R E F R A C T O R Y A SERIES OF M A T E R I A L S MONOGRAPHS John L Margrave, Editor DEPARTMENT OF CHEMISTRY RICE U N I V E R S I T Y , HOUSTON, TEXAS VOLUME L R M c C r e i g h t , H W R a u c h , Sr., and W H Ceramic and Graphite Fibers and Whiskers A Survey of the VOLUME Edmund K Sutton Technology Storms The Refractory Carbides VOLUME H W R a u c h , Sr., W H S u t t o n , and L R M c C r e i g h t Ceramic Fibers and Fibrous Composite Materials VOLUME and H a r o l d B e r n s t e i n Computer Calculation of Phase Diagrams Larry Kaufman With Special Reference VOLUME Allen VOLUME Allen to Refractory Metals M A l p e r , Editor High Temperature Oxides Part I: Magnesia, Lime, and Chrome Refractories Part II: Oxides of Rare Earths, Titanium, Zirconium, Hafnium, Niobium, and Tantalum Part III: Magnesia, Alumina, Beryllia Ceramics: Fabrication, Character ization, and Properties Part IV: Refractory Glasses, Glass-Ceramics, and Ceramics M A l p e r , Editor Phase Diagrams: Materials Science and Technology Volume I: Theory, Principles, and Techniques of Phase Diagrams Volume II: The Use of Phase Diagrams in Metal, Refractory, Ceramic, and Cement Technology Volume III: The Use of Phase Diagrams in Electronic Materials and Glass Technology Volume IV: The Use of Phase Diagrams in Technical Materials Volume V: Crystal Chemistry, Stoichiometry, Spinodal Decomposition, Properties of Inorganic Phases VOLUME Louis Ε T o t h Transition Metal Carbides and Nitrides PHASE DIAGRAMS Materials Science and Technology Edited by A L L E N M ALPER Director Chemical of Research GTE Sylvania, Towanda, and and Metallurgical Engineering Division Incorporated Pennsylvania VOLUME V Crystal Chemistry, Stoichiometry, Spinodal Decomposition, Properties of Inorganic Phases 1978 ACADEMIC PRESS N e w York San F r a n c i s c o A Subsidiary of Harcourt Brace Jovanovich, Publishers London COPYRIGHT © 1978, BY ACADEMIC PRESS, I N C 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 A C A D E M I C PRESS, I N C I l l Fifth Avenue, New York, New York 10003 United Kingdom Edition published by A C A D E M I C PRESS, I N C ( L O N D O N ) 24/28 Oval Road, London N W 7DX LTD Library of Congress Cataloging in Publication Data Main entry under title: Phase diagrams (Refractory materials, v 6) Includes bibliographical references CONTENTS: v Theory, principles, and techniques o f phase d i a g r a m s — v The use o f phase diagrams in metal, refractory, ceramic, and cement technology, [etc.] Phase diagrams I Alper, Allen M., Date ed QD503.P48 54Γ.363 76-15326 ISBN - - 5 - ( v ) PRINTED IN THE UNITED STATES OF AMERICA TO MY Irving UNCLE Frohlich for the profound influence he had in inspiring my career in science and technology by sharing with me the innovative work he has done in the field of plastics List of Contributor s Numbers in parentheses indicate the pages on which the authors' contributions begin S T BULJAN*(287) Ceramics D e p a r t m e n t , G T E Sylvania I n c o r p o r a t e d , Chemical and Metallurgical Division, T o w a n d a , Pennsylvania 18848 L A R R Y E D R A F A L L f (185), Materials R e s e a r c h L a b o r a t o r y and De p a r t m e n t of Materials Science and Engineering, The Pennsylvania State University, University P a r k , Pennsylvania 16802 H H E R M A N (127), D e p a r t m e n t of Materials Science, State University of N e w Y o r k , Stony Brook, N e w Y o r k 11794 Κ H J A C K (241), Wolfson R e s e a r c h G r o u p for High-Strength Materials, Crystallography L a b o r a t o r y , T h e University, N e w c a s t l e upon T y n e , England C M F J A N T Z E N } (127), D e p a r t m e n t of Materials Science, State University of N e w York, Stony Brook, N e w York 11794 R N K L E I N E R (287),Ceramics D e p a r t m e n t , G T E Sylvania Incorpo rated, Chemical and Metallurgical Division, T o w a n d a , Pennsylvania 18848 R E N E W N H A M (1), Materials Research L a b o r a t o r y , T h e Pennsyl vania State University, University Park, Pennsylvania 16802 * Present address: GTE Laboratories, 0 Sylvan Road, Waltham, Massachusetts f Present address: Lambda/Airtron, 200 East Hanover A v e n u e , Morris Plains, N e w Jersey 07950 ί Present address: University of Aberdeen, Department of Chemistry, Old Aberdeen, Scotland A B U E Present address: Coors Porcelain Company, 17750 32nd Avenue, 80401 ix Golden, Colorado χ LIST OF C O N T R I B U T O R S D E L L A M R O Y (185), Materials R e s e a r c h L a b o r a t o r y and D e p a r t m e n t of Materials Science and Engineering, T h e Pennsylvania State Uni versity, University Park, Pennsylvania 16802 R U S T U M R O Y (185), Materials Research L a b o r a t o r y and D e p a r t m e n t of Materials Science and Engineering, T h e Pennsylvania State Univer sity, University Park, Pennsylvania 16802 O T O F T S R E N S E N (75), Metallurgy D e p a r t m e n t , Ris0 National Laboratory, Denmark Foreword P e r h a p s no area of science is regarded as basic in so many disciplines as that c o n c e r n e d with phase transitions, p h a s e diagrams, and the phase rule