JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Overview

Course objectives: To introduce the student to key concepts in Phase transformations and enable an understanding of the steps involved in several important phase transformations.

Course outcomes: After completing this course, the student should be able to:

• Classify phase transformations
• Indicate important steps in different types of phase transformations
• Explain phase transformations from the perspective of thermodynamics and kinetics
• Describe a few well known and studied phase transformations

UNIT - I

Definition and types of Phase transformations, Diffusion: Fick's laws of diffusion, solution of Fick's second law and its applications, atomic model of diffusion and role of crystal defects, temperature dependence of diffusion coefficient.

UNIT - II

Kirkendall effect. Diffusional transformation in solids and diffusionless transformation in solids. Nucleation and growth, energy considerations; homogeneous nucleation, heterogeneous nucleation, growth kinetics, overall transformation rates.

UNIT - III

Crystal interfaces and microstructure. Microstructure evolution, including recrystallization and grain growth. Precipitation from solid solution: Homogeneous and hetrogeneous nucleation of precipitates, the aging curve, mechanisms of age hardening, examples from Al-Cu and other alloy systems.

UNIT - IV

Martensitic Transformations: General characteristics of martensitic reactions, similarity to deformation twinning, bain distortion, crystallography and kinetics of martensitic transformations, examples from ferrous and non-ferrous alloy systems.

UNIT - V

Order-disorder Transformation Examples of ordered structures, long and short range order, detection of super lattices, influence of ordering on properties. Spinodal decomposition.

TEXT Books:

• 1. Solid State Phase Transformations, V. Raghavan, Prentice Hall India Learning Private Limited, 1987.
• 2. Phase Transformations in Metals and Alloys, David A. Porter and Kenneth E. Easterling, Third Edition, CRC Press, 2017

REFERENCE Books:

• 1. Physical Metallurgy Principles, Reza Abbaschian, Lara Abbaschian, and Robert E. Reed- Hill, Cengage, 2013
• 2. Mechanisms of Diffusional Phase Transformations in Metals and Alloys,Hubert I. Aaronson, Masato Enomoto, and Jong K. Lee, CRC Press, 2016. R18 B.TECH MME