In the current investigation, various mass fractions (0, 0.5, 1.5, 5 and 10 wt%) of Ni were doped into Cu substrate, and influences of Ni addition on the microstructure evolution and mechanical property of the Sn–58Bi/Cu–xNi solder joint were investigated. Results showed that the growth rate of intermetallic compound (IMC) would increase with the Ni addition added from 0 to 5 wt% and remarkably decreased for Sn–58Bi/Cu–10Ni joint system. It indicated that the growth rate of IMC layer would decrease when 10 wt% Ni was added into the alloy. Besides, the tensile strength reduced with increase in the IMC thickness, which was under the synergistic effect of increasing liquid-state reaction time and the content of Ni addition (0–5 wt%). Moreover, the fracture mechanism gradually transformed from ductile fracture mode to brittle fracture mode with the decrease in joint strength.

中文翻译：

---

Cu– x Ni合金中添加Ni对Sn–58Bi / Cu– x Ni焊点的组织演变和力学性能的影响

在当前的研究中，将各种质量分数（0、0.5、1.5、5和10 wt％）的Ni掺杂到Cu基体中，并且添加Ni对Sn–58Bi / Cu– x的组织演变和力学性能的影响镍焊点进行了调查。结果表明，金属间化合物（IMC）的生长速率会随着Ni的添加从0到5 wt％的增加而增加，而对于Sn–58Bi / Cu-10Ni接头体系，则显着下降。结果表明，在合金中添加10wt％的Ni，IMC层的生长速率会降低。此外，抗拉强度随IMC厚度的增加而降低，这是由于增加了液相反应时间和添加Ni的含量（0-5 wt％）的协同作用。此外，随着接头强度的降低，断裂机理逐渐从韧性断裂方式转变为脆性断裂方式。