Course Details
Subject {L-T-P / C} : CR2104 : Process Ceramics { 3-0-0 / 3}
Subject Nature : Theory
Coordinator : Prof. Santanu Bhattacharyya
Syllabus
Module 1 Introduction to the course
Introduction and importance of studying Process Ceramics. Intrinsic and extrinsic properties of ceramics and its influence of application. Importance of different processing steps and powder characteristics on the evolution of different microstructure. Brief overview of some commercially utilized some non-conventional industrial processing routes for advanced ceramics fabrication- DIMOX, Reaction Bonding, Sol-Gel, Melt Quenching 4Contact Hours
Module 2 Powder Synthesis by solid state and liquid precursor routes
Mechanochemical synthesis, Decomposition Routes- mechanism, kinetics, Compound Formation- spinel formation and kinetics, Precipitation route- principle of homogneous and heterogeneous precipitation, powders with uniform particle size, coated powders, powder synthesis by liquid evaporation routes- spray drying, spray pyrolysis, freeze drying. Hydrothermal synthesis. Gel route- Pechini process, combustion synthesis 7Contact Hours
Module 3 Particle size, porosity and pore size
A brief discussion on particle size distribution models. Particle size determination by sedimentation method- layer technique and homogeneous technique. Coulter counter and laser scattering technique. Specific surface area measurement by BET adsorption, pore size determination by gas adsorption method andmercury porosimetry method 6Contact Hours
Module 4 Packing of powders and consistency states
Ceramic fabrication and particle packing. Random packing of powders. One and two component particle packing. McGeary packing theory- binary and ternary packing. Furnas packing diagram, packing of continuous particle size- Andreasen model, Dinger-Funk model
Different consistency states of powder- bulky, granular, plastic, paste and slurry. The significance of each consistency states on ceramic processing and fabrication. Effect of particle-particle interaction, additives, binder, deflocculant on changesin consistency state7 Contact Hours
Module 5 Ceramic Fabrication Process
Ceramic forming and process reliability.Correlating consistency states and ceramic fabrication process. Shape forming of dry and semi-dry powder mixture. Uniaxial dry pressing and compaction stages. Additives and binders. Effect of RH on compaction and pore removal. Pressure gradient in uniaxial pressing. Pressing defectsin uniaxial pressing. Isostatic pressing – dry and wet bag isostatic pressing. Problems in isostatic pressing 8 Contact Hours
Module 6Particle charging, colloidal stability and rheology of ceramic slurries
Origin of particle charge in ceramic oxides, Stern double layer and diffuse double layer theory, flocculation and deflocculation, iso-electric point, zeta potential and significance of zeta potential in colloidal stability. Non-newtonian behaviour of ceramic slurries. Einstein equation, Doherty-Kreiger equation, solid loading and no-flow condition. Effect of particle size distribution on flow behaviour of concentrated ceramic slurries. 8 contact hours
Module 7 Filtration of slurry and slip casting
Filtration mechanism through a porous filter bed. Karmen- Cozeny equation. Filtration rate equation. Slip parameters affecting filtration. Relation between filtration and slip casting. Slip casting mechanism. Slip parameters affecting slip casting of slurries. Slip casting mechanism of triaxial porcelain and that of a deflocculated alumina slurry. Mould properties and slip casting rate. Good slip and poor slip properties – particle size distribution and slip casting behaviour. Tape casting- mechanism, slip preparation, casting specialities.8Contact Hours
Course Objectives
- To provide an in-depth understanding of the science of Ceramic Processing and Fabrication
- To correlate material properties with powder and particle characteristics and to design appropriate processing method for ceramic fabrication for a specific use.
- To correlate microstructure and the processing related defects leading to defects, and rejection of shaped body.
- To utilize the above knowledge to design, develop and upgrade products for different commercial and strategic applications.
Course Outcomes
CO1: To be well versed about different aspects of ceramic processing routes and to use them to fabricate ceramic products for different applications. <br />CO2: To understand the importance of ceramic powder science and to correlate the powder characteristics to the developed ceramic product. <br />CO3: To be able to decide the optimum processing for a ceramic product on the basis of available inputs, raw materials, and existing processing capabilities. The developed technology should be eco-friendly also <br />CO4: To be able to do analysis of defective and rejected components to ascertain the root cause of defective products. <br />CO5: To modify the existing process on the basis of customer feedback, analysis, survey and suggest an upgraded process/technology for improved product quality.
Essential Reading
- J S Reed, Introduction to the Fundamentals of Ceramic Processing, 2nd Ed., John Wiley & Sons. 1995.
- M N Rahaman, Ceramic Processing, CRC Press 2006
Supplementary Reading
- D W Richerson, Modern Ceramic Engineering: Properties, Processing, and Use in Design, 3rd Edition, CRC Press, 2005
- D A Brosan and J A Robinson, Introduction to Drying of Ceramics, Wiley-American Ceramic Society
Journal and Conferences
- R K McGeary Mechanical Packing of Spherical Particles J Am Ceram Soc 1961