Hot deformation behavior of Cu-Fe-P alloys during compression at elevated temperatures

摘要

Hot compression tests of the Cu-Fe-P alloys (KFC alloy and C194 alloy) were performed on Gleeble 1500 system at strain rates ranged between 0.01 and 10 s{sup}(-1) and temperatures between 650 and 850 ℃. The results show that the flow stress and deformed microstructure strongly depend on the Fe contents. For the KFC alloy, the true stress-true strain curves are characterized by multiple peaks or a single peak flow, followed by a steady state flow stress, mainly related to dynamic recrystallization. For C194 alloy, the true stress-true strain curves exhibit a peak stress in the initial stage of deformation, after which the flow stress decreases monotonically, dynamic particles coarsening seemed to be responsible for flow softening. The values of deformation activation energy for the KFC alloy and the C194 alloy are 289 and 316 kJ/mol, respectively. Both are higher than that of the polycrystalline copper. The increase of deformation activation energy of the Cu-Fe-P alloys is due to the existence of the Fe-rich particles, which act as obstacles for the dislocation movement, and lead to a increase of the flow stress.