Zr元素对Cu-4Ti合金调幅分解与非连续沉淀的影响

Effect of Zr addition on the spinodal decomposition and discontinuous precipitation of Cu-4Ti alloy

摘要:

Cu-Ti合金热处理过程中发生调幅分解而产生强烈的时效强化效应，获得较高的强度与硬度，但Cu-Ti合金极易过时效而使强度与硬度下降，需要添加改性元素。本文研究了Zr元素对Cu-4Ti合金调幅分解与非连续沉淀的影响,使用光学显微及透射电镜表征了合金固溶及热处理过程的微观组织，分析了Zr元素对调幅分解与非连续沉淀组织形貌的影响。通过力学及电学性能的变化，分析了Zr元素对合金性能的影响。结果表明：Zr元素阻碍Ti原子的扩散，能显著延缓Cu-4Ti合金调幅分解的过程，抑制非连续沉淀的发生，提高Cu-4Ti-0.1Zr合金在峰值时效（450℃?h）时的综合性能，对电导率的影响小，其抗拉强度为1155MPa，维氏硬度为330，电导率是15.4 IACS%。

Abstract:

The Cu-Ti series alloys, strengthen by the spinodal decomposition during the heat treatment, are easy of losing strength and hardness after over aging, which need to add elements to optimize them. The effect of 0.1wt% zirconium addition on the spinodal decomposition and discontinuous precipitation of Cu-4Ti alloy has been studied. Microstructure was investigated by Optical Microscope (OM) and Transmission Electron Microscope (TEM). Mechanical properties and electrical conductivity (EC) were tested to show the properties of these alloys. The results show that spinodal decomposition process was retarded and discontinuous precipitation was suppressed by 0.1 wt% zirconium added to Cu-4Ti alloys, because of the hindering of zirconium to titanium’s diffusion. Zirconium elevated the properties of this alloy on peak aging at 450℃ for 7h. The zirconium has little influence on electrical conductivity of the Cu-4Ti-0.1Zr alloy. The tensile strength was 1155 MPa, microhardness was 330 and the electrical conductivity was 15.4%IACS.