Mechanical Metallurgy Mock Test 7

1. The cycle ratio is defined as _____________

2. The material with higher stacking fault energy has higher fatigue strength whereas the material with lower stacking fault will have a lower fatigue limit.

3. Is it possible that the material which shows the fatigue limit in normal environment does not show any endurance limit in a corrosive environment.

4. Typically the creep rate is measured in which unit?

5. The correct graph to show the relationship between the crack growth rate (da/dN) vs stress intensity factor range (ΔK) is shown in the figure ________

6. If the material is expanded elastically with very high rate, such that there is no thermal equilibrium between the material and surrounding, and also the expansion is adiabatic (no exchange of heat). The temperature of the material with strain will __________

7. If the sample is tested for a large number of cycles below its fatigue limit and the stress is gradually increased above the fatigue limit, the true fatigue limit of material will _______

8. Which stage of the fatigue crack is most significant in the high cycle fatigue?

9. The ductile material gives best result in the high strain amplitude or high cycle fatigue, while the strong material gives best result in high-stress low cycle fatigue.

10. A steel component was loaded at 300MPa for 500 cycles, then at 200 MPa it is run for 100 Cycle and rest of the life it is loaded 100 MPa. Find the total number of cycles the component has run before failing?