SUBSTRUCTURAL INFLUENCE IN THE HOT-ROLLING OF AL-ALLOYS

The industrial rolling of aluminum alloys is generally conducted in mu ltistage schedules of 10-15 passes partly on reversing mills and partl y on continuous mills with temperature declining from 500 degrees C to between 300 degrees C and 250 degrees C. Static recrystallization may take place in long intervals after passes with higher temperature and strain. During lower temperature intervals, only static recovery take s place so that in the following passes the flow curves exhibit higher initial stresses. Dynamic recovery decreases gradually through the ho t-, warm-, and cold-working ranges but is reduced as the concentration of solutes and particles increase. Recrystallization is much more sen sitive to temperature and alloying and is retarded by increased dynami c recovery. The texture of sheet depends on lattice-dependent Taylor r otations during dislocation slip, enhanced recovery of certain deforma tion band orientations, and preferred nucleation and growth during int erpass pauses or annealing. Schedule optimization can be guided by phy sical simulation or modeling based on recrystallization kinetics to at tain selected strengthening substructure, recrystallized grain size, a nd texture for product earing control.