Processing maps for the Cu-Cr-Zr-Y alloy hot deformation behavior

Abstract

Hot deformation behavior of the Cu-Cr-Zr-Y alloy was studied by hot compressive tests in the 650–850°C temperature and 0.001–10s−1 strain rate ranges using the Gleeble-1500D thermo-mechanical simulator. The flow stress behavior and microstructure evolution were observed during the hot deformation process. The peak stress increases with decreasing temperature and increasing strain rate. The apparent activation energy for hot deformation of the alloy is 336kJ/mol. Based on the dynamic material model, the processing maps for the alloy were obtained at 0.3, 0.4 and 0.5 strain. The evolution of dynamic recrystallization microstructure strongly depends on the deformation temperature and strain rate. Dynamic recovery is the main softening mechanism at low temperature and high strain rate. Dynamic recrystallization appears at high temperatures and low strain rates. The precipitates of chromium-rich particles were observed during hot deformation. The addition of Y can refine the grain and effectively improve the hot workability of the Cu-Cr-Zr alloy. According to the processing maps and microstructure observations, the optimal hot working parameters for the Cu-Cr-Zr-Y alloy are 800–850°C temperature range and 0.01–1s−1 strain rate range.