1. Consider two edge dislocations of opposite sign and having slip planes separated by several atomic distances. Is it possible for two screw dislocations of opposite sign to annihilate each other? Explain your answer. (10 points) 2. Consider a metal single crystal oriented such that the normal to the slip plane and the slip direction are at angles of 43.1 and 47.9, respectively, with the tensile axis. If the critical resolved shear stress is 20.7MPa(3000psi), will an applied stress of 45MPa(6500psi ) cause the single crystal to yield? If not, what stress will be necessary? (20 points) 3. Describe the three strengthening mechanisms (grain size reduction, solid-solution strengthening, and strain hardening). Be sure to explain how dislocations are involved in each of the strengthening techniques. (20 points) 4. (a) What are the differences between the recovery and recrystallization processes? (b) Explain the differences in grain structure for a metal that has been cold worked and one that has been cold worked and then recrystallized. (20 points) 1. Consider two edge dislocations of opposite sign and having slip planes separated by several atomic distances. Is it possible for two screw dislocations of opposite sign to annihilate each other? Explain your answer. (10 points) 2. Consider a metal single crystal oriented such that the normal to the slip plane and the slip direction are at angles of 43.1 and 47.9, respectively, with the tensile axis. If the critical resolved shear stress is 20.7MPa(3000psi), will an applied stress of 45MPa(6500psi ) cause the single crystal to yield? If not, what stress will be necessary? (20 points) 3. Describe the three strengthening mechanisms (grain size reduction, solid-solution strengthening, and strain hardening). Be sure to explain how dislocations are involved in each of the strengthening techniques. (20 points) 4. (a) What are the differences between the recovery and recrystallization processes? (b) Explain the differences in grain structure for a metal that has been cold worked and one that has been cold worked and then recrystallized. (20 points)