Geologists, ceramists, physicists, metallurgists, materials scientists, chemical engineers, and chemists all m a k e wide use of phase separations and phase diagrams in developing and interpreting their fields N e w techniques, new theories, c o m p u t e r m e t h o d s , and an infinity of new materials h a v e created many problems and opportunities which were not at all obvious to early r e s e a r c h e r s Paradoxically, formal courses and m o d e r n , authoritative b o o k s have not been available to meet their n e e d s Since it is the aim of this series to provide a set of m o d e r n reference volumes for various aspects of materials technology, and especially for refractory materials, it was logical for Dr Allen Alper to u n d e r t a k e this n e w c o v e r a g e of " P h a s e Diagrams: Materials Science and T e c h n o l o g y " by bringing together research ideas and innovative a p p r o a c h e s from diverse fields as presented by active contributors to the research literature It is my feeling that this extensive and intensive t r e a t m e n t of phase diagrams and related p h e n o m e n a will call attention to the m a n y techniques and ideas which are available for use in the many materialsoriented disciplines JOHN L xi MARGRAVE Preface This volume is a continuation of the use of phase diagrams in the understanding and d e v e l o p m e n t of inorganic materials In order to create materials with properties that are required for specific applications, it is necessary to understand h o w to form the desired p h a s e s by controlling composition, t e m p e r a t u r e , a t m o s p h e r e , e t c Also, phase diagrams are useful in giving us insight in understanding h o w the created p h a s e s will change u n d e r different e n v i r o n m e n t s such as high t e m p e r a t u r e s , cycling t e m p e r a t u r e s , corrosive e n v i r o n m e n t s , and a t m o s p h e r i c changes (reduc ing, oxidizing, inert) This volume contains s o m e excellent articles by R E N e w n h a m , Delia and R u s t u m R o y , and L a r r y E Drafall on the relationship of phase diagrams to crystal chemistry that should be helpful to all material scien tists and engineers T h e field of spinodal decomposition has been ex tremely active in the last few y e a r s T h e contribution by C M Jantzen and H H e r m a n analyzes spinodal decomposition in metallic, halide, oxide, glasses, and geologic s y s t e m s This should be of importance to most scientists and engineers w h o are investigating metals and ceramics The p a p e r by O Toft S r e n s e n on nonstoichiometric p h a s e s should be of great value to material scientists and engineers w h o are studying oxide systems T h e use of p h a s e diagrams in ceramic s y s t e m s that relate to applications w h e r e energy saving is critical is discussed by Κ H J a c k , T Buljan, and R Kleiner R e c e n t d e v e l o p m e n t s in sialons are discussed by Κ H Jack T h e s e materials have very high potential as parts in turbine engines T h e cordierite and s p o d u m e n e s y s t e m s discussed by R Kleiner and T Buljan have excellent potential as h e a t - e x c h a n g e r materials T h e editor wishes to t h a n k G T E Sylvania for its assistance xiii Content s of Othe r Volume s Volume I : Theory, Principles, and Techniques of Phase Diagrams I II T h e r m o d y n a m i c s of Phase Diagrams Υ K Rao C o m p u t e r Calculations of Refractory Metal Phase Diagrams Larry Kaufman and Harold Bernstein III T h e M e t h o d s of Phase Equilibria Determination and Their Associated Problems J B MacChesney and P E Rosenberg IV Interpretation of Phase Diagrams H C Yeh V T h e U s e of Phase Diagrams in Solidification William A Tiller VI Phase Diagrams in High P r e s s u r e Research A Jayaraman and Lewis H Cohen VII Metastable Phase Diagrams and Their Application to GlassForming Ceramic S y s t e m s T P Seward, III Volume I I : The Use of Phase Diagrams i n M e t a l , Refractory, Ceramic, and Cement Technology I The Effect of Oxygen P r e s s u r e on Phase Relations in Oxide Sys tems Arnulf Muan XV xvi C O N T E N T S OF O T H E R V O L U M E S II T h e Relationship of P h a s e Diagrams to Constitution and Microstructure in Ceramic and C e r a m i c - M e t a l S y s t e m s James White III T h e U s e of Phase Diagrams in the D e v e l o p m e n t and U s e of Re fractories Hobart M Kraner IV T h e U s e of Phase Diagrams in Fusion-Cast Refractory Materials Research A M Alper, R C Doman, R N McNally, and H C Yeh V VI VII VIII Application of the P h a s e Rule to C e m e n t Chemistry F P Glasser Phase Diagrams in Extraction Metallurgy J Taylor Intermediate P h a s e s in Metallic P h a s e Diagrams Τ B Massalski and Horace Pops T h e U s e of Phase Diagrams in the Sintering of Ceramics and Metals D Lynn Johnson IX X and Ivan B Cutler P h a s e Diagrams and the H e a t T r e a t m e n t of Metals George Krauss and Joseph F Libsch T h e U s e of P h a s e Diagrams in the Joining of Metals A Prince Volume I I I : The Use of Phase Diagrams i n