JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD

Prerequisite

Physical Metallurgy

Course Objectives

The main objectives are to provide students with basic understanding of phase

transformation by heat treating and stress-induced hardening, linear and nonlinear elastic behavior, deformation under multiaxial loading, plastic deformation and yield criteria, dislocation plasticity and strengthening mechanisms, creep, stress concentration effects, brittle versus ductile fracture, fracture mechanisms at different scales, fatigue, contact deformation, and wear.

Course outcomes: After completing this course, the student should be able to understand the different modes of failures like fracture, fatigue and creep of ductile and brittle materials

UNIT - I

Fracture: Introduction, Types of Fracture in Metals, Griffith Theory of Brittle Fracture, Fracture of Single Crystals, Ductile Fracture, Concept of the Fracture Curve. Fracture Mechanics: Strain Energy Release rate, Fracture Toughness and Design, Crack Opening Displacement, J-Integral, R Curve,

UNIT - II

Theory of Elasticity and Plasticity: Elasticity Theory: The State of Stress and strain, elastic stress-strain relation, anisotropy, elastic behaviour of metals, ceramics and polymers. Plasticity: Hydrostatic and Deviatoric stress, Octahedral stress, yield criteria and yield surface, texture and distortion of yield surface, true stress and true strain, flow rules, strain hardening, Ramberg Osgood equation, stress -strain relation in plasticity, plastic deformation of metals and polymers

UNIT - III

Fatigue-I: Introduction, Stress Cycles, S-N Curve, Effect of Mean Stress on Fatigue, Cyclic Stress strain curve, Low Cycle Fatigue, Strain Life Equation, Structural Features of Fatigue, Fatigue Crack Propagation, Effect of Metallurgical Variables on Fatigue.

UNIT - IV

Fatigue-II: Effect of stress concentration on Fatigue, Size Effect, Surface effects on Fatigue, Fatigue under Combined stresses, Design for Fatigue, Machine Design approach-Infinite life design, Local strain approach, Corrosion Fatigue, Effect of Temperature on fatigue.

UNIT - V

Creep deformation: The evolution of creep damage, primary, secondary and tertiary creep, Micro mechanisms of creep in materials and the role of diffusion, Ashby creep deformation maps. Stress dependence of creep – power law dependence. Comparison of creep performance under different conditions – extrapolation and the use of Larson-Miller parameters, Creep-fatigue interactions, Examples.

TEXT BOOKS:

• 1. Mechanical Metallurgy by G. E. Dieter, McGraw Hill, (1988)
• 2. Thin Film Materials L.B. Freund and S. Suresh, Cambridge University Press (2003). R19 M.Tech. CAD/CAM

REFERENCE BOOKS:

• 1. Fracture Mechanics Fundamentals and Applications by T.L. Anderson, 2nd Ed. CRC press, (1995)
• 2. Fracture of Brittle Solids by B. Lawn, Cambridge Solid State Science Series 2nd ed 1993.
• 3. Fundamentals of Fracture Mechanics by J.F. Knott, Butter worths (1973)
• 4. Worked examples in Fracture Mechanics by J.F. Knott, P Withey, Institute of Materials.
• 5. Fracture Mechanics by H.L. Ewald and R.J. H. Wanhill, Edward Arnold, (1984).
• 6. Fatigue of Materials by S. Suresh, Cambridge University Press, (1998)
• 7. Inelastic Deformation of Metals by D.C. Stouffer and L.T. Dame, Wiley (1996)
• 8. The Physics of Creep by F.R.N. Nabarro, H.L. de Villiers, Taylor and Francis, (1995) R19 M.Tech. CAD/CAM M. TECH. I Year I Sem. (CAD/CAM)