Ceramic Technology and Processing, King

Copyright © 2002 by Noyes Publications

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Library of Congress Catalog Card Number: 00-023980 ISBN: 0-8155-1443-3

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NOTICE

To the best of our knowledge the information in this publication is accurate; however the Publisher does not assume any responsibility or liability for the accuracy or completeness of, or consequences arising from, such information. This book is intended for informational purposes only. Mention of trade names or commercial products does not constitute endorsement or recommendation for use by the Publisher. Final determination of the suitability of any information or product for use contemplated by any user, and the manner of that use, is the sole responsibility of the user. We recommend that anyone intending to rely on any recommendation of materials or procedures mentioned in this publication should satisfy himself as to such suitability, and that he can meet all applicable safety and health standards.

Library of Congress Cataloging-in-Publication Data

Ceramic technology and processing / by Alan G. King.

vi Series

HANDBOOK OF SPUTTER DEPOSITION TECHNOLOGY: by Kiyotaka Wasa and Shigeru Hayakawa

HANDBOOK OF THIN FILM DEPOSITION PROCESSES AND TECHNIQUES, Second Edition: edited by Krishna Seshan

HANDBOOK OF VACUUM ARC SCIENCE AND TECHNOLOGY: edited by Raymond L. Boxman, Philip J. Martin, and David M. Sanders

HANDBOOK OF VLSI MICROLITHOGRAPHY,Second Edition: edited by John N. Helbert

HIGH DENSITY PLASMA SOURCES: edited by Oleg A. Popov

HYBRID MICROCIRCUIT TECHNOLOGY HANDBOOK,Second Edition:by James J. Licari and Leonard R. Enlow

IONIZED-CLUSTER BEAM DEPOSITION AND EPITAXY: by Toshinori Takagi

MOLECULAR BEAM EPITAXY: edited by Robin F. C. Farrow

NANOSTRUCTURED MATERIALS: edited by Carl. C. Koch

SEMICONDUCTOR MATERIALS AND PROCESS TECHNOLOGY HANDBOOK: edited by Gary E. McGuire

ULTRA-FINE PARTICLES: edited by Chikara Hayashi, R. Ueda and A. Tasaki

WIDE BANDGAP SEMICONDUCTORS: edited by Stephen J. Pearton

Related Titles

ADVANCED CERAMICPROCESSING AND TECHNOLOGY, Volume 1:edited by Jon G. P. Binner

CEMENTED TUNGSTEN CARBIDES: by Gopal S. Upadhyaya

CERAMIC CUTTING TOOLS: edited by E. Dow Whitney

CERAMIC FILMS AND COATINGS: edited by John B. Wachtman and Richard A. Haber

CERAMIC TECHNOLOGY AND PROCESSING: by Alan G. King

CORROSION OF GLASS, CERAMICS AND CERAMIC SUPERCONDUCTORS: edited by David E. Clark and Bruce K. Zoitos

FIBER REINFORCED CERAMIC COMPOSITES: edited by K. S. Mazdiyasni

FRICTION AND WEAR TRANSITIONS OF MATERIALS: by Peter J. Blau

HANDBOOK OF CERAMIC GRINDING AND POLISHING: edited by Ioan D. Marinescu, Hans K. Tonshoff, and Ichiro Inasaki

HANDBOOK OF HYDROTHERMAL TECHNOLOGY: edited by K. Byrappa and Masahiro Yoshimura

HANDBOOK OF INDUSTRIAL REFRACTORIES TECHNOLOGY: by Stephen C. Carniglia and Gordon L. Barna

MECHANICALALLOYINGFORFABRICATIONOFADVANCEDENGINEERINGMATERIALS: by M. Sherif El-Eskandarany

SHOCK WAVES FOR INDUSTRIAL APPLICATIONS: edited by Lawrence E. Murr

SOL-GEL TECHNOLOGY FOR THIN FILMS, FIBERS, PREFORMS, ELECTRONICS AND SPECIALTY SHAPES: edited by Lisa C. Klein

SOL-GEL SILICA: by Larry L. Hench

SPECIAL MELTING AND PROCESSING TECHNOLOGIES: edited by G. K. Bhat

SUPERCRITICAL FLUID CLEANING: edited byJohn McHardy and Samuel P. Sawan

IN MEMORIAM

Alan G. King

1924–2000

Alan G. King, a Member Emeritus of the American Ceramic Society, passed away on October 14, 2000. The manuscript for this book was nearing completion at the time of his death, and Anthony King, his son, finished assembling the pages as a testament to Alan’s illustrious career.

Mr. King served in the Army during World War II. After the war, he attended the University of Utah, obtaining a Bachelor’s degree in Geology and a Master’s in Mineralogy.

In 1985, Alan received the first Technical Achievement Award as chairperson of the Advanced Ceramics Task Force which provided focused direction in the field of advanced ceramics to Ferro Corporation. He retired from there in 1991 as a group leader of the research and development division. His career produced almost a dozen patents in the field of ceramic cutting tools.

viii InPrefaceMemoriam

His long and productive association with the American Ceramic Society was appreciated. In 1975, Alan became a Fellow of the Society in recognition of his many notable contributions to the ceramics arts and industry; in 1991, he became a Member Emeritus for more than thirty-five years of dedicated service.

Alan maintained a laboratory in his home’s basement and wrote technical bulletins and manuals as well as the manuscript for this book. He previously authored the book, Ceramics in Machining Processes, published in 1966 by Academic Press.

