL RESULTS OF THERMAL ACTIONS INDUCED BY HIGH-FREQUENCY SHORT-PULSED LASER TRAINS ON METALS

XVII

Claire Girardeau-Montaut and Jean-Pierre Girardeau-Montaut • • 235

NUMERICAL DESCRIPTION OF THE INTERACTION OF LASER BEAMS WITH LIVING TISSUE

El i ahu Armon and Gabri e 1 Laufer • • • • • • . • • • • • • 249

SUMMARY AND DISCUSSION - CHAPTER 3 L. G. Dona dalle Rose • . • • • • . • • • • . • • • • • • 257

CHAPTER 4. PROPERTIES OF LASER-PROCESSED METALLIC SURFACES

CHAPTER INTRODUCTION B. Stritzker, E. McCafferty 261

ELECTROCHEMICAL BEHAVIOR OF LASER-PROCESSED METAL SURFACES E. McCafferty and P. G. Moore • • • • • • • . • . • • • 263

LASER SURFACE ALLOYING AND CLADDING FOR CORROSION AND WEAR J. Mazumder, J. Singh. • • . • • • • • • • • . • • • • 297

LASER PREPARATION OF METAL SURFACES FOR TELECOMMUNICATION NEEDS Clifton W. Draper. • • . • . . . • • • • • • • . • • • • • 309

LASER ANNEALING AND LASER QUENCHING: PRODUCTION OF SUPERCONDUCTING ALLOYS

Bernd Stritzker ••••.••••.•••••••••.•.•• 319

LASER PROCESSING OF Al-Ge MULTILAYER THIN FILMS C. N. Afonso and C. Ortiz ••••••.

EDITED QUESTIONS - CHAPTER 4 McCafferty, Mazumder, Draper, Stritzker, Afonso

CHAPTER 5. RECENT DEVELOPMENTS IN LASER SURFACE TECHNIQUES FOR ENGINEERING APPLICATIONS

CHAPTER INTRODUCTION

333

343

H. W. Bergmann, B. L. Mordike and W. M. Steen. • • . • • . •• 349

LASER SURFACE MELTING OF IRON-BASE ALLOYS H. W. Bergmann •••••••••••••••••••••••• 351

LASER SURFACE CLADDING W. M. Steen • • • • 369

XVIII

LASER GAS ALLOYING B. L. Mordike •

LASER HEAT TREATMENT OF IRON-BASE ALLOYS D. S. Gnanamuthu and V. S. Shankar •

RESIDUAL STRESSES INDUCED BY LASER SURFACE TREATMENT C. Chabrol and A. B. Vannes ••••••••

LASER SURFACE MELTING AND ALLOYING OF TITANIUM

389

413

435

J. Folkes, D. R. F. West, and W. M. Steen. • •••••• 451

LASER SURFACE ALLOYING OF STAINLESS STEEL WITH CARBON C. Marsden, D. R. F. West, and W. M. Steen •• ••••••• 461

CARBURIZATION OF STEEL SURFACES BY LASER TREATMENT E. Ramous ••••••••••••••.•••• 475

RAPID SOLIDIFICATION OF SURFACE LAYERS MELTED BY CW LASER L. Giordano and E. Ramous • • • • • • • • • • • • • • • 483

LASER SURFACE TREATMENT FOR ELECTROMECHANICAL APPLICATIONS J. Com-Nougue and E. Kerrand .•.• • • • • • 497

EDITED QUESTIONS - CHAPTER 5 Bergmann, Steen, Mordike, Gnanamuthu, Folkes, Marsden, Ramous Kerrand • • • • • • • • • • • • • • • • • • • • • • •• 513

CHAPTER 6 - APPLICATION TO INDUSTRY

CHAPTER INTRODUCTION C. W. Draper ••

DEVELOPMENTS IN LASER MATERIAL PROCESSING FOR THE AUTOMOTIVE INDUSTRIES

. •• 519

A. V. La Rocca ••••••.••.•••••.••••• 521

THE USE OF LASERS IN ROLLS-ROYCE R. M. Macintyre •••••

EDITED QUESTIONS - CHAPTER 6

545

La Rocca, Mcintyre • • • • • • • . • • • • • • • • • • • • •• 551

CHAPTER 7. LASER SURFACE CHEMISTRY

CHAPTER INTRODUCTION J. Tardieu de Maleissye

LASER-INDUCED DECOMPOSITION OF MOLECULES RELATED TO PHOTOCHEMICAL DEPOSITION

XIX

• 553

J. Tardieu de Maleissye • • • • • • • • • • • • • • • • • •• 555

METAL FILM DEPOSITION BY LASER BREAKDOWN CHEMICAL VAPOR DEPOSITION Thomas R. Jervi s ••••••••••••••••••••••• 567

COMBINED USE OF LASER IRRADIATION AND ELECTROPLATING J. R. Roos, J. P. Celis, W. Van Vooren •••••

EDITED QUESTIONS - CHAPTER 7

577

Tardieu de Maleissye, Jervis, Celis. • • • • • . • • • • • •• 591

CHAPTER 8 - LASER ANNEALING OF SILICON

CHAPTER INTRODUCTION J. M. Poate, P. S. Peercy, and S. U. Campisano

LASER ANNEALING OF SILICON J. M. Poate •••••.••••••

MEASUREMENT OF MELT AND SOLIDIFICATION DYNAMICS DURING PULSED LASER IRRADIATION

595

597

P. S. Peercy •••••.•••••••••••••••• 611

IMPURITY SEGREGATION, SUPERSATURATION AND INTERFACE STABILITY S. U. Campisano • • • • • • • • • • • • • • • • • • • • • • 639

MODELING AND MEASUREMENTS OF SOLUTE TRAPPING M. J. Aziz ••••••••••

EDITED QUESTIONS - CHAPTER 8 Poate, Peercy, Campisano, Aziz

CLOSING COMMENTS AND PHOTO HISTORY

649

663

C. W. Draper. P. Mazzo1di. and L. G. Dona da11e Rose ••••• 665

INDEX • • .'. 679