Microstructure and properties evolution of single crystal copper during strong cooling deformation annealing process

The single crystal copper after strong cooling deformation can produce obvious sub-structure, which will transform in the annealing process. The research investigates microstructure evolution of the strong cooling deformed single crystal copper in different annealing process systems and its recrystallization process by means of metallographic, mechanical properties test and resistance test. The results show that: the recrystallization temperature of single crystal copper wire begins at 250 ℃,which is 50 ℃ higher than that of the SCR continuous casting copper rod. The recrystallization incubation period of single crystal copper decreases with the increase of temperature, and the incubation period is less than 2 min at 500 ℃. Single crystal copper conductive performance improves in the recovery phase, but recrystallization caused by higher temperature will slow the resistivity decreasing trend due to the increasing number of grain boundaries. It is unavoidable for the strong cooling deformed single crystal copper to become polycrystalline, if it tends to regain sufficient plasticity. High temperature and ultra-short time annealing will help to restore the plasticity and electrical conductivity of single crystal copper, and maintain its morphology as well.