B.TECH - Semester 4 metallurgy and materials science Question Paper 2019 (jun)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- Explain the attributes of slip system.
- What are the effects of surface defects on crack initiation?
- Explain the effects of grain boundary on dislocation movement.
- Explain two reasons why interstitial diffusion is normally more rapid than vacancy diffusion.
- Correlate the significance of dislocation density to a guitar wire.
- What are the special features of marternsite?
- Distinguish between hardness and hardenability?
- Why cast Irons are brittle?
- What is HSS? Identify 18:4:1.
- Describe the composition, properties, and use of Bronze and Gun metal. $$ (10 \times 2=20 \text { Marks }) $$ P.T.O.
- (a) What is meant by work hardening? Explain work hardening process on stress - strain curve of a ductile material.
- (b) Explain with neat sketch, the changes occurring on a work hardened material subjected to heat treatment process. Name the type of process employed.
- Explain Hall-Petch relation. Explain the effect of fine and coarse grain sizes on mechanical strength at room temperature and creep applications.
- Postulate with neat sketches, why $100 \%$ pure metals are weak in strength? What is the primary function of adding alloying elements into pure metals? Explain the effects of adding alloying elements in interstitial and substitution solid solutions w...
- Explain in detail the ductile to brittle transition temperature and correlate the Titanic ship disaster with DBTT.
- (a) What is the need of surface hardening process? What is the minimum percentage of carbon required during the process of surface hardening?
- (b) Explain a suitable surface hardening process which changes the composition of the surface layers with the help of neat sketches. OR -16. Explain various phase transformations and reactions which occur during the cooling of $0.2 \%$ carbon alloy ...
- Explain the fundamental effects of alloying elements in steel on polymorphic transformation temperatures, grain growth, eutectoid point, retardation of the transformation rates, formation and stability of carbides.
- Explain the classification of cast iron giving their composition, microstructure, properties and uses. Correlate the microstructure with properties. ( $\mathbf{4} \boldsymbol{\times} \mathbf{2 0} \boldsymbol{=} \mathbf{8 0}$ Marks)
- 403 : METALLURGY AND MATERIAL SCIENCE (MP) Time : 3 Hours Max. Marks 100 PART - A Answer all questions :
- Differentiate between superconductivity and superplasticity.
- Obtain the atomic packing factor for a BCC structure.
- Is iron an allotropic metal? Explain.
- What is a solid solution? What are the different types of solid solutions? Give examples for each.
- Explain the TTT diagram for eutectoid steel.
- What metallurgical changes occur when a previously work hardened material passes through recrystallization and grain growth phases?
- What is the significance of performing impact test on a metallic specimen?
- What are the different stages in a ductile fracture?
- Sketch and explain a typical creep curve.
- Explain the composition and uses of any two alloys of aluminium. ( $\mathbf{1 0} \boldsymbol{\times} \mathbf{4} \boldsymbol{=} \mathbf{4 0}$ Marks) P.T.O. Answer any one full question from each Module.
- (a) Sketch and explain the various line and surface defects in a crystal.
- (b) How are crystallographic planes and directions specified? Sketch (101), (110), and (011) planes in a cubic unit cell.
- (a) Explain the mechanism of dislocation and twinning in the plastic deformation of a metal.
- (b) What is the importance of Burger's vector and Frank Read source in dislocation?
- (a) What is an equilibrium diagram? How are equilibrium diagrams for binary alloys classified based on mutual solubility in liquid and solid phases? Give examples for each type.
- (b) What is hardenability? Explain the standard Jominy end quench test for determining hardenability.
- (a) Why surface hardening is required? How does it differ from a conventional hardening process? Explain the differences between carburizing, nitriding and cynading.
- (b) Explain the eutectoid reaction in the iron-carbon equilibrium diagram. Write a note on the microconstituents mentioned in this reaction.
- (a) Explain Griffith's crack theory and obtain an expression for critical fracture size for the crack to propagate.
- (b) What is ductile to brittle transition in steel? What are the factors affecting it?
- (a) Why there is a poor correlation between fatigue strength of a material obtained from lab tests and actual service failures?
- (b) How do alloying elements alter the general properties of steel?