Course Details
Subject {L-T-P / C} : CR2106 : High temperature processes in ceramics { 3-0-0 / 3}
Subject Nature : Theory
Coordinator : Prof. Shantanu Kumar Behera
Syllabus
Module 1: Fundamentals of high temperature processes in ceramic fabrication, processes, and properties, Defects in crystalline solids, Defect chemistry, Kroger-Vink notations, Defect equilibrium, Diffusion and driving forces, Fick’s laws, Diffusion kinetics and activation energy, diffusion types and coefficients, Chemical potential, Chemical potential of atoms and vacancies, Chemical potential of curved surfaces, Diffusional flux equation.
Module 2: Basics of solid-state sintering, Sintering mechanisms, 3-particles model, Herring’s scaling law, Application of scaling law in various sintering mechanism, Sintering stages and microstructural features, Geometrical model for initial sintering stage, Generalized expression, Intermediate sintering stage: geometrical model and constitutive equation, Final sintering stage.
Module 3: High temperature processes under externally applied load, Creep, Stages of creep, Constitutive model, Nabarro-Herring creep, Coble creep, Dislocation creep, Hot pressing mechanisms.
Module 5: Liquid phase sintering: Basic features, Thermodynamic and kinetic factors, LPS additives, Examples, Dihedral angle, Wetting, penetration of grain boundaries by liquid phase, Capillary forces, Densification processes, Microstructural features, Application of phase diagram in LPS.
Module 6: Grain growth: Basics of grain growth and coarsening, Ostwald ripening, Normal and abnormal grain growth, Boundary mobility, Burke-Turnbull model, Solute drag theory (Cahn’s model), Parabolic kinetics, Cubic kinetics, Adsorbate drag, Particle inhibited grain growth and Zener model.
Module 7: Microstructure control: Thermodynamics of pore stability, pore mobility, Kinetics of pore-boundary interaction, Grain growth in porous systems, Brook model, Yan-Cannon-Choudhary model, Harmer model.
Module 8: Special techniques: Use of dopants for the control of sintering/creep, Fast firing method, Two-step sintering method, Sintering of thin films.
Course Objectives
- To provide an in-depth understanding of the basic atomistic phenomena that lead to high temperature processes of ceramics in particular and solids in generals.
- To familiarize students with various types of sintering mechanisms and their applicability in different types of materials fabricated through powder metallurgy route.
- To provide basic ideas of microstructure control during high temperature fabrication and service environment in ceramic materials.
- To provide fundamental aspects of grain growth in dense materials and their control in ceramics and composites.
Course Outcomes
CO1: Ability to apply basic physico-chemical principles to understand high temperature processes in materials in general, and ceramics in particular. <br />CO2: Ability to formulate processing methods for the sintering of single and multi-component ceramic materials. <br />CO3: Ability to comprehend materials microstructures and apply the knowledge in the problem solving of materials fabrication and performance in ceramic industries. <br />CO4: Ability to design microstructures for coarsening-resistant and creep-resistant alloys and composites.
Essential Reading
- Mohamed N. Rahaman, Ceramic Processing and Sintering, Taylor and Francis
- Suk-Joong L. Kang, Sintering: Densification, Grain Growth and Microstructure, Butterworth-Heinmann
Supplementary Reading
- Michel Barsoum, Fundamentals of Ceramics, CRC Press
- W D Kingery, Introduction to Ceramics, John Wiley