Code: 12D87108

M.Tech I Semester Supplementary Examinations September/October 2015 MATERIAL TECHNOLOGY

(Common to AMS & PE) (For students admitted in 2012, 2013 & 2014 only)

Time: 3 hours Max. Marks: 60 Answer any FIVE questions

All questions carry equal marks *****

1 (a) What is precipitation hardening? Describe the precipitation hardening mechanisms with respect to Al-Cu alloys.

(b) Derive expression for critical resolved shear stress for slip. 2 (a) Explain in detail the fiber strengthening mechanisms. (b) Write short notes on deformation of non-crystalline materials. 3 (a) What is a brittle fracture? Explain Griffith theory for brittle fracture. (b) Give three reasons why the extrapolation of creep data obtained, over a short period can

be dangerous over long periods. 4 (a) Explain the procedure of failure analysis for non-metallic materials. (b) State Paris law. Give an expression for generalized Paris law for fatigue crack growth. 5 Explain with case studies in material selection with relevance to the following applications: (a) Marine. (b) Automobile. (c) Nuclear. (d) Aerospace. 6 Give manufacturing process, chemical composition, properties and applications of the

following steels: (a) Dual phase steels. (b) Maraging steels. (c) HSLA. 7 (a) What are shape memory alloys? Discuss SMA with respect to phase transformation and

methods to study the SMA effect. (b) Give reasons for the development of metal-matrix composites. Name some possible

applications. 8 (a) Write the properties and applications of the following polymers and discuss any one

fabrication methods of polymers. (i) PVC. (ii) PEEK. (iii) PTFE.

(b) What additives are used in plastics? Why?

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