Electronic Materials and Glass Technology I II III T h e U s e of P h a s e Diagrams in Crystal G r o w t h J W Nielsen and R R Monchamp T h e U s e of the Phase Diagram in Investigations of the Properties of C o m p o u n d S e m i c o n d u c t o r s Μ B Panish Superconductivity and Phase Diagrams V F Zackay, M F Merriam, and Κ M Ralls 314 R Ν KLEINER A N D S Τ BULJAN A l 20 3- Fig 21 Cordierite content in M g O - A l - S i glasses devitrified at 1110°C (after Tirrell et al., 1961) ceramics, shows a vast variation of properties depending on those condi tions It is not always possible to distinguish the individual effects of such a variety of factors, which makes direct correlation and systematization of the literature data extremely difficult because of the lack of definition of all the necessary parameters Figure 21 is the M g O - A l S i ternary phase diagrams, showing cordierite bearing compositions obtained by devitrification of glasses (Tirrel et al, 1961), and Fig 22 illustrates the correlation of thermal expansion and composition at 50% S i cross section of the M g O - A l S i system (Buljan and Kleiner 1975) F r o m the results obtained and reported to date it appears that materials of lowest thermal expansion in the M g O · A · S i system are most likely to be found near the M g O · A · S i (2:2:5) composition representing stoichiometric cordierite Figure 22 also shows the correlation between the coefficient of thermal expansion and the liquidus temperature, where compositions with lower melting temperatures exhibit lower thermal expansions C o m p o u n d s with VI SILICATES FOR THERMAL SHOCK RESISTANT APPLICATIONS 315 Fig 22 Thermal expansion and liquidus temperature at 50% S i cross section of M g O - A l - S i system (after Buljan and Kleiner, 1975) lower melting points often have lower thermal expansions (Fig 23) Exceptions to this rule, however, are not u n c o m m o n (e.g., alkali halides) It has been stated before that the properties of bulk ceramics could vary strongly, depending on the raw materials, impurity content, and processing conditions These factors interact strongly and it is not always possible to 316 R Ν KLEINER A N D S Τ BULJAN 5CoO 3Alg0 CoO 3CoO 5Al20 Fig 23 Thermal expansion of compounds in the C a O - A l 20 system (after Austin, 1952) 600 800 1,000 1,200 1,400 1,600 1,800 Thermal expansion - 0 °C(ppm) Fig 24 Influence of presence of calcium oxide on thermal expansion of 2:2:5 cordierite ceramic sintered at 1375°C for 10 hr (after Fritsch and Buljan, 1975) determine their individual effects A few examples that follow are an illustra tion of the extent of the effects of impurities in raw materials and of processing conditions on the bulk thermal expansion of : : cordierite ceramics The presence of Ca, for example, in amounts as low as 200 p p m raises the bulk thermal expansion of cordierite ceramics considerably The correlation between calcium content and thermal expansion of cordierite bodies prepared from talc, clay, and alumina mixtures (2:2:5 composition) is given in Fig 24 for cordierite bodies fired at 1375°C for 10 hrs Results obtained at 1350°C are essentially the same VI SILICATES FOR THERMAL SHOCK RESISTANT APPLICATIONS 317 Fig 25 Effect of 5% CaO addition in the M g O - A l - S i system (after Osborn et al, 1954) Calcium oxide in a m o u n t s as high as - % reduces liquidus temperatures by over 50°C and results in a stable glass in the fired cordierite body (Fig 25) The solid lines of Fig 25 show a primary phase region surrounding cordierite in the M g O - A l S i ternary system Assuming a constant alumina content and extrapolating the position and temperature of the primary phase fields (dashed lines), the effect of 5% C a O on equilibrium in the M g O - A l - S i system may be estimated The appearance of the liquid, about 50°C lower in temperature, and the increased stability of the glass phase with calcium oxide tend to decrease the percentage of cordierite in the fired body It is not surprising then that materials of very similar composition, prepared under virtually the same conditions, often show different dilational properties This holds true in particular with cordierite ceramics prepared from clay-talc mixtures, the most c o m m o n precursor materials of commercial cordierite ceramics, which, being naturally occurring substances, could contain u p to % impurities However, even if material is prepared from relatively pure precursor materials, variations in thermal processing could result in a material having substantially different dilational properties The simplest example of the variation of thermal expansion, resulting from variation in phase assembly due to heat treatment, is a simple two-phase system glass cordierite (2:2:5) that was studied in a series of experiments by Buljan and Kleiner (1975) 318 R Ν KLEINER A N D S Τ BULJAN Thermal expansion - 0 °C (ppm) Fig 26 Thermal expansion and glass content in the (2:2:5) cordierite-glass system (after Buljan and Kleiner, 1975) The glass content was determined, using scanning electron microscopy, on