Cu含量对Ni-Cu-P化学镀层组织结构和性能影响

Effect of Cu Content in Electroless Ni-Cu-P Coatings on Their Microstructure and Properties

利用化学镀法制备出Ni-Cu-P合金镀层,研究了镀液中CuSO4·5H2O含量对合金镀层沉积速率和成分的影响。通过XRD和SEM表征了不同CuSO4·5H2O质量浓度下Ni-Cu-P合金镀层的组织结构和表面形貌,运用极化曲线评价了合金镀层在质量分数为3.5%NaCl溶液中的耐蚀性能。结果表明,随着镀液中CuSO4·5H2O质量浓度的增加,镀层沉积速率和P含量不断下降,Ni-P镀层中P的质量分数为14.98%。当镀液中CuSO4·5H2O质量浓度为1.0 g/L时,P的质量分数为4.21%;镀层中Cu的含量随着镀液中CuSO4·5H2O含量的增加而增加。当添加量为1.0 g/L时,镀层中Cu的质量分数达19.04%;镀层的结晶度随着Cu含量的上升不断增大,Cu的加入使镀层的表面形貌更加光滑;镀层的耐蚀性能随着镀液中CuSO4·5H2