SUPERALLOYS, SUPERCOMPOSITES AND SUPERCERAMICS Edited by JOHN K. TIEN Center for Strategic Materials Columbia University New York, New York THOMAS CAULFIELD Philips Laboratories Briar cliff Manor, New York ACADEMIC PRESS, INC. Harcourt Brace Jovanovich, Publishers Boston San Diego New York Berkeley London Sydney Tokyo Toronto COPYRIGHT © 1989 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. 1250 Sixth Avenue, San Diego, CA 92101 United Kingdom Edition published by ACADEMIC PRESS INC. (LONDON) LTD. 24/28 Oval Road, London NW1 7DX Library of Congress Cataloging-in-Publication Data Superalloys, supercomposites, and superceramics/edited by John K. Tien, Thomas Caulfield. p. cm.—(Materials science and technology series) 1. Heat resistant alloys. 2. Ceramic materials. 3. Composite materials. I. Tien, John Κ. II. Caulfield, Thomas. III. Series: Materials science and technology. TA485.S95 1989 620.1'18-dc 19 88-30261 ISBN 0-12-690845-1 PRINTED IN THE UNITED STATES OF AMERICA 89 90 91 92 9 8 7 6 5 4 3 2 1 This volume is dedicated to Falih N. Darmara now of the Principality of Andorra and to Ν. N. Hsu late of Taipei Contributors Numbers in parentheses refer to the pages on which the authors' contributions begin. STEPHEN D. ANTOLOVICH (363), Georgia Institute of Technology, School of Materials Engineering, Mechanical Properties Research Laboratory, Atlanta, Georgia 30332-0245 N. BIRKS (439), Metallurgy and Materials Science Department, University of Pittsburgh, Pittsburgh, Pennsylvania WILLIAM BOESCH (1), Special Metals Corporation, 16 Lin Road, Utica, New York 13501 JANINE C. BOROFKA (237), Center for Strategic Materials, Henry Krumb School of Mines, Columbia University, 520 W. 120th Street, New York, New York 10027 G. K. BOUSE (99), Howmet Turbine Components Corporation, Whitehall Technical Center, 699 Benston Road, Whitehall, Michigan 49461 THOMAS CAULFIELD (625), Philips Laboratories, 345 Scarborough Road, Briar cliff Manor, New York 10510 WILLIS T. CHANDLER (491), Rockwell International, Rocketdyne Division, 6633 Canoga Avenue, Canoga Park, California 91303 C. I. CHEN (721), Materials R&D Center, Chung Shan Institute of Science and Technology, Lungtan, Taiwan WILFORD H. COUTS, Jr. (183), Wyman-Gordon Company, Worcester, Massa chusetts B. J. DALGLEISH (697), Materials Department, College of Engineering, Univer sity of California, Santa Barbara, California 93106 DAVID N. DUHL (149), Pratt & Whitney, Engineering Division—North, 400 Main Street, East Hartford, Connecticut 06108 A. G. EVANS (697), Materials Department, College of Engineering, University of California, Santa Barbara, California 93106 xv xvi Contributors LESLIE G. FRITZEMEIER (491), Rockwell International, Rocketdyne Division, 6633 Canoga Avenue, Canoga Park, California 91303 TIMOTHY E. HOWSON (183), Wyman-Gordon Company, Worcester, Massa chusetts S. E. Hsu (721), Materials R&D Center, Chung Shan Institute of Science and Technology, Lungtan, Taiwan ELIZABETH G. JACOBS (285), Center for Strategic Materials, Columbia Univer sity, 520 W. 120th Street, New York, New York 10027 R. NATHAN KATZ (671), U.S. Army Materials Technology Laboratory, 405 Arsenal Street, Water town, Massachusetts 02172 Β. H. KEAR (545), Department of Mechanics and Materials Science, Rutgers University, Piscataway, New Jersey ROBERT D. KISSINGER (237), Engineering Materials, Technology Laborator ies, General Electric Company, Cincinatti, Ohio MASAKI KITAGAWA (413), Metallurgy Department, Research Institute, Ishik- awajima-Harima Heavy Industries Co., Ltd., 1-15 Toyoshu 3-chome, Koto-ku, Tokyo 135, Japan G. L. LEATHERMAN (671), Mechanical Engineering Department, Worcester Polytechnic Institute, Worcester, Massachusetts 01609 BRAD LERCH (363), Georgia Institute of Technology, School of Materials Engineering, Mechanical Properties Research Laboratory, Atlanta, Georgia 30332-0245 C. T. Liu (583), Metals and Ceramics Division, Oak Ridge National Labora tory, PO Box X, Oak Ridge, Tennessee 37831-6115 GERNANT E. MAURER (49), Special Metals Corporation, Middle Settlement Road, New Hartford, New York 13413 G. H. MEIER (439), Metallurgy and Materials Science Department, University of Pittsburgh, Pittsburgh, Pennsylvania J. R. MIHALISIN (99), Howmet Turbine Components Corporation, Dover Alloy Division, Dover, New Jersey 07801 YOSHIO MONMA (339), National Research Institute for Metals (NRIM), Tokyo 153, Japan S. V. NAIR (301), Department of Mechanical Engineering, University of Massachusetts, Amherst, Massachusetts 01003 V. C. NARDONE (301), United Technologies Research Center, Mail Stop 24, Silver Lane, East Hartford, Connecticut 06108 DONALD W. PETRASEK (625), National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135 F. S. PETTIT (439), Metallurgy and Materials Science Department, University of Pittsburgh, Pittsburgh, Pennsylvania D. P. POPE (545, 583), Department of Materials Science and Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6272 