ENGINEERING MATERIALS AND METALLURGY PAPER 2

DOWNLOAD MECHANICAL ENGINEERING PREVIOUS YEARS QUESTION PAPERS B.TECH PTU SECOND YEAR

ENGINEERING MATERIALS & METALLURGY ME 202/205 4th Sem. May 2k5

Note: Section A is compulsory. Attempt any Four questions from Section B and two from Section C

Section A Marks 2 each

1.

1. What is the difference between ceramic and polymer?
2. Calculate the number of atoms in FCC structure.
3. Define Polymorphism.
4. What do you mean by Recrystallization?
5. What is Phase Rule?
6. Find degree of freedom at triple point.
7. Draw crystal structure of martensite.
8. Name two non-equilibrium phases of iron-carbon alloy.
9. Define true stress.
10. Why is tempering treatment done after quenching?

Section B Marks 5 each

2. Draw [2 1 1] and (2 2 1) in BCC unit cell.

3 What do you mean by imperfect lattice? How many types of crystal defects occur in materials? Describe them.

4. How does plastic deformation occur? Describe their mechanism. What is difference between thermal and mechanical twins?

5. Find the line energy of dislocation in BCC structure. The shear modulus of material is 80.2 GN/m2 and lattice constant is 2.87 Å.

6. What are different equilibrium phase reactions that occur in phase diagram? Describe them. Draw a peritectic phase diagram and mark all points and lines.

Section C Marks 10 each
7. (a) What are annealing and normalizing treatments? Explain why hypereutectoid steel is not given full annealing treatment?
(b) What is T-T-T diagram? Describe how it is obtained. Mention its importance.

8. Draw a hypothetical phase diagram A-B with the help of following data:
(a) Melting point of A = 1100 oC
(b) Melting point of B = 1300 oC
(c) Eutectic reaction occurs at 1000 oC at 40% B composition.
(d) maximum solubility of B in A and A in B at eutectic temperature in 10% and 5% respectively which drops down to zero at 0 oC.

Mark each line and area. How the structure of alloy will change if alloy containing 10% B composition is cooled from liquid state?
9.. Write short notes on any two of the following:
(a) surface hardening processes
(b) Ferrite stabilizer in steels.
(c) Hardenability and its measurement.