polished and etched samples and by x-ray diffraction techniques Glass of cordierite composition has a relatively high thermal expansion coefficient of 3.6 χ 10" 6/°C or 3000 p p m between 25 and 800°C The thermal expansion is expected to be equal to the sum of the products of the thermal expansion of the individual phases and their respective volume fractions By varying the glass-cordierite ratio, using the appropriate heat treatment, it is expected that the thermal expansion of the obtained material would change as a linear function of the glass content The experimental results are shown in Fig 26, in which thermal expansion is plotted as a function of glass content It can be seen that the linear dependence is, in fact, observed on the high-glass content portion of the curve The thermal expansion value for 100% cordierite, obtained by extrapolation, is approximately 1160 p p m between 25 and 800°C The %(AV/V) value calculated, using lattice thermal expansion data obtained by Fisher et al (1974), is in good agreement with the extrapolated value from the diagram in Fig 26 Devia tion from linearity in the low-glass content portion of the curve, correspond ing to values of thermal expansion down to 400 ppm, far below the value for 100% cordierite, can be attributed to factors other than phase assembly, namely, microstructural parameters governing thermal expansion of polycrystalline ceramics Microstructural features other than phase assembly, such as presence of microcracks and preferential orientation of crystallites, have a strong influence on the dilational properties of cordierite ceramics and are highly dependent on processing and precursor materials Their VI SILICATES FOR THERMAL SHOCK RESISTANT APPLICATIONS 319 Microcrack frequency /i.rrf Fig 27 Thermal expansion as a function of average microcrack length and frequency Bodies with TE lower than 1000 ppm; Θ , bodies with TE higher than 1000 ppm Δ influence on bulk thermal expansion is very strong Figure 27 gives the rough correlation between thermal expansion and microcrack size, and density for : : cordierite ceramics Microcrack size and density were determined by analysis of S E M photomicrographs of polished and etched samples The dashed line indicates bodies with a thermal expansion of 1000 p p m be tween 25 and 800°C The mechanism of microcrack formation in cordierite ceramics is still not well defined However, results obtained to date indicate that the mech anism can be attributed to intercrystalline stresses resulting from the thermal expansion anisotropy of crystalline cordierite This effect could be exploited in order t o lower the bulk thermal expansion of cordierite ceramics Cordierite ceramics, having thermal expansions lower than that calculated from the lattice thermal expansion, and as low as 200 p p m between 25 and 800°C, a n d extraordinary thermal shock p r o p erties, have been prepared by controlled introduction of microcracks (Fritsch and Buljan, 1976) Such bodies exhibit an isotropic thermal expansion A choice of raw materials and processing methods could also result in an anisotropic polycrystalline aggregate because of the preferential orientation of cordierite crystallites This feature was used by L a c h m a n and Lewis (1975) to prepare an anisotropic cordierite monolith from delaminated kaolin and 320 R Ν KLEINER A N D S Τ BULJAN talc mixtures by extrusion The resulting bodies exhibit a low expansion in one plane and a higher thermal expansion in a direction perpendicular to this plane These few examples clearly show the extent of effects of impurities and microstructural parameters resulting from processing conditions, and illus trate the necessity and benefits of better understanding and control of factors influencing properties of bulk ceramics Further improvement of the thermal expansion properties of cordierite ceramics could come through a better understanding and a better definition of cordierite solid solution and polymorphism, and the possibility of modifying the lattice thermal expansion of cordierite, which, combined with an understanding of parameters gov erning thermal expansion of polycrystalline ceramics, could bring about substantial improvements of thermal shock properties necessary for heat exchanger applications The physical-chemical behavior of silicates is one of the most complicated problems in inorganic chemical research The a b u n d a n t phenomena, char acterized by slow speed of reaction, can only be investigated systematically with any prospect of success if the relationships in the ideal case of actual equilibria are known The degree of deviation from these in each given case could then be judged Well-defined phase relations and their thermal stability are a necessary prerequisite for enlightened material design, allowing intel ligent selection of materials and manipulation of the composition-phase assembly-controlled properties REFERENCES Anderson, D H., Fucinari, C Α., Rahnke, C J., and Rossi, L R (1975a) U.S Energy Res Dev Admin Contract N o E ( l 1-1)2630 Anderson, D H., Fucinari, C Α., Rahnke, C