Time Allowed: 03:00 hrs Max.Marks: 100
1. This paper contains 8 questions.
2. Question number 1 is compulsory.
3. Attempt any 5 questions from Q2 to Q8.
4. Attempt all the parts of the question chosen.
5. The marks assigned to each question are shown at the end of the question in square brackets.
6. Do not write anything on the question paper except your registration number at the designated space.
7. Answer all the questions in serial order.
Question 1. (a) What is strain rate? How does it affect the mechanical behavior of polymeric and metallic materials? [2 Marks]
(b) What are the coordination numbers for octahedral and tetrahedral sites? [2 Marks]
(c) Give two significance of dislocations. [2 Marks]
(d) Define the term: nucleation, embryo, heterogeneous nucleation. [2 Marks]
(e) What is a Isomorphous phase diagram? [2 Marks]
(f) What is intermetallic compound? [2 Marks]
(g) What is age hardening? [2 Marks]
(h) What is strain hardening? [2 Marks]
(i) What is a stainless steel? Why are stainless steels stainless? [2 Marks]
(j) How do you change the morphology of Iron carbide in steels and what are the consequences if it is changed so? [2 Marks]
(k) Define cast iron using iron-carbon phase diagram. [2 Marks]
(l) What is the principle of surface hardening of steel using carburizing and nitriding? [3 Marks]
Question 2. With neat sketch explain Fe- Fe3C phase equilibrium phase diagram. [15 Marks]
Question 3. Explain the effects of Alloying elements added to steels? [15 Marks]
Question 4. Explain different conditions for unlimited solid solubility? [15 Marks]
Question 5. For a 99.6 wt% Fe-0.40 wt% C at a temperature just below the eutectoid, determine the following
a) Composition of Fe3C and ferrite (a)
b) The amount of carbide (cementite) in grams that forms per 100 g of steel the amount of pearlite and proeutectoid ferrite (a) [15 Marks]
Question 6. What are the different types of cast irons? Explain using a sketch. [15 Marks]
Question 7. a) Using a stress-strain diagram, explain what the term “strain hardening” means.
b) Write down the equation that defines percentcold work. Explain the meaning of each term.
c) A 0.625-cm-thick copper plate is to be coldworked 63%. Find the final thickness. [15 Marks]
Question 8. Find the atomic packing factors for BCC, FCC and HCP? [15 Marks]
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