Material Technology - May 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 note on any four

1(a) Thermal fatigue of metal(5 marks) 1(b) Andrade's analysis of classical creep curve.(5 marks) 1(c) Effect of Alloy on Eutectiod temperature and composition.(5 marks) 1(d) Critical resolved shear stress.(5 marks) 1(e) Dislocation Interaction(5 marks) 2(a) What do you mean by Nano-materials? Explain their properties and practical applications.(10 marks) 2(b) What is Fatigue? Explain fatigue testing in detail.(10 marks) 3(a) Draw Fe-Fe₃C Diagram and Explain cooling of 0.9% C alloy in the Fe-Fe₃C Diagram.(10 marks) 3(b) What is the difference between case hardening and surface hardening? Explain pack carbonizing.(10 marks) 4(a) Draw and explain construction of Time Temperature Transformation (TTT) diagrams of 0.8% C alloy.(10 marks) 4(b) Derive an expression for Griffith theory of brittle fracture. Explain Orowan's Modification.(10 marks) 5(a) What is plastic deformation? Distinguish between slip and twin mechanism of plastic deformation.(10 marks) 5(b) Classify crystal Imperfections. Distinguish between slip and twin mechanism of plastic deformation.(10 marks)

Write short note on any four

6(a) Composite materials(5 marks) 6(b) Ausforming(5 marks) 6(c) Yield point phenomenon(5 marks) 6(d) Harden ability test(5 marks) 6(e) Normalizing(5 marks)