J., and Rossi, L R (1975b) U.S Energy Res Dev Admin Contract N o 68-03-2150 Austin, J B (1952) J Am Ceram Soc., 35, 243 Beall, G H (1975) In "Microstructure of Ceramics." Br Ceram Soc Beall, G H., and Duke, D A (1971) U.S Patent N o 3,600,204 Bowen, M L., and Greig J W (1924) J Am Ceram Soc 7, 238 Buljan, S T and Kleiner, R N (1975) ASME Publ 15-GT-66 Bush, E A and Hummel, F Α., (1959) / Am Ceram Soc 42, 388 Cleveland, J J., Fritsch, C W., and Kleiner, R N., (1977) ASME Publ 77-GT-98 Confer, J O., and McTaggart, G D (1973) U.S Patent N o 3,715,220 Fermor, L L (1924) Q J Geol Soc London 80, - Fisher, G R., Evans, D C , and Geiger, J E (1974) Abstract B-18, Am Cryst Assoc Prog Abstr Ser 2, 2, 214 Fritsch, C W., and Buljan, S T (1976) U.S Patent N o 3,979,216 Fritsch, C W., and Cleveland, J J (1973) Private communication Gilley, F H., and Bush, E A (1959) / Am Ceram Soc 42, 175 VI SILICATES FOR THERMAL SHOCK RESISTANT APPLICATIONS 321 Grossman, D G., and Lanning, J G (1977) / Am Ceram Soc 56, 474 Grossman, D G., and Rittler, H L (1974) U.S Patent N o 3,834,981 Hasselman, D P H (1970) J Am Ceram Soc 49, 1033 Hatch, R A (1943) Am Minerol 28, (9, 10), 471 Hortal, M., Villar, R., Vieira, S., and Moya, J S (1975) J Am Ceram Soc 58, 262 Hummel, F A (1951), / Am Ceram Soc 34, 235 Hummel, F A (1955) Ceram Ind., 65 (6), - Hummel, F A (1960) U.S Patent, Re 24,795 Hummel, F Α., and Reid, H W (1951) J Am Ceram Soc 34, - Iiyama, T (1955) Proc Imp Acad Tokyo 31, 166-168 Iiyama, T (1958) C R Acad Sci 246, - Karkhanavala, M D , and Hummel, F A (1953) J Am Ceram Soc 36, - Kracek, F C (1930) J Phys Chem 34, (Pt II), 2645 Lachman, I M., and Lewis, R M (1975) U.S Patent N o 3,885,977 Lee, J D , and Pentecost, T L (1976) J Am Ceram Soc 59, 183 Levin, Ε M., Robbins, C R., and McMurdie, H F (1969a) "Phase Diagrams for Ceramists," 2nd ed., Fig 449 A m Ceram S o c , Columbus, Ohio Levin, Ε M., Robbins, C R., and McMurdie, H F (1969b) "Phase Diagrams for Ceramists," 2nd ed., Fig 712 A m Ceram S o c , Columbus, Ohio Miyashiro, A (1957) Am J Sci 225, - Miyashiro, Α., and Iiyama, T (1954) Proc Imp Acad Tokyo 30, - Miyashiro, Α., Iiyama, T., Yamasaki, M., and Miyashiro, T (1955) Am J Sci 253, 185-208 Moya, J S., Verduch, A G., and Hortal, M (1974) Trans Br Ceram Soc 73, 177 Osborn, E F., Devries, R C , Gee, Κ H., and Kraner, Η M (1954) Trans AIME 200, 38-39 Osborn, Ε E., and Muan, A (1969) "Phase Diagrams for Ceramists" (edited by Ε M Levin, C R Robbins, and H F McMurdie) A m Ceram S o c , Columbus, Ohio Petticrew, R W (1971) U.S Patent N o 3,625,718 Planchock, J L., Stewart, D R., and Brock, T W (1974) U.S Patent N o 3,841,950 Rankin, G Α., and Merwin, Η E (1918) Am J Sci Ser 4, 45, - Rapp, J E (1973) Bull Am Ceram Soc 52, 499 Roy, R., and Osborn, E F (1949) / Am Chem Soc 71, 2086 Roy, R., Roy, D H., and Osborn, E F (1950) / Am Ceram Soc 33, 152 Schreyer, W., and Schairer, J F (1961) J Petrol 2, - Schreyer, W., and Yoder, H S (1960) Carnegie Inst Washington Yearb 59, - Schulz, H (1974) J Am Ceram Soc 57, 313 Singer, F (1946) Trans Can Ceram Soc 15, Commun N o 124 Smith, G P (1966) U.S Patent N o 3,246,972 Smoke, E J (1969) U.S Army Electron Command Contract D A A B 07-67-C-0232 Smyth, Η T (1955) J Am Ceram Soc 38, 140 Tien, Τ Y., and Hummel, F A (1964) J Am Ceram Soc 47, 582 Tirrell, Μ E., Gibbs, G V., and Shell, H R (1961) U.S Bur Min Bull 594 Tscherry, V., Schulz, H., and Czank, M (1972) Ber Deut Keram Ges 49, 153 Venkatesh, V (1952) Am Min 37, - 8 Venkatesh, V (1954) Am Min 39, 6 - 6 Yoder, H S., Jr (1952) Am J Sci Bowen Vol., - Index A Abukumalite, 198 Aerospace industry, coatings used in, - A g C l - N a C l s y s t e m , 160-161 Alloy chemistry, 2 - A l 20 3- T i s y s t e m , Aluminum, see also A I 20 3- T i system; A l - Z n system Aluminum-avoidance rule, 41 Aluminum chloride, crystalline, 59 Aluminum trichloride, 59 A l - Z n s y s t e m , 153-157 Amorphous silicon monoxide, 51 A n d e r s o n - L i b o w i t z model, 105 A n i o n - e x c e s s o x i d e s , 101-102 Anion substitutions, in apatites, - Anisotropic molecular units, 62 Anti-Schottky disorder, 83 Antistructure disorders, 83 Apatite(s) anion deficient, 231 anion substitutions in, - cation substitutions in, 191-203 crystal chemistry and phase equilibria of, 185-236 crystal growth in, 2 - defined,186-187 gel growth in, 2 - ionic substitutions in, 190-206 low temperature solution equilibrium for, 223-229 melt growth in, - phase equilibria in, - 2 silicate, 200-201 solution growth in, 229 structural description of, 189-190 synthesis of, 188 unit cell parameters of, 214 Apatite crystalline solutions, 204 Apatite s y s t e m s , high-temperature equilib ria in, - 2 Apatite-type c o m p o u n d s , synthetic, 198 Aragonite, under ambient conditions, 57 Aromatic c o m p o u n d s , packing coefficients for, 36 Aromatic ring molecules, 34 A u - N i s y s t e m , 158-159 A u - P t s y s t e m , 157-158 p - A z o x y a n i s o l e , 69 Β Barically stranded phases, 56 B a T i 3- B a H f system, 46 bcc metals, stability of, 22 Beckelite, 199 B e F 2- S i system, Bernal liquids, 65 