Abstract

Microstructure of Cu–Ni–Si alloys, especially morphology, amount and size of Ni–Si intermetallics, was controlled by heat and thermal–mechanical treatment, and then its influence on electrical breakdown behavior was investigated systematically. Results show that first breakdown is prior to occur on the Ni₃Si phase at the grain boundary and δ-Ni₂Si in the inner of Cu matrix in Cu–Ni–Si alloys. The decrease of Ni₃Si size by using thermal–mechanical treatment can significant enhance the breakdown behavior of Cu–Ni–Si alloys since it can change the total area of preferred phase within the action area of cathode spot. As a result, the chopping current and erosion depth decrease but arc life, breakdown field and erosion area increase with the decrease of Ni₃Si size, while the precipitation δ-Ni₂Si phase has limited effect on breakdown properties. On the whole, Cu–Ni–Si alloy by solution, hot forging and aging treatments in sequence has the best breakdown properties due to the uniform dispersion of Ni₃Si phase.

中文翻译：

---

Cu-Ni-Si合金中Ni-Si金属间化合物的调控及其对电击穿性能的影响

摘要

通过加热和热机械处理来控制Cu-Ni-Si合金的微观结构，尤其是Ni-Si金属间化合物的形态，数量和大小，然后系统地研究其对电击穿行为的影响。结果表明，在Ni发生第一击穿是现有₃在晶界和δ-Ni系Si相₂在内部中的Cu-Ni-Si系合金的Cu基质的硅。通过热机械处理减小Ni ₃ Si尺寸可以显着增强Cu-Ni-Si合金的击穿性能，因为它可以改变阴极点作用区域内优选相的总面积。结果，随着Ni的减少，斩波电流和腐蚀深度减小，但是电弧寿命，击穿场和腐蚀面积增加₃的Si的大小，而沉淀δ-Ni系₂ Si相对击穿性能的影响有限。总体而言，由于Ni ₃ Si相的均匀分散，依次进行固溶，热锻和时效处理的Cu-Ni-Si合金具有最佳的击穿性能。