中文摘要：

研究Ni的添加及时效处理对Cu.3Ti合金组织与性能的影响。采用光学显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)及高分辨透射电子显微镜(HRTEM)对Cu.3Ti.1Ni合金的组织和析出相进行表征，并对其硬度和导电率进行测试。结果表明：Ni的添加导致铸态Cu.3Ti合金在凝固过程中形成NiTi相，组织由树枝晶转变为等轴晶。时效处理后析出共格的亚稳定β'-Cu4Ti相，过时效导致β'-Cu4Ti相转变为非共格的层片稳定相Cu3Ti。同时，时效处理导致出现了退火孪晶，且在合金基体中发现位错线的聚集。Ni的添加提高了Cu.3Ti合金的导电率，降低了其硬度。在实验范围内，Cu.3Ti.1Ni合金的最佳时效处理工艺是300°C时效2h后炉冷，随后450°C时效7h炉冷，其硬度及导电率分别是HV205及18.2%IACS(国际退火铜标准)。

英文摘要：

The effects of Ni addition and aging treatment on the microstructure and properties of Cu?3Ti alloy were investigated. Themicrostructure and phase constituents were characterized by optical microscopy, scanning electron microscopy, X-ray diffractometerand high-resolution transmission electron microscopy, and the hardness and electrical conductivity were measured as well. Theresults show that NiTi phase forms with addition of Ni into as-cast Cu-3Ti alloy during solidification, and the as-cast microstructureevolves from dentrite to equiaxial structure. After aging treatment, coherent metastable β′-Cu4Ti precipitates from the Cu matrix.However, β′-Cu4Ti precipitation phase transforms into equilibrium, incoherent and lamellar Cu3Ti phase after overaging. Meanwhile,aging treatment results in appearance of annealing twins in the residual NiTi phase, and dislocation lines exist in the Cu matrix. Niaddition enhances the electrical conductivity, but decreases the hardness of Cu?3Ti alloy. In the range of experiments, the optimumaging treatment for Cu?3Ti?1Ni alloy is 300 °C for 2 h and 450 °C for 7 h. The hardness and electrical conductivity were HV 205and 18.2%IACS (international annealed copper standard), respectively.