Bernal model, 57 Binary alloys, order-disorder in, 39 Binary phase diagrams, Binary systems free energy curve for, 130 principles of, Bonding, in nonmetallic elements, 21 Borax-tincalconite reversal, 55 Born model, for ionic crystals, 12 B o w e n ' s reaction series, 63 Britholite, 198 Bromaplaite, 233 323 324 INDEX C C a F 2- T h system, Calcium complete substitutions for, 192 partial substitutions for, 192-196 Calcium aluminum hydroxide, transforma tion to grossularite, 10 Camphor, as plastic crystal, 70 C a O - M g O - P 20 5- H 20 s y s t e m , 221 C a O - P b O - P 20 5- H 20 system, 222 C a O - P 20 + aqueous carbonate and other solutions, 227 C a O - P 20 binary system, 207 C a O - P 20 5- C a F system, 215 C a O P 20 5- C a O B 20 s y s t e m , 222 C a O - P 20 5- C a ( O H ) system, 209, 223 C a O - P - H - C - C a F s y s t e m , 217 C a O - S r O - P 20 5- H 20 s y s t e m , 221 C a O - Z r system, Carnegieite, - Cation substitutions, in apatites, 191-203 C d I 2- Z r S e system, Cellular growth, as nucleated precipitation, 17 Ceria, as densifying additive, - Cerium sialon s y s t e m s , 279 C e - S i - O - N s y s t e m , 279-281 Cesium chloride, packing fractions for, 48 Chemical vapor deposition, 165 Chlorapatite, 197 Cholesteric liquid crystals, - Close packing organic crystals and, 34 in phase prediction, - 3 structures based on, 31 Clustering, Coherent spinodal, - , 153-176 Compositionally stranded phases, 56 Compound formation, miscibility and, - Configurational entropy, for ice, 44 C o O - C a O system, 164 C o O - N i O system, 164-166 Cordierite, 309-311 cavities in, 16 synthetic, 313 thermal expansion of, 311 - 3 Cordierite ceramics, 3 - microcrack formation in, 319 Coulomb's law, Pauling's rules and, 28 Covalent bonds, in molecular packing, 33 Crystal chemistry of apatites, 185-236 phase diagrams and, 1-71 topotaxy and, 53 Crystal growth in apatites, 2 - hydrothermal preparation in, - 3 Crystalline mixed o x i d e s , 162-172 Crystallographic viewpoint, Crystallographic shearing mechanisms, 117-118 Crystals, anion exchange into, - Crystal structures electronic configuration in, 22 prediction of, 18-20 pressure and, 49 relative stability of, 19 Crystal chemistry, rate-determining process and,55 C V D , ^ Chemical vapor deposition D Defect c o m p l e x e s , coherent integration in, 102 Defect conglomerates, 13-14 Defect interactions, in grossly nonstocyiometric o x i d e s , - Defect solid solution, 12-15 Defects, randomly distributed and nonin teracting, - Diamond crystals, intolerance to substitu tion, Dickite, 38 DietzeFs correlation, - Displacement transformations, 39 Disproportionation, in various c o m p o u n d s , 52 Ε Electronic configuration in alloy chemistry, 22 crystal structures and, 22 Ellestadite, 198 Entropy position disorder and, 58 structure of, 2, - thermal versus configurational, - Epitaxy defined, 52 topotaxy and, - 325 INDEX Eucryptite,292 β-Eucryptite solid solution field, - Hydrogen bonds, van der Waals distances and,34 Hydrogen incorporation, in intermetallic c o m p o u n d s , 15 F fee metals near-identity with hep structures, 23 phase diagrams of, 22 Fluorapatite, 197 Flux growth, 3 - Forbidden energy gap, 85 Free energy coherent and incoherent, 138 Gibbs,43,47 Helmholtz, 132 Frenkel disorder, 83 Frenkel model, - , 65 G Gibbsfree energy phase stability and, 43 and stability of solids, 47 Glasses cordierite type, 318 isoviscosity lines for, 66 as noncrystalline solids, - spinodal decomposition in, 172-175 Glass formers, 66 Grossly nonstoichiometric o x i d e s defect interactions in, - thermodynamic models for, 103-111 thermodynamics of, - 2 Grossularite, transformation from calcium aluminum hydroxide, - Growth w i n d o w , in spinodal decomposi tion, 148 Η h e p , see Hexagonal close-packed structures Heat exchanger requirements, in silicate de velopment, 288-291 Helmholtz free energy, for nonuniform sys tem, 132 Hexagonal close-packed structures, 22 High-temperature g a s e s , molecular species in, - Hybrid crystals, microdomains in, 112 Hydrogarnet-grossularite series, Hydrogen metallic, 52 phase transformation in, 52 I Ice, configurational entropy for, 44 Immiscible liquids, - Imperfections, ionization of, 86, see also de fect entries Intermetallic c o m p o u n d s hydrogen incorporation in, 15 stability ranges for, 22 Interstitial sites, steel as example of, 12 Ionic o x i d e s , predominant defects in, 91 Ionic structures, Pauling's rules for, - Iron-carbon system, in steel making, 12 Isomorphs, defined, 37 Isoviscosity lines, for glasses, 66 J Jahn-Teller phase transition, 41 Κ Kalsilite, 56 Kaolin minerals, polymorphs in, 37 K C l - N a C l s y s t e m , 161-162 Kernite, temperature-solubility curve for, 55 Kinetic distribution function, 135 Kinetics, metastable phases and, - K M g F 5- S r T i system, K o c h defect cluster, 14 Kotoite, close packing in, 32 L L A S , see Lithium alumina silicate Lattice energy, phase prediction and, - Lead titanate, morophotropic phase bound aries a n d , Lead zirconate titanate, in sonar and trans ducer