化学沉积Ni—Cu—P合金镀层的组织结构

利用DSC和XRD研究了化学沉积Ni-Cu-P合金镀层的组织结构和晶化过程。结果表明：随着镀层中Cu含量的升高，Ni-Cu-P合金镀层向亚稳中间相Ni5P2及Ni12P5转变和亚稳中间相Ni5P2及Ni12P5向热力学稳定的Ni3P相转变的温度均逐渐升高；非晶态结构的合金镀层（质量分数）Ni-8.47%Cu-15.39%P、Ni-15.35%Cu-13.90%P及Ni-19.71%Cu-12.83%P在300℃加热后仍保持非晶态，而在363.39℃、363.69℃及370.04℃，这3种合金镀层分别转变为亚稳中间相Ni5P2及Ni12P5，随着温度的升高在428.20℃、442.54℃及453.96℃，合金镀层中的亚稳中间相Ni5P2及Ni12P5又进而转变为稳定相Ni3P；对于晶态结构（质量分数）Ni-56.49%Cu-6.01%P合金镀层，在170-330℃，镀层中Ni-Cu晶粒粗化、磷元素向晶界偏聚，在397.80℃镀层中的非晶相转变为亚稳中间相Ni5P2，在464.89℃亚稳中间相Ni5P2转变为稳定相Ni3P。

Microstructure of Electroless Ni-Cu-P Deposits

Microstructures of electroless Ni-Cu-P deposition were studied by using DSC and XRD. The results show that both the temperatures of Ni-Cu-P depsoits transforming to metastable phases Ni5P2 and Ni12P5, and metastable phases Ni5P2 and Ni12P5 transforming to thermodynamics equilibrium phase Ni3P increase gradually; the amorphous Ni-8.47％Cu-15. 39％P, Ni-15. 35％Cu-13. 90％P and Ni-19. 71％Cu12.83％P deposits still remain to be amorphous after heated at 300℃; while at 363.39℃, 363.69℃ and 370.04℃, the amorphous deposits transform to the metastable phase Ni5P2 and Ni12P5 respectively; as the temperatures increase, at 428.20℃, 442.54℃ and 453.96℃, the metastable phases Ni5P2 and Ni12P5 in the deposits ulteriorly transform to the stable phases Ni3P; for the crystal Ni-56.49％Cu-6.01％P deposit, Ni-Cu grains grow and P segregates to the grain boundaries at 170～330℃, at 397.80℃ the amorphous phases in the deposits transform to the metastable phases Ni5P2; the metastable phases Ni5P2 transform to the stable phase Ni3P at 464.89℃.