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 ________
- 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 ________
- 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.
- 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