applications, 45 Lessingite, 199 L i F - M g O system, L i - M o system, Liquid(s) Bernal model of, 57 melting and, - Frenkel model of, 57 Stewart model of, 58 INDEX 326 Liquid crystals, - Liquid immiscibility, in glass forming sys tem, 67 Liquidlike solids, 68 Lithium-aluminum-silicate matrices, mod ifications of, 308 Lithium-aluminum-silicates s y s t e m low expansion bodies in, 306 low thermal expansion type, - phase diagrams for, - as regenerator materials, 289 thermal expansion of c o m p o u n d s in phase diagrams of, - Lithium sialons, 272 Long-chain hydrocarbons, melting and boil ing points of, 63 Μ Magneli phases, 14, 80, 163 Magnesium, see also M g A I 20 - A l 20 sys tem Magnesium aluminum silicates, - Magnesium sialons, 6 - Magnetoplumbite, close packing of, 32 Mass action, law of, 86 Melting point, bending and, - Mesomorphic states, 68 Metallic hydrogen, stored energy in, 52 Metallic oxides nonstoichiometric range for, 90 predominant defects in, - Metallic s y s t e m s , in spinodal d e c o m p o s i tion, 153-159 Metal-sialon s y s t e m s , representation of, 261-265 Metal vacancies, neutral, 92 Metastable phases kinetics and, - stranded phases and stuffed derivations in, - topotaxy and, - 5 nucleation and growth within, 129 M g A l 20 4- A l 20 s y s t e m , 4, 166-168 M g F 2- T i s y s t e m , M g O - B e O additions, - M g O - C a O s y s t e m , 170-171 M g O - C o O s y s t e m , 171 M g O - M g A l 20 system, 168 M g O - T i system, M g - S i - A l - O - N systems, 266-273 Microcline, 42 Microdomains in hybrid crystals, 112 stability in, 113 thermodynamics of, 111-116 Miscibility, compound formation and, - Miscibility limits, phase diagrams and, 10-12 Model structures, 6, - , 65 Molecular shape, packing efficiency and, 26 Moon rocks, crystalline structure of, 51 Morphotropic phase boundaries, - Ν Nacrite, 38 Nematic liquid crystals, 69 N i O - C a O s y s t e m , 11, 14 N i O - M g O s y s t e m , 11 Nitrogen ceramics cerium-containing, 280-281 silicates and, - Nitrogen glasses, - Noncrystalline solids versus crystalline and amorphic solids, 64 glasses as, - melting of, - melting and boiling points of, - Nonmetallic e l e m e n t s , bonding in, 21 Nonstoichiometric binary o x i d e s classification of, - defect structures and thermodynamic theories of, - 2 with narrow composition ranges, - structure of, - 2 thermodynamics of, - 2 Nonstoichiometric phases intermediate line phases in, 80 thermodynamic considerations in, - Nonstoichiometry structural coherence in, 14 in transition-metal o x i d e s , 92 N - Y A M , yttrium aluminate and, 274 Ο Organic crystals, close-packing c o n c e p t s and,34 Organizational randomization, 59 Oxide phase diagrams, valence and, Oxyapatites, miscellaneous, 2 - 2 Oxygen-deficient o x i d e s , defects in, 100 INDEX 327 ρ Packing coefficients, for aromatic com pounds, 36 Packing density, molecular volume and, 35 Packing efficiency, 35 molecular shape and, 36 Parsimony rule, 29 Pauling-Ahrens radii, packing percentages and,32 Pauling's half-hydrogen mode, 44 Pauling's rules application of, - in phase prediction, - topaz and, - P b Z r 3- P b T i system, 46 Perovskite family, phase transformation in, 40 Petalite, 292 Phase diagrams binary,3 crystal chemistry and, 1-71 in development of silicates for thermal shock resistant applications, - intermediate phases in, in low thermal expansion lithiumaluminum-silicate ceramic develop ment, - metastable phases and kinetics in, - miscibility limits and, 10-12 model structures and, oxide, polymorphism and, 37-51 sialons and, - in silicate development, - solid solutions and, - structure types and, thermal expansion of c o m p o u n d s in, 297-302 Phase equilibrium, - 2 for apatite family, 186 Phase prediction, 18-37 close packing and, - 3 lattice energy and, - and molecular packing in organic crystals, 33-37 packing density and, 35 Pauling's rules in, - Ramberg's rules in, - Phases basically stranded, 56 compositionally stranded, 56 Phase separation, of spinodal m o d e , 129 Phase stability, Gibbs free energy and, 43-45 Phase transformation in hydrogen, 52 polymorphism and, - speed of, 41 temperature and, Phase transitions, Λ e e also Phase transforma tion origins of, 41 pressure and, 48 sluggish, 56 Phosphorus complete substitution for, 2 - partial substitution for, 2 - polygraphs of, 51 substitutions for, 196-203 Plagioclase feldspars, Planar disk, vacancies in, 117 Plastic crystals, 68-71 Point defects, creation of, 84 Polymorphism, 37-51 entropy and structure in, - morphotropic phase boundaries and, 45 phase transformation and, - , 47-51 Polymorphs Coulomb energy and, 38 defined,37 of phosphorus, 51 polytypes and, 39 Polytypes, defined, 39 Positional randomization, 58 Precipitation reactions, in solids, 16-17 Pressure crystal structure and, 49 in phase transitions, 49 PZT, see Lead zirconate titanate Q Quartz crystals, intolerance of to substitu tion, Quartz-tridymite transition, 41 R Ramberg's rules, - Randomization, - Rare-earth vanadates, 41 328 INDEX Rate-determining process, crystal clustering and,55 R b B F 4- B