Mullite is the most important crystalline phase in fired products belonging to the Al2O3–SiO2 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. Mullite synthesis has not been elaborately described in previous books. This book comprehensively covers the synthesis and six types of phase transformation of mullite. Part 1 reviews previous research on synthesis of mullite gels, advantages and disadvantages of different chemical routes of synthesis, and phase transformation processes. Part 2 discusses the nature and characterization of spinel and mullite phases and different mechanisms of mullite formation, as conjectured by various researchers. Part 3 deals with critical analysis of the spinel and mullite phases and evolution of mullite formation routes.
Table of Contents
Part 1: Review 1. Introduction 2. Mullite Formation by Various Chemical Methods and Phase Evolution Behavior Studied by DTA and XRD 3. Concise Review on Mullite Gel/Precursor–Mullite Reaction Sequences Based on Components Used and Processing Variables Chosen during Synthesis 4. Studies on Mullite Gel/Precursor–Mullite Reaction Sequences Based on IR and Raman Spectral Techniques 5. Studies on Mullite Gel/Precursor–Mullite Reaction Sequences Based on the MASNMR Technique 6. Chemistry of Mullite Formation through the Sol-Gel Process 7. Homogeneity of Al2O3–SiO2 Gels/Precursors 8. Comparison of Mullite Gel/Precursor–Mullite Reaction Sequences of 6-Mullite Precursors Part 2: Nature and Characterization 9. Nature of Noncrystalline Al2O3–SiO2 Mullite Precursor Phase and Its Characterization 10. Chemistry of Mullite Formation through the Sol-Gel Process 11. Spinel Phase. A Concise Review of Its Formation and Characterization by QXRD, TEM/EDS, Lattice Constant Studies, and Alkali Leaching Studies, as Reported by Earlier Authors 12. Mullite Phase. A Concise Review of Its Formation and Characterization by QXRD, Lattice Constant Studies, and Critical Analysis by Earlier Authors 13. Nature of Residual Noncrystalline Aluminosilicate Phase Associated with Weakly Crystalline Mullite Formation Part 3: Critical Analysis 14. Critical Analysis and Characterization of the Spinel Phase 15. Critical Analysis and Characterization of the Mullite Phase 16. Emergence of Only Three Routes of Phase Transformation Sequences of Mullite Precursors and Critical Analysis of Intermediates 17. 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. In collaboration with the National Physical Laboratory, New Delhi, India, he worked on 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.