a) Aluminum sheet is to be rolled according to the following parameters: starting thickness 1 mm, reduced thickness 0.8 mm, yield strength 70 MPa. What roll radius should be chosen to keep the forming pressure below 150 MPa? [1 Mark]
b) Describe the processes of recovery and recrystallization that occur during the high-temperature annealing of a work-hardened metal. How does the grain size of the fully recrystallized metal depend on the initial amount of work hardening? Mention some practical situations in which recrystallization is important. [2 Marks]