Q.1
The yield point can be completely recovered in a zinc crystal at _____
  • a) room temperature
  • b) 32⁰C
  • c) 50⁰C
  • d) 88⁰C
Q.2
Polygonization is associated with_____
  • a) grain size
  • b) plastically bent crystals
  • c) conductivity
  • d) strength of the material
Q.3
Polygonization is a process of _____
  • a) annealing a bent crystal
  • b) annealing a pure metal
  • c) heating the metal above recrystallization temperature
  • d) quenching
Q.4
The regrouping of edge dislocations into low-angle boundaries helps in _____
  • a) lowering the strain energy
  • b) increasing the stored energy
  • c) lowering the recrystallization temperature
  • d) increasing the strength of the metal
Q.5
An edge dislocation is capable of moving by a climb in a direction _____ to the slip plane.
  • a) 30⁰
  • b) 45⁰
  • c) 90⁰
  • d) 180⁰
Q.6
The rate of polygonization increases rapidly with _____
  • a) density
  • b) temperature
  • c) humidity
  • d) grain size
Q.7
As the polygon walls become more widely separated, the rate of ______becomes a decreasing function of time and temperature.
  • a) polygonization
  • b) decay
  • c) coalescence
  • d) grain growth
Q.8
The rate at which a recovery process occurs always decreases with _____
  • a) temperature
  • b) time
  • c) yield strength
  • d) ductility
Q.9
In deformed polycrystalline metals, high-temperature recovery is considered to be essentially a matter of polygonization.
  • a) True
  • b) False
Q.10
Recrystallization during an isothermal anneal begins very slowly.
  • a) True
  • b) False
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