强变冷形单晶铜线退火过程组织性能演变研究

经强冷变形后的单晶铜线会产生明显的亚结构。在退火过程中该亚结构将发生转变．以中拉单晶铜线为对象，通过金相、力学性能测试法、电阻测试等手段研究了经强冷变形后的单晶铜线在不同退火工艺制度下的组织性能变化和再结晶过程．研究结果表明：加工态单晶铜线材的再结晶温度开始在250℃左右，比相同冷变形率下的SCR连铸纯铜杆的再结晶温度高约50℃．强冷变形单晶铜线再结晶形核的孕育期随温度升高而缩短．500。C时的孕育期不足2min．单晶铜在退火的回复阶段导电性能得到改善，但温度较高发生再结晶时，由于晶界数量的不断增加，有抑制电阻率减小的作用．强冷变形后的单晶铜线要想恢复足够的塑性，则难以避免成为多晶，如果既要恢复单晶铜线的塑性和导电性，又要维持单晶的组织形态，进行高温超短时间退火将有助于解决这一问题．

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 ~C,which is 50 ~C 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 ~C. 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.