Microstructure characterization of 7050 aluminum alloy during dynamic recrystallization and dynamic recovery

Dynamic recrystallization and dynamic recovery in 7050 aluminum alloy during high temperature deformation have been investigated by tensile tests conducted at 460 degrees C and strain rates of 1.0x10(-2) and 0.1 s(-1). It is shown that continuous dynamic recrystallization and dynamic recovery are the softening mechanisms when strain rates are 1.0 x 10(-2) and 0.1 s(-1), respectively. The increase in the average misorientation angle is proportional to the increase in the true strain during continuous recrystallization and dynamic recovery. The grain size of the 7050 aluminum alloy increases with increasing true strain during continuous dynamic recrystallization and dynamic recovery, while the aspect ratio of grains remains unchanged after the continuous dynamic recrystallization; and it increases with the true strain during dynamic recovery. The continuous increase of the average misorientation angle during continuous dynamic recrystallization is attributed to the migration of subgrain boundaries and the absorption of dislocations into grain boundaries (C) 2007 Elsevier Inc. All rights reserved.