Influences of Strain Rate and Load Direction on the Thermo-mechanical Behavior of a Nano-Alumina-Containing Copper Alloy Bar

The effects of strain rate and load direction on the thermo-mechanical behavior of Cu-2.7vol.%Al 2 O 3 alloy bar with high strength and electrical conductivity were investigated. The results show that the thermo-mechanical behavior of the alloy changes greatly with changing load direction or strain rate. For the same compression strain rate, the peak yield stress in the longitudinal compression is much higher than that of transverse compression. The homogeneous distribution of dynamic recrystallization grains or subgrains after longitudinal compression is much higher than that of transverse compression. For the longitudinal or transverse compression, the size of dynamical recrystallization grains decreases with increasing strain rate, the initial elongated bands can only be observed in the transverse compressions due to the effect of load direction. The flow stress oscillation phenomenon appears in both transverse and longitudinal compressions with a strain rate of 20 s −1 . Accordingly, the relationship between flow stress and microstructure, and a model of dynamic recrystallization in the transverse and longitudinal compressions, were established and analyzed in this paper.