Mullite is the most important crystalline phase in fired products belonging to the Al2O3SiO2 mullite system, such as whiteware articles used in daily life (e.g., low- and high-temperature hard porcelain, sanitaryware, and structural clay products). Mullite has attracted increasing interest due to its excellent high-temperature strength and creep resistance, good chemical and thermal stability, low thermal expansion coefficient, and good dielectric properties. Mullitization has been a subject of extensive and controversial investigations. This book comprehensively covers the synthesis and six types of phase transformation of mullite. Part I reviews previous research on the synthesis of mullite gels, advantages and disadvantages of different chemical routes of synthesis, and phase transformation processes. Part II discusses the nature and characterization of spinel and mullite phases and different mechanisms of mullite formation, as conjectured by various researchers. Part III deals with the critical analysis of the spinel and mullite phases and evolution of mullite formation routes. Every chapter is accompanied by detailed diagrams and a comprehensive list of references.
1. Introduction Part 1: Review
2. Mullite Precursors Synthesized by the
Monophasic Gelation Method
3. Mullite Precursors Synthesized by the
Coprecipitation Method
4. Mullite Precursors Synthesized by the Colloidal
Gelation Method
5. Mullite Precursors Synthesized by Codecomposition
Processes
6. Mullite Precursors Synthesized from Other Miscellaneous
Sources/by Other Processes
7. Phase Evolution Sequences of Mullite Precursors
Synthesized by Different Methods Based on Components Used and Processing
Variables
8. Phase Evolution Studies of Various Mullite Gels/ Precursors by
IR and Raman Spectral Techniques
9. Phase Evolution Studies of Various
Mullite Precursors/Gels by MAS-NMR
10. Chemistry of Mullite Formation through
the Sol-Gel Process
11. Homogeneity of Al2O3-SiO2 Gels/Precursors
12.
Comparison of Thermal Transformation Processes of Six Mullite Precursors Part
2: Identification: Characterization of Four Phases of Gel-to-Mullite
Transformation Series
13. Nature and Its Characterization of the
Noncrystalline Al2O3-SiO2 Mullite Precursor Phase
14. Final Dehydroxylation
of Noncrystalline Al2O3-SiO2 Mullite Precursors
15. Spinel Phase: A Concise
Review
16. Mullite Phase: A Concise Review
17. Nature of Residual
Noncrystalline Aluminosilicate Phases Associated with Mullite Formation Part
3: Critical Analysis
18. Critical Analysis and Characterization of Spinel
Phase
19. Critical Analysis and Characterization of Mullite Phase
20.
Emergence of Only Three Routes of Phase Transformation Sequences of Mullite
Precursors and Critical Analysis of Intermediates
21. Critical Analysis of
Classification Scheme of Mullite Gels
Akshoy Kumar Chakraborty is a retired research scientist with more than 40 years of experience in the clay/mullite research field of ceramics. He obtained his BTech in Chemical Engineering (1969), MTech in Glass and Ceramics (1970), and PhD (Sc; 1976) from Calcutta University, India. In collaboration with the National Physical Laboratory, New Delhi, India, he worked on the characterization of a certified silicon powder for X-ray diffraction and with Dr. K.J.D. Mackenzie (Gracefield Research Centre, New Zealand) on solid-state nuclear magnetic resonance studies on leached and heat-treated kaolinites. Dr. Chakraborty has received the International Plato Award for Educational Achievement by the International Biographic Centre, Cambridge, UK, and the Marquis Award. He has authored a book, Phase Transformation of Kaolinite Patents, and co-authored 45 articles and holds a few patents. He is a life member of the Indian Ceramic Society, the Indian Thermal Analysis Society, and the Indian Institute of Ceramics and a reviewer for the American Ceramic Society and Material Science.
