ECAP及后续退火对Cu­Mg合金组织与性能的影响

摘要

采用等通道转角挤压(ECAP)和后续热处理对高铁接触导线用铜镁合金进行微观组织调控以获得优良的综合性能。结果表明：Cu­0.2%Mg(质量分数)和Cu­0.4%Mg合金在200℃下经多道次ECAP加工后，其晶粒组织明显细化，微观硬度和抗拉强度提高明显，同时仍保持了良好的导电率和伸长率。ECAP加工后Cu­Mg合金经不同温度退火后，其力学性能有较明显的下降，而导电率和伸长率有所提高。与 Cu­0.2%Mg 合金相比，Cu­0.4%Mg合金具有更好的抗高温软化能力。%The microstructures of Cu­Mg alloys used for high­speed railway contact wire were changed and controlled to obtain excellent overall performance via equal channel angular pressing (ECAP) and subsequent annealing. The results show that multi­pass ECAP at 200 ℃ makes the grain size of Cu­0.2%Mg (mass fraction) and Cu­0.4%Mg alloys obviously refine, which significantly improves their micro­hardness and tensile strength while maintain their good electrical conductivity and elongation. After annealing at different temperatures, the mechanical properties of the ECAP Cu­Mg alloys are obviously declined but their electrical conductivity and elongation are increased. The Cu­0.4%Mg alloy has better resistance of high temperature softening than the Cu­0.2%Mg alloy.