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Ultrarapid Quenching of Liquid Alloys PDF

453 Pages·1981·13.769 MB·English
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TREATISE EDITOR HERBERT HERMAN Department of Materials Science and Engineering State University of New York at Stony Brook Stony Brook, New York ADVISORY BOARD J. W. CHRISTIAN, F.R.S. P. B. HIRSCH, F.R.S. Oxford University Oxford University Oxford, England Oxford, England Μ. E. FINE R. I. JAFFEE Northwestern University Electric Power Research Institute Evanston, Illinois Palo Alto, California J. FRIEDEL Ε. I. SALKOVITZ Universite de Paris U.S. Office of Naval Research Orsay, France Arlington, Virginia A. GOLAND A. SEEGER Department of Physics Max-Planck-Institut Brookhaven National Laboratory Stuttgart, Germany Upton, New York J. J. HARWOOD J. B. WACHTMAN Ford Motor Company National Bureau of Standards Dearborn, Michigan Washington, D.C. TREATISE ON MATERIALS SCIENCE AND TECHNOLOGY VOLUME 20 ULTRARAPID QUENCHING OF LIQUID ALLOYS EDITED BY 1981 ACADEMIC PRESS A Subsidiary of Harcourt Brace Jovanovich, Publishers New York London Paris San Diego San Francisco Sao Paulo Sydney Tokyo Toronto COPYRIGHT © 1981, BY ACADEMIC PRESS, INC. ALL RIGHTS RESERVED. NO PART OF THIS PUBLICATION MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM OR BY ANY MEANS, ELECTRONIC OR MECHANICAL, INCLUDING PHOTOCOPY, RECORDING, OR ANY INFORMATION STORAGE AND RETRIEVAL SYSTEM, WITHOUT PERMISSION IN WRITING FROM THE PUBLISHER. ACADEMIC PRESS, INC. Ill Fifth Avenue, New York, New York 10003 United Kingdom Edition published by ACADEMIC PRESS, INC. (LONDON) LTD. 24/28 Oval Road, London NW1 7DX LIBRARY OF CONGRESS CATALOG CARD NUMBER: 77-182672 ISBN 0-12-341820-8 PRINTED IN THE UNITED STATES OF AMERICA 81 82 83 84 9 8 7 6 5 4 3 2 1 List of Contributors Numbers in parentheses indicate the pages on which the authors' contributions begin. H. S. CHEN (215), Bell Laboratories, Murray Hill, New Jersey 07974 KOJI HASHIMOTO (291), The Research Institute for Iron, Steel, and Other Metals, Tohoku University, Sendai, Japan HERBERT HERMAN (183), Department of Materials Science and Engineer­ ing, State University of New York at Stony Brook, Stony Brook, New York 11794 R. W. K. HONEYCOMBE (117), Department of Metallurgy and Materials Science, University of Cambridge, Cambridge, United Kingdom K. A. JACKSON (215), Bell Laboratories, Murray Hill, New Jersey 07974 H. JONES (1), Department of Metallurgy, University of Sheffield, Sheffield SI 3JD, United Kingdom MARIA LASOCKA (261), Institute of Materials Science and Engineering, Warsaw Technical University, Warsaw, Poland J. C. M. Li (325), Department of Mechanical Engineering, University of Rochester, Rochester, New York 14627, and Institut fur Werkstoffe, Ruhr Universitat Bochum, D-4630 Bochum-1, West Germany J. LIVAGE (73), Laboratoire de Chimie Appliquee de TEtat Solide, Ecole Nationale Superieure de Chimie de Paris, Paris, France ix χ LIST OF CONTRIBUTORS TSUYOSHI MASUMOTO (291), The Research Institute for Iron, Steel, and Other Metals, Tohoku University, Sendai, Japan HENRYK MATYJA (261), Institute of Materials Science and Engineering, Warsaw Technical University, Warsaw, Poland A. REVCOLEVSCHI (73), Laboratoire de Chimie Appliquee, Universite de Paris-Sud-Bat. 414, 91405 Orsay, France SAED SAFAI (183), Pratt and Whitney Aircraft Group, United Technolo­ gies, West Palm Beach, Florida 33402 C. C. TSUEI (395), IBM Thomas J. Watson Research Center, Yorktown Heights, New York 10598 J. V. WOOD (117), Faculty of Technology, The Open University, Walton Hall, Milton Keynes MK7 6AA, United Kingdom Foreword Materials limitations are often the major deterrents to the achievement of new technological advances. In modern engineering systems, materials scientists and engineers must continually strive to develop materials that can withstand extreme environmental conditions and maintain their required properties. In the recent past we have seen the emergence of new types of materials, literally designed and processed with specific uses in mind. Many of these materials and the advanced techniques that were developed to produce them came directly or indirectly from basic scien­ tific research. The "Treatise on Materials Science and Technology" is dedicated to the relationship between the science and utility of materials. There