Structure property relationships For the following changes

Structure - property relationships : For the following changes in structure indicates the accompanying change in mechanical property by circling the appropriate symbol:

2. For the following change in structure indicate the accompanying change in mechanical property by circling the appropriate symbol: t (increases), t eases). does not change). 2.1. Reducing grain size t a materials hardness. 2.2. Increasing dislocation density t a materials shear modulus. 2.3. Increasing the mean stress during cyclic loading t the endurance limit 2.4. Reducing grain size t a materials resistance to diffusional creep 2.5. Increasing the Young\'s modulus of the reinforcing fiber in a fiber composite t the fraction of load carried by the reinforcing phase.

Solution

1. Increase in strength of material with decrease in grain size is due the fact that one of the major strengthening mechanisms applicable in poly-crystalline materials (composition being a constant factor), grain boundary strengthening comes into play. so hardness increases/.

2.Increasing the dislocation density increases the yield strength which results in a higher shear stress required to move the dislocations. so shear modulus increases.

3. endurance limit decrease as material may fail due to fatigue.

4. creep rate decreases with increase in grain size.

5.increase the fraction of load on fibre