Foreword

This book is arranged in chapters that parallel the ceramic processing and analytical procedures. Up front are discussions on experimental design and laboratory safety. Following this sequentially, are the steps for: mixing, milling, slip preparation, mixing coarse-grained materials, forming, green machining, firing, and machining. The final presentation is the effect of pro-cessing on properties and property measurements. It is difficult to keep up with instrumentation as this changes so fast. One will find parts of this book a little out-of-date, by a couple of years. Fortunately, ceramics is a mature technology with the essentials moving slowly.

Each step in the manufacturing process has attendant problems associated with it. Along with these problems are measures to reduce them. Some typical problems are particle segregation, agglomeration, contamination, pressure gradients, adherence to tooling, and temperature gradients during drying and firing.

Emphasis is on the practicality of doing these operations in the ceramic laboratory; this limits the batch size. A one-to-one correlation between laboratory experiments and production scale experiments is tenuous at best. These differences occur naturally because of differences in scale and differences in the equipment used. Heat transfer through a small body is faster than through a large one. Shear during mixing is different in a bench

Hobart than it is in a large Eirich. Pressure gradients in a laboratory coupon during pressing are different from those in a 18" x 24" x 1.5" slab. In spite of these differences, the same principles and techniques apply, with due recognition to scale.

Once the laboratory work has been completed to a reasonable conclusion, there is the serious problem of technology transfer to a manufacturing plant and sequentially to the customer. The overwhelming problem with technology transfer is the allocation of human and capital resources. Because of risks with anything new, management usually starts small to test the market. Customers are often restrained by similar considerations and will not readily accept, or even test, a new product. For example, a new glass pigmentation system was developed that showed promise. In order for a customer to test the new system, he had to risk an entire glass tank batch, with the subsequent clean out, refractory failure, production lost, and compromis-ing good relations with his customers. He declined to do the test. A substantial risk reduces the chances of running a test. However, this is another subject and not within the scope of this book, but perhaps deserving of another volume.

Each section has practical hands-on suggestions on performing and sometimes avoiding certain tasks. There are many drawings and photographs that illustrate both the equipment and the accompanying procedures; the author has experience with the illustrated equipment. This does not preclude that a better choice might be made, especially since instrumentation is developing so rapidly. The intent of this book is to bring to the reader information that is not, or is sparsely available, to people working in our industry.

Laboratory skills are gained by hands-on experience. The intent of this book is to accelerate this process.

Preface

Not long ago, I met a scientist who earned his Ph.D. degree, from a well-recognized university, in materials science (ceramics). During the course of conversation, this scientist mentioned to me that when he started to work in industry he had to acquire additional information to do the job. This declaration should shock many people, as it did me. After six to eight years of advanced education, it appeared that this scientist had not acquired enough information to do his job. Sadly, this is not an isolated case. Many companies, in a variety of industries, have encountered this problem. It will be constructive to try to understand this gap in training, specifically in ceramics. There are three main reasons that can account for this situation.

Firstly, ceramics is considered a technology and not a science. In that most properties of ceramic materials are predictable only from experience and not from theory. Kingery`s book, An Introduction to Ceramics, marked a turning point in ceramic education with an emphasis on the underlying scientific principles. This text, along with subsequent texts by other authors with a similar mind set, is widely used throughout academia. This trend toward teaching ceramics science is indisputably laudable, but in some respects may have introduced a problem of exclusion. The interval within which a student can be subjected to bondage has both practical and humane limits. A student cannot possibly learn all the

essentials needed even within the confines of materials science, let alone the laboratory crafts. So, there has to be a knowledge gap.

Secondly, scientific and engineering journals have severe restrictions on page space. The volume of papers submitted for publication exceeds the space available for publication; this necessitates exclusion of some material. Anyone who has written a paper has experienced this compression. Editors expurgate or excise descriptions of procedures to the extent that one cannot duplicate the work since it lacks some necessary information. This phenomenon creates a knowledge gap.

Thirdly, industrial research is driven by economics; this is a demanding taskmaster. The ceramic engineer is always balancing on a tight rope with regard to the following: cost verses performance, engineering verses creativity, empiricism verses engineering, and time verses resolution of the problem. The complexity of essential needs mitigates against a formalized approach towards structured education. Competition drives performance up and prices down, with these often in conflict. In industry, there will be a wide variety of problems each of which has its own demands on technique that cannot possibly be comprehensively included in a curricula. This further induces a knowledge gap.

Anyone entering the ceramics field is confronted with the above problems. Thus, they need to learn a great deal about laboratory procedures that were not taught in school and are not available in the technical literature. Additionally, technicians without a formal education in ceramics are even worse off, as they have to start with the basics. Herein lies the problem that raises the need for a solution.

This book is a compilation of laboratory experiences in the sequential phases of ceramic processing and analysis. While not in the style of a hand-book, in a real sense, it is a guide and manual to some practical aspects excluded from other available sources. This exclusion created a problem where the author, by necessity, had to draw largely from his own experience. This experience-oriented work leaves us with some underrepresented areas and other over-represented areas. In the absence of an alternative, this book is written with the confidence that it is sufficiently comprehensive to be useful.

Is this a solution to the information gap in the curricula and technical literature? Of course not, but this is a start. With good fortune, this book will go into a second edition, in which case an expansion is possible