Thermo-Mechanical and Thermo-Chemical Processes

Microstructural features like grain size, phase fraction and size distribution can be tailored by understanding and optimizing thermo-mechanical and thermo-chemical processes i.e. coupling the heat treatment either by introduction of mechanical energy into solids or by altering the chemistry of solids. Accordingly, several Thermo-Mechanical and Thermo-Chemical processes/treatments have been developed by the researchers. This course is designed to provide the fundamental science behind these processes so that optimal utilization of these processes is possible. Course will cover the utilization of flow stress data from hot deformation experiments to develop constitutive equations and processing maps, the interrelationship between microstructure and deformation features with the thermo-mechanical deformation processes. Important thermo-chemical processes such as nitriding, carburizing, carbonitriding, nitrocarburizing and boriding will be covered.INTENDED AUDIENCE:Final year B.Tech., M.Tech. and PhD scholars in Metallurgical Engineering or Materials Engineering. Practicing engineers in steel and aluminum industries.PREREQUISITES:Mechanical Metallurgy, Physical Metallurgy, Basic Thermodynamics.INDUSTRY SUPPORT:SAIL, TATA steel, Essar Steel, BHEL, JSW steel, Hindalco, Tata Motors, Larsen & Toubro.

Week 1:Introduction, Hot deformation processes I, Hot deformation processes II, Flow curves as a function of strain rate and temperature, Stress, strain, strain rate sensitivity.
Week 2:Microstructural evolution, Recovery, Recrystallization, Dynamic recrystallization, discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), geometric dynamic recrystallization (GDRX).
Week 3:Texture, Deformation texture (BCC), Deformation texture (FCC), Recrystallization texture (BCC), Recrystallization texture (FCC).
Week 4:Constitutive analysis, Low strain rate , Medium strain rate, High strain rate, case study
Week 5:Deformation maps, Processing maps, Different models, Interpretation, Processing maps microstructure correlation, case study.
Week 6:SPD based thermo-mechanical processes, Friction stir Processing, Equal Channel Angular Processing, High pressure torsion, case study.
Week 7:Introduction to Thermo-chemical surface treatments, Thermodynamics of gas/solid interaction.
Week 8:Phase transformations and consequent surface property enhancement during nitriding of iron based alloys.