Q.1
The following creep map is plotted with homologous stress and temperature, as shown in the region. The coble creep region is shown by region ________
Questionmechanical-metallurgy-questions-answers1.jpg
  • a) I
  • b) II
  • c) III
  • d) V
Q.2
The following creep map is plotted with homologous stress and temperature, as shown in the region. The Nabarro-Herring creep region is shown by region ________
Questionmechanical-metallurgy-questions-answers2.jpg
  • a) I
  • b) II
  • c) III
  • d) V
Q.3
The following creep map is plotted with homologous stress and temperature, as shown in the region.
Questionmechanical-metallurgy-questions-answers3.jpg
  • a) I
  • b) II
  • c) III
  • d) IV
Q.4
If the strain rate on the material increases, the Coble creep region of the creep map will _________
  • a) increase and the curve will shift upwards
  • b) increase and the curve will shift towards the right
  • c) decrease and the curve will shift downwards
  • d) decreases and the curve will shift towards left
Q.5
The steady-state creep activation energy is given by the Arrhenius type rate equation ε = Ae-(Q/RT), where,
  • a) Q/R
  • b) Q/2.3R
  • c) A/Q
  • d) A/2.3R
Q.6
The activation energy of creep for a pure metal at high temperature is equal to activation energy of _____________
  • a) interstitial diffusion
  • b) substitutional diffusion
  • c) self-diffusion
  • d) grain growth
Q.7
The creep deformation rate of gamma iron is higher than alpha iron because the gamma iron is high-temperature phase.
  • a) True
  • b) False
Q.8
The two necessary conditions for superplasticity is higher temperature and low strain rate of deformation.
  • a) True
  • b) False
Q.9
The applied flow stress to cause the superplasticity of the material has to be ___________
  • a) very large
  • b) large
  • c) small
  • d) very small
Q.10
The superplasticity is reduced by the presence of the second phase particle in the matrix.
  • a) True
  • b) False
Q.11
The grain shape in the superplastic material is generally __________ and remains ___________ even after deformation.
  • a) elongated, equiaxial
  • b) acicular, elongated
  • c) equiaxial, equiaxial
  • d) irregular, elongated
Q.12
The strain rate sensitivity (m) in the superplastic material is __________
  • a) 0
  • b) 1
  • c) 0.5
  • d) 10
0 h : 0 m : 1 s