can be no better example of this relationship than that represented by this twentieth volume of the treatise: "Ultrarapid Quenching of Liquid Metals." Based on research started in the late 1950s, this field has cap­ tured the imaginations of many scientists and engineers, giving rise to hundreds of publications and numerous patents and industrial activities. Embodied in rapid solidification science and technology is the essence of innovational thrusts upon which the future will depend. It is our hope that this volume as well as other volumes of this treatise will assist in the growth of such new materials activities. H. HERMAN xi Preface When, in the distant future, histories are written on the origins of mate­ rials processing, the relatively recent developments in ultrarapid solidifi­ cation will most likely receive considerable attention. In fact, today's rapid solidification technology originates from the eiforts of metallurgists to trap highly metastable states through super-fast quenching of bulk al­ loys. It was not so many years ago that five-figure cooling rates were viewed as the upper limits, using, for example, cold-helium gas quench­ ing, in a vacuum, of an electrically heated solid foil or wire specimen. Of course, vapor phase quenching has been used, and remains important, but, generally, physical vapor deposition techniques yield very thin specimens. It was Duwez and co-workers who, some 20 years ago, recognized that the key to ultrarapid quenching depends on good physical contact be­ tween the material and a low temperature, highly conductive substrate. Effective and rapid contact was deemed essential. So, instead of quench­ ing a solid, they proceeded to quench molten alloys. Thus was born liquid quenching or splat cooling, both terms being apt descriptions of what is becoming a major industrial process. In the past few years the field of liquid quenching has seen hundreds of publications on techniques of quenching, property measurements, and industrial applications. A number of metal alloy systems have been formed in amorphous condition through rapid solidification. Subsequent studies are leading to both empirical criteria and theoretical understanding for the bases upon which amorphous metals can be formed. Such studies have indeed led to a number of industrial products based on special, and sometimes unique, mechanical, electrical, and magnetic properties. More recently, chemical properties of these unique materials have received considerable attention. In a field as active as rapid liquid quenching, covering so wide a range of materials science, reviews can play an important role. This volume was xiii xiv PREFACE developed to enable an overview of certain prominent aspects of this field. Jones, in his chapter, conveys a historical perspective, reviewing the varieties of methods that have evolved for producing rapidly solidified materials. He examines the criteria for the formation of highly metastable states and how these relate to experiment. Rapid solidification of nonmet- als is examined by Revcolevschi and Livage, who explore the limited though exciting experiences in this evolving area. And the industrial imp­ lications of rapid solidification of iron-based alloys become obvious in the chapter by Wood and Honeycombe. In their chapter on plasma spraying, Safai and Herman emphasize the utility of this industrial process for producing rapidly solidified ceramics and metallic alloys. While this and allied techniques have formerly been used principally to create protective coatings, it is suggested that thermal spraying may indeed have a future role to play in rapid solidification technology. Metallic glasses have excited the imaginations of researchers and indus­ trialists alike. Chen and Jackson review this rapidly evolving field. Lasocka and Matyja examine what is known about annealing effects, and Hashimoto and Masumoto explore corrosion behavior of this new class of materials. The mechanical properties of the metallic glasses are reviewed by Li, who relates the similarities and surprises that are encountered in such studies. And finally, Tsuei examines what is known about the electri­ cal properties of rapidly solidified materials. An overall view of this field conveys excitement, surprise, and mul- tidisciplinary aspects shared by few scientific activities. There is much