Effect of high content of nickel and silicon on the microstructure and
properties of Cu-Ni-Si alloys
Abstract
Cu-Ni-Si alloys have been widely applied in electronic and electrical
industries.The effect of precipitation on the microstructure and
properties of the alloys are still not well understood. In this study,
Cu-Ni-Si alloys were prepared by hot-pressed sintering and elemental
copper powders, nickel powders and silicon powders as raw materials. The
results show that, there were no Ni-Si intermetallic compounds except
the δ-Ni2Si phase in the microstructure by hot-pressed sintered
preparation of Cu-Ni-Si alloys. And the distribution of the δ-Ni2Si
phase in the alloy was more uniform and smaller. After aging treatment,
when the mass ratio of Ni and Si were 2:1 and 3:1, the precipitation of
δ-Ni2Si phase was significantly less, and when the mass ratio of Ni and
Si were 4:1 and 5:1, the precipitation of δ-Ni2Si phase particles
increased significantly.The test results by electrical conductivity and
vickers hardness show that after ageing treatment, both the electrical
conductivity and vickers hardness of the alloys were greatly improved.
When the electrical conductivity was 39.33%IACS, the vickers hardness
was 230.95HV, and the Cu-Ni-Si alloy had the best comprehensive
performance.