Contributors xvii J. M. SANCHEZ (525), Center for Strategic Materials, Columbia University, 520 W. 120th Street, New York, New York 10027 ROBERT A. SIGNORELLI (625), National Aeronautics and Space Administra tion, Lewis Research Center, Cleveland, Ohio 44135 JOSEPH R. STEPHENS (9), National Aeronautics and Space Administration, Lewis Research Center, Cleveland, Ohio 44135 MANABU TAMURA (215), Steel Research Center, Nippon Kokan Κ. K., Kawasaki, Japan JOHN K. TIEN (237, 285, 301, 525, 625), Center for Strategic Materials, Henry Krumb School of Mines, Columbia University, 520 W. 120th Street, New York, New York 10027 N. C. Tso (525), Center for Strategic Materials, Columbia University, 520 W. 120th Street, New York, New York 10027 Preface Progress in such strategic applications as jet engines, turbine power generators, rockets and missiles is rate controlled by the development of structural materials with ever higher temperature capabilities and reliability. For the past forty years, superalloys have been the core material system fulfilling such needs. Much has been learned through the years and super- alloys have gone through many process advances—from air melting to vacuum melting and refining, and onto double vacuum melting, directional structural manipulation and extra ultra-clean alloys. Cast components are now enjoying not only higher yield, precision vacuum investment shaping and coring, but also the extra heat resistance benefits derived from directional heat extraction and the resulting directionally solidified grain structures, monocrystals, and more recently dense, clean and fine-grained structures that may begin to compete with wrought superalloys. Although the demand for superalloys, and, in general, the applications for superalloys have grown, servicable high temperature limits for superalloys, even with cooling schemes, are fast approaching. Accordingly, research and development in alternative high temperature systems is and has been in full swing for some time now. Such systems, like ODS and fiber reinforced superalloys (FRS), can be considered direct derivatives of superalloy tech nology. The aim of this volume is to review the state of superalloy technology and concurrently cover some of the more salient aspects of alternative high temperature systems such as superceramics and supercomposites. The no menclature superceramic and supercomposite has been adopted from the use of super to describe high temperature, structural alloys, i.e. superalloys. In other words, we have extended the use of the prefix super to classify high temperature, structural ceramic and composite systems. We have asked the key players in the field to contribute chapters to this volume. To this end the Table of Contents reads like a who's who in high temperature materials. By no means do we intend for this volume to offer an exhaustive review of the entire field. It does, however, address what we believe to be the key issues of high temperature materials in a synergistic manner. Superalloy topics range from resource availability, to discussions on ad vanced processing such as VIM, VAR, VADAR, investment casting and xix XX Preface single crystal growth, new superplastic forming techniques and powder metallurgy (including HIP), to structure property relationships, important strengthening mechanisms, oxidation, hydrogen embrittlement and phase predictions. The alternative high temperature systems chapters cover inter- metallics, fiber reinforced superalloys, and the processing and high tempera ture properties of ceramics and C/C systems. Since high temperature materials are no longer restricted to the confines of the U.S.A., the book contains many contributions from the far east. There are many people, mostly graduate students, to whom we are grateful for their help in preparing this manuscript. It is impossible to thank them all here, but their contributions do not go unnoticed. We are very appreciative of the technical assistance given to us on many of the chapter contributions by Dr. Edward Stover and Dr. Robert Kane. Their help has been invaluable. We would also like to thank Mr. Robert Kaplan and his entire staff at Academic Press for their efforts in publishing this text. Finally, we are most proud to dedicate this volume to two distinguished leaders in material research; Falih N. Darmara, the superalloy pioneer, and for over forty years of outstanding contributions to superalloy development and processing, and Ν. N. Hsu for his devoted service and pioneering leadership in high temperature materials development in the far east. Unfortunately, the untimely death of Dr. Hsu prevented the completion of his chapter contribution. John K. Tien Thomas Caulfield New York, April 1988 Foreword It is a most unforeseen honor to be asked to write the foreword to the volume Superalloys, Supercomposites and Superceramics. This sign of esteem from my colleagues is specially touching as there are