a S system, Reconstructive transformations, 39 Rochelle salt, low-temperature transistion in,41 Rock salt, packing fractions for, 48 Rosenhahnite, silica tetrahedra in, 54 Rosenhahnite-wollastonite transformation, 54 Rutile, thermodynamic and structural be havior i n , S Sandine, 50 SAXS,.??? Small angle x-ray scattering Schottky disorder, 83 Shear and block structures, ther modynamics of, 116-122 Shear planes, formation and ordering of, 121 S i - A l - O - N phase diagrams, 258-261 S i - A l - O - N system, - 5 phases of, 5 - Sialons early work in, 246-255 single-phase, 270-271 yttrium, - 7 Silicate apatites, unit cell dimensions of, 200-201 Silicate oxyapatites, 201 Silicates nitrogen ceramics and, - pressure transformations of, 50 Silicon dioxide, polymorphs of, - Silicon monoxide, anamorphous, 51 Silicon nitride, - alumina and, - hot-pressed, - mixed oxides a n d , - S i 3N 4- A l 20 3A l N system, 249-251 Site exclusion principle, 107 Small angle x-ray scattering, in spinodal de composition, - , , 172-174 Smectic liquid crystals, 69 Solidlike liquids, 68 Solids noncrystalline, 57-71 precipitation reactions in, 16-17 Solid solutions, - ''perfect," substitutional, - Spinel crystals, precipitation strengthening of, 16 Spinodal, coherent, 137-141, 153-176 Spinodal decomposition, 17 alkali halide s y s t e m s and, 160-162 coherent spinodal in, 153-176 continuous process in, 137 crystalline mixed oxides in, 162-172 defined, 128-129 diffusion coefficient in, 136 experimental studies in, 141-152 free e n e r g y - c o m p o s i t i o n - t e m p e r a t u r e re lations in, 130-137 in geologic s y s t e m s , 175-176 in glasses, 172-175 ideal versus reality in, 141-143 kinetic aspects of, 134 metallic systems in, 153-159 morphology in, 143-147 phase diagram representation and occur rence in 127-128 small angle x-ray scattering in, 147-150 thermodynamics of, 130-141 transmission electron micrograph in, 151 vis-a-vis nucleation and growth, 129-130, 144 X-ray diffraction and other techniques in, 150-152 Spinodal mechanism, nucleation versus growth in, 129-130, 144 Spodumene, 292 β-Spodumene solid solution field, 295 Steel, phases in hardness and ductility of, 12 Stewart glasses, 65 Stewart model, 58 Stoichiometric o x i d e s , thermodynamics of defect formation in, - Stranded phases, 56 Strontium, in aragonite, 57 Structural coherence, in nonstoichiometry, 15 Structure-field maps, - Substitutional solid solutions, - Τ T E M , see Transmission electron micro graph Ternary system, principles of, Thermal entropy, versus configurational, 43-44 329 INDEX Thermal shock resistant silicates, - silicate strength and, 291 in turbine heat exchanger materials, 290 Thermal stranding, 56 Thermal transformations, energy change and,40 Thermodynamic models, for grossly nonstoichiometric o x i d e s , 103-111 Thermodynamics of defect formation in stoichiometric oxides, 82-94 of grossly nonstoichiometric o x i d e s , 94-122 of microdomains, 111-116 of nonstoichiometric phases, - of shear and block structures, 116-122 T h o r n b e r - B e v a n defect c o m p l e x , 110 Tincalconite-borax reversibility, 55 Titanium oxide, defects in, 13 Titanium tetrachloride, 60 Tooth enamel, acids and, Topaz, Pauling's rules and, 29 Topotaxy, 52-57 crystal chemistry and, 53 defined, 52 epitaxy and, 52 morphology and, 53 Transition-metal c o m p o u n d s , crystallization of, 24 Transition-metal monoxides composition ranges and defect types in, 91 nonstoichiometric range for, 93 Transition-metal oxides anion-deficient, 116-117 nonstoichiometry in, 92 Transmission electron micrograph, 151, 163, 165,168, 173-174 Trapped g a s e s , - Tridymite, 56 Turbine heat exchanger materials, thermal shock resistance in, 289 U Unstable region, spinodal decomposition within, 129 Urania, hyperstoichiometric, 106 V Vacancies, in planar disk, 117-119 Valence bond theory, - 2 Vanadates, crystallography of, 41 Van der Waals forces, - , 33, - V o l m e r - W e b e r - B e c k e r - D o r i n g formula tions, 129 W Wollastonite, silicate chains in, 54 Wustite disproportionation in, 52 eutectoid decomposition in, 17 X X-ray diffraction, in spinodal decomposi tion, \50-\52, see also Small-angle x-ray scattering Y Y A M , see Yttrium aluminate Y2O3-S13N4 ceramics, oxidation resistance of, 275 Y _ S i - A l - - N system, 277-279 Y _ S i - - N s y s t e m , 273 Yttrium aluminate, 274 Ζ Zincblende, packing fractions for, 48 Zinc orthosilicate, Zirconia additions, densification with, 281 — 282 Zirconium sialons, - .. .PHASE DIAGRAMS Materials Science and Technology Edited by A L L E N M ALPER Director Chemical of Research GTE Sylvania, Towanda, and and Metallurgical Engineering... Enthropy and Structure C Morphotropic Phase Boundaries D Phase Transformations under Pressure V Metastable Phases and Kinetics A Topotaxy B Stranded Phases and Stuffed Derivatives VI Liquids and. .. The Use of Phase Diagrams i n Electronic Materials and Glass Technology I II III T h e U s e of P h a s e Diagrams in Crystal G r o w t h J W Nielsen and R R Monchamp T h e U s e of the Phase Diagram