of the same ahead. It is hoped that this volume will contribute to the further growth and expansion of rapid solidification science and technology. TREATISE ON MATERIALS SCIENCE AND TECHNOLOGY, VOL. 20 1 Experimental Methods in Rapid Quenching from the Melt H. JONES Department of Metallurgy University of Sheffield Sheffield, United Kingdom I. Introduction 1 II. Historical Survey 3 III. Survey of Methods for Rapid Quenching from the Melt 7 A. Spray Methods 7 B. Chill Methods 16 C. Weld Methods 22 D. Factors Governing Choice of Method 26 IV. Cooling and Freezing 28 A. Predictions for Cooling and Freezing 29 B. Comparison with Experiment 33 V. Product Formation 37 A. Energetic Considerations 38 B. Effects of Cooling and Solidification 40 C. The Magnitude of Heat Transfer Coefficients 41 D. Some Considerations in Weld Methods 43 VI. Microstructure 45 A. General Features 46 B. Theory Compared with Experiment 47 C. Decomposition following Solidification 53 D. Quenching Efficiency 55 VII. Conclusion 58 List of Symbols 60 References 62 I. Introduction Rapid quenching, molecular deposition, and external action are the three basic alternative routes for achieving a nonequilibrium constitution or a remorphologized or refined microstructure in a material. Copyright © 1981 by Academic Press, Inc. All rights of reproduction in any form reserved. ISBN-0-12-341820-8 2 Η. JONES External action, for example, by deformation, irradiation, or chemical attack on solids, is very specific in its effects for particular materials and is outside the scope of the present volume. Molecular deposition includes formation from the vapor phase either by thermal evaporation or sputtering, or by chemical reaction (e.g., CVD),t or from salt solution by electroless displacement or electrodeposition. Although widely applicable, it has limitations both in terms of production rate and of energy efficiency. Rapid quenching normally involves a rapid decrease of temperature, fully or partially retaining the high-temperature structure, or else substan­ tially refining the scale of any transformation products that do result. Important limitations of the normal practice of quenching entirely within the solid state are the highly specific initial structure and the difficulty of achieving good contact with an effective heat sink, such as the surface of a highly conducting solid chill, during the quench. Rapid quenching from the melt (RQM), on the other hand, retains the main merit of molecular deposition in significantly extending the range of starting compositions that are not phase separated, while also generating a wide range of possible product geometries at high throughputs and quenching rates (through both liquid and solid phases) and with a much lower energy consumption. The high cooling rate imposed by RQM plays crucial roles in (a) promoting the increased supercooling necessary for large departures from equilibrium, (b) achieving rapid completion of so­ lidification:!: required, for example, to refine dendritic structures, and (c) ensuring suppression of decomposition during cooling through the solid state. Basic requirements for a high cooling rate in RQM are the rapid formation of a thin layer or small particle of the melt in good contact with an effective heat sink. Cooling rates in normal solidification processing both for large-scale industrial production of standard castings, ingots, and strands and for laboratory-scale steady-state solidification, are typically in 3 the range 10~ to 10°°K/s. Especially large sand castings and ingots freeze 6o at cooling rates as low as 10" K/s, while thin strip, rod, and die casting 3o can involve characteristic cooling rates as high as 10 K/s. The present concern is primarily with methods for achieving cooling rates approaching 6o or above 10 K/s during the solidification process and includes such di­ verse approaches as gas cooling or spray deposition of atomized liquid droplets, high-rate production of thin filaments or ribbons direct from the melt, as well as rapid surface melting followed by rapid solidification as given for example by a traversing laser or electron beam. t Chemical vapor deposition—for a recent review, see Bryant (1977). φ Rapid solidification processing (RSP) is thus a particularly important outcome of the rapid quench.

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