Compression Deformation Behavior and Processing Map of Pure Copper

Abstract

To reveal compression deformation behavior of pure copper, the deformation characteristics of pure copper have been investigated by means of compression tests in the temperature range of 400–900°C and strain rate range of 0.001–1 s⁻¹. The results show that the flow stress of pure copper increases with increasing strain rate and decreasing deformation temperature, which is characterized by work-hardening, dynamic recovery, dynamic recrystallization, and secondary work-hardening, etc. The activation energy of hot deformation is associated with deformation temperature and strain rate, and the average activation energy is calculated to be 303.8 kJ/mol. The flow stress prediction model based on GA+BP possess, is in very good agreement with the true stress curve, which is of significance to the guidance of hot working of pure copper. The flow instability occurs in the intermediate strain rate region (0.01–0.1 s⁻¹) base on the analysis of processing map, the high power dissipation correspond to the dynamic recrystallization. Appropriate reducing the deformation temperature or increasing the strain rate is beneficial for the grain refinement in the steady-state region of the processing map.