so many familiar names of former co-workers among the contributors. As I sit writing these lines there is in front of me one memento that seems particularly appropriate. The inscription on the plaque is Cross Section of J-48 Turbine Blade. Heat AA-28 The World's First Production Heat of Vacuum Melted High Temperature Alloy. Melted December 31, 1952. This particular heat of Waspalloy was the product of a six pound furnace! The data is significant in that it is only thirty-six years old. Who could have been brave enough in those days to prophesy not just the quantitative leap in the volume of superalloys produced but the immense qualitative improve ments in the properties of these alloys, the development of new and more powerful investigative tools and the concomitant advances in our knowledge of the laws controlling these properties. The improvements in the properties led to increases in the efficiency and power of the engines that used these materials. Consider the J-48 for which the above mentioned heat of Waspaloy was made. If memory serves me right, it was the first autonomously designed engine by Pratt & Whitney and was a direct descendant of the Whittle engine. It had a centrifugal compressor and very large forged turbine blades of Waspaloy. This alloy had been developed by Rudy Thieleman then at Pratt & Whitney specifically for the J-48. This relatively inefficient and clumsy engine could not have developed more than three or four thousand pounds of thrust. The fuel efficiency was atrocious and the blade life was at most a thousand hours. This particular engine-alloy combination played a most seminal role in the development of superalloy production. It may be worthwhile recounting the occurrence as it may prove amusingly instructive to the younger and nostalgic to the older generation. However before proceeding with that, it is xxi xxii Foreword instructive to delve into the history of events up to that time. The advent of the jet engine introduced an entirely new element in the attributes desirable in either cast or wrought heat resistant alloys. Except for steam turbines and turbocompressors for military piston engines, other uses were for stationay applications, and weight-to-strength ratio at high temperature was not critically important. But even in steam sturbines as they did not fly, lack of creep resistance in the blading material could be compensated for by increasing the cross section and reducing the stress. The only even remotely comparable requirement to that of a jet engine was the turbo-compressor. But even here the weight involved and the relatively low temperature of operation did not set too high a priority on the strengths required. Most of the wrought alloys used as heat resistant steels were Fe-Cr or Fe- Cr—with some moly, or 300 series stainless steels, containing Ni in the matrix. Alloys 321 Ti and 347 Cb were added but only for the purpose of stabilizing the carbides, and so, were added as a multiple of the carbon content. In some of the early Ni-Cr-Fe alloys the matrix composition was modified by the addition of Co, and in some cases, varying amounts of W or Mo. The one set of alloys that are in a class by themselves and were used for a short period around 1944 as forged blades are the Hastalloy's. These, of course consist of a Ni matrix with up to 30% Mo and no Cr, and hence exhibit little high temperature oxidation resistance. This writer remembers vividly the sight of a whole batch of forged blades reduced to brown cardboard that, as a struggling heat treat metallurgist, he had ruined. The only alloys that were precipitation hardened were Inconel Χ, K-42-B, and Refractoloy 26. The preciptation mechanism was provided by the varying amounts of Ti and Al which they contained. Inconel X was no doubt a relative of the Nimonic series. Since the first was produced by Inco in the U.S. and the other by Wiggin, an Inco subsidiary, in England. To this writer it appears that most present day superalloys are direct descendants of these alloys. The first Jet engine brought to this country was one of the Whittle engines. The task of designing an American version was given to General Electric (Schenectady) since GE had a great deal of experience in the design and construction of turbo compressors and turbines in general. The first engine to issue from GE was the 1-40, in 1943-44. It was quite similar to the J-48 in design, both being direct offsprings of the Whittle engine. The turbine blades were forged from S-816, an alloy developed by Dr. Gunther Mohling at the Watervliet plant of Allegheny Ludlum Co. and only a stone's throw from Schenectady. The matrix was Cr-Ni-Co with additions of Mo-W-Cb and fairly high carbon. The composition was easy to remember 20-20-20-4-4-4 with C0.40. The heat treatment involved a soak at the high temperature of 1260°C followed by a water quench and then aged 50 hours at 732-815°C. It was obviously carbide strengthened.