In which of the following processes does recovery, recrystallization, grain growth take place?
  • a) Surface hardening
  • b) Tempering
  • c) Strengthening
  • d) Annealing
When a material is plastically deformed at low temperature(arounddegrees) relative to the melting temperature, which of the following change isn’t observed?
  • a) Change in grain shape
  • b) Strain hardening
  • c) Decrease in dislocation density
  • d) Increase in dislocation density
At which of the following temperature can recovery occur? (where Tm is melting point)
  • a) 0.2Tm
  • b) 0.4Tm
  • c) 0.5Tm
  • d) 0.6Tm
Strain-relief crystallization takes place when deformed metals are heated.
  • a) True
  • b) False
Which of the following statements are false in strain-relief crystallization?
  • a) Dislocation climb
  • b) Decrease in the electric resistance
  • c) Increase in density
  • d) Interaction of like signed dislocation
By what percentage can the hardness decrease after strain-relief crystallization?
  • a) 12%
  • b) 5%
  • c) 8%
  • d) 17%
In which of the following metal polygonization rarely takes place?
  • a) Copper
  • b) Iron
  • c) Aluminium
  • d) Molybdenum
Which of the following processes can be used to refine the grain structure?
  • a) Recovery
  • b) Recrystallization
  • c) Grain growth
  • d) Such a process does not exist.
Lowest temperature for recrystallization for iron is 270°C
  • a) True
  • b) False
Which of the following is false for grain growth?
  • a) The grains start growing
  • b) Grain growth accelerates with increase in temperature
  • c) Decrease in free energy
  • d) Increase of surface energy
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