JNTU Exam Papers,II BTech I Sem Supplimentary Exam, Physical Metallurgy,February 2008
JNTU Exam Papers
1. (a) Name various methods of illumination in metallurgical microscope and briefly explain each one of them.
(b) What is conical stop illumination? Discuss its features.
2. (a) Define planar density and estimate the planar density value of (111) plane in BCC and FCC unit cells. Support with due calculations.
(b) Which crystallographic planes directions in BCC, FCC and HCP structures have highest atomic density?
3. (a) Distinguish between a commercially pure metal and an alloy.
(b) An alloy is more useful than pure metal? Discuss.
(c) What is a master alloy? What are its chief characteristics?
(d) What is an interstitial solid solution? Name the five elements which commonly form interstitial solid solutions.
4. Explain how a cooling curve is determined. What significant information can be obtained from a cooling curve? Explain the significance of a hold, a break and a recovery in a cooling curve.
5. (a) What is allotrophy? What is allotrophic transformation? Give any three examples which show allotrophic transformation and explain them.
(b) Explain the allotropic transformation of Iron.
6. Draw neatly Al-cu phase – diagram. Label the various phase in it. Explain the important features in the diagram.
7. (a) Distinguish fully between Martensite and Bainitic transformations.
(b) Explain the term Quenching. Which quenching media are used in the heat treatment of steels? Discuss what do you mean by severity of quench.
(c) Discuss about the phase ‘Episilon carbide’.
8. (a) What is S curve? How do you draw it? Classify the types of ‘S’ curves. Give
at least three heat treatment cycles in which ‘S’ curves find direct applications.
(b) Discuss the factors affecting the ‘S? curves.