Hot deformation behavior and processing map of Cu-Ni-Si-P alloy
(1. College of Materials Science and Engineering,
Henan University of Science and Technology, Luoyang 471003, China;
2. College of Materials Science and Engineering,
University of Shanghai for Science and Technology, Shanghai 200093, China)
Henan University of Science and Technology, Luoyang 471003, China;
2. College of Materials Science and Engineering,
University of Shanghai for Science and Technology, Shanghai 200093, China)
Abstract: The high-temperature deformation behavior of Cu-Ni-Si-P alloy was investigated by using the hot compression test in the temperature range of 600-800 °C and strain rate of 0.01-5 s-1. The hot deformation activation energy, Q, was calculated and the hot compression constitutive equation was established. The processing maps of the alloy were constructed based on the experiment data and the forging process parameters were then optimized based on the generated maps for forging process determination. The flow behavior and the microstructural mechanism of the alloy were studied. The flow stress of the Cu-Ni-Si-P alloy increases with increasing strain rate and decreasing deformation temperature, and the dynamic recrystallization temperature of alloy is around 700 °C. The hot deformation activation energy for dynamic recrystallization is determined as 485.6 kJ/mol. The processing maps for the alloy obtained at strains of 0.3 and 0.5 were used to predict the instability regimes occurring at the strain rate more than 1 s-1 and low temperature (≤650 °C). The optimum range for the alloy hot deformation processing in the safe domain obtained from the processing map is 750-800 °C at the strain rate of 0.01-0.1 s-1. The characteristic microstructures predicted from the processing map agree well with the results of microstructural observations.
Key words: Cu-Ni-Si-P alloy; hot compression deformation; dynamic recrystallization; constitutive equation; processing maps