Hot deformation behavior of Cu-Ni-Si alloy at elevated temperature

Hot compression tests of Cu-Ni-Si alloy with high Ni and Si contents were carried out on Gleeble-3800 thermal simulator in the deformation temperature of 750 degrees C similar to 950 degrees C, strain rate of 0.01 similar to 10 s(-1) and deformation amount of 70%. Subsequently, constitutive equation based on Arrhenius-type constitutive model considering strain effect was established, and the average absolute relative error and correlation coefficient R were 7.34% and 0.991. Then, hot Processing map was obtained by combining the power dissipation and instability maps, and the suitable processing conditions could be predicted. Based on the results of these experimental and theoretical investigations on the hot deformation behavior of Cu-Ni-Si alloys, Multi-direction compression (MDC) was carried out at 860 degrees C and corresponding strain of single pass and accumulated 24 passes 0.4 and 9.6 respectively. The resulted microstructure consisted of fine matrix grains with a diameter of 3.02 mu m and well dispersed Ni31Si12 particles 0.62 mu m, suggesting that the results of thermal simulator and corresponding calculation were credible for guiding the thermo-mechanical processing parameters of Cu-Ni-Si alloys.