Hot deformation characteristics and dynamic recrystallization of biomedical CoCrWCu alloy

Abstract

In order to explore the dynamic recrystallization of biomedical CoCrW-2Cu alloy, the hot deformation behavior was investigated by isothermal compression tests. True stress-true strain curves showed that the true stress increased with increasing strain rate or decreasing deformation temperature. Meanwhile, obvious dynamic softening was observed. The constitutive equation and processing maps were constructed to elucidate the relationship between true stress and deformation parameter. The phase component and microstructure were investigated to reveal the relationship between microstructure evolution and deformation condition, which was beneficial to the optimization of the hot deformation parameter. The variation of deformation condition has a limited influence on the phase component. The strain rate has a significant influence on the extent of recrystallization. An obviously discontinuous dynamic recrystallization (DDRX) process was occurred in this study. Furthermore, the extent of dynamic recrystallization (DRX) of sample deformed at 1100 °C/0.01 s -1 was the highest. Negative value of efficiency of power dissipation could be found in the top left corner of processing maps, while high value of efficiency of power dissipation was observed in the region with high temperature and low strain rate. The processing maps predicted that the optimized deformation parameters were 1100~1150 °C and 0.01~0.1 s -1 .