Material Technology - Dec 2016

Mechanical Engineering (Semester 4)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks.

Write a short note any four Q1.(a,b,c,d,e)

1(a) Rotating beam fatigue testing machine(5 marks) 1(b) Effect of alloying elements on phase transformation(5 marks) 1(c) Strain hardening(5 marks) 1(d) Subzero treatment(5 marks) 1(e) Nano Materials(5 marks) 2(a) Derive an expression for critical resolved shear stress. Explain "slip Mechanism" and " twinning mechanism" of plastic deformation(8 marks) 2(b) Defien creep. Explain stages of creep.(6 marks) 2(c) Write short note on Transformed Lediburite.(6 marks) 3(a) Derive an expression for Griffith theory of brittle fracture. Also state Orowan's modifiaction.(8 marks) 3(b) Draw Fe-Fe3C Diagram and explain cooling of 1.0% C alloy in Fe-Fe3C diagram.(12 marks) 4(a) Draw and explain construction of Time Temperature Transformation (TTT) diagrams of 0.8% carbon alloy.(10 marks) 4(b) What is case hardening? Discuss the process of Nitriding and Cyaniding in detail.(10 marks) 5(a) What is recrystallization annealing? Discuss the various stages of recrystallization annealing. What are factor affecting it?(8 marks) 5(b) What are stainless steels? Classify stainless steels. Discuss and mention their applications.(6 marks) 5(c) What are Nano Composites? Give applications of Nano Composites.(6 marks)

Write a short note any four Q6.(a,b,c,d,e)

6(a) Chromising(5 marks) 6(b) Bergervector(5 marks) 6(c) Retained austenite(5 marks) 6(d) Solid solution(5 marks) 6(e) Frank reed source(5 marks)