ANNA UNIVERSITY EXAM QUESTION PAPAER
B.E. DEGREE EXAMINATION.
IV Semester Metallurgical Engineering
MECHANICAL BEHAVIOUR AND TESTING OF MATERIALS
Time : Three hours Maximum : 100 marks
Answer ALL questions.
PART A — (10 ´ 2 = 20 marks)
1. Define Strain Hardening.
2. Compare edge and screw dislocation.
3. Sketch a tensile test specimen showing all dimensions in mm.
4. What type of grips are provided in a torsion testing machine to fix the specimen?
5. List out the different types of Hardness testing machines.
6. What property of metal does the impact test measure? Give its significance.
7. What is true stress? How to determine the same?
8. Define Endurance limit.
9. Sketch and mark the various stages in creep.
10. What are the four basic variables involved in creep tests?
PART B — (5 ´ 16 = 80 marks)
11. Explain different types of fatigue stress cycle, stresses and ratios.
12. (a) Explain strengthening mechanism due to dislocations with neat sketches.
(b) List out the types of deformations in metals. With a neat sketch explain any one type of plastic deformation.
13. (a) State the working principle of the machine used for tension test. What care should be taken while performing a test on UTM?
(b) State the importance of torque–twist curve and explain how to determine modulus of rigidity from torque–twist curve.
14. (a) Explain the working principles of machines used to conduct Charpy and Izod impact test. How specimens are put–up in both the tests? Why?
(b) Discuss the factors considered for selection of hardness testing machine. What care must be taken while selecting specimens for hardness test.
15. (a) Define fracture. Explain the types of fracture. Which type of fracture is preferable? Why?
(b) Discuss the following :
(i) Notch effects on fracture
(ii) Stages in the formation of ductile fracture.