Burgers vector-dislocation line orientations for edge

1. Cite the relative Burgers vector-dislocation line orientations for edge, screw, and mixed dislocations.

2. For an FCC single crystal, would you expect the surface energy for a (100) plane to be greater or less than that for a (111) plane? Why? (Note: You may want to consult the solution to Prob- lem 3.53 at the end of Chapter 3.)

3. For a BCC single crystal, would you expect the surface energy for a (100) plane to be greater or less than that for a (110) plane? Why? (Note: You may want to consult the solution to Problem 3.54 at the end of Chapter 3.)

4. (a) For a given material, would you expect the surface energy to be greater than, the same as, or less than the grain boundary energy? Why?

(b) The grain boundary energy of a small- angle grain boundary is less than for a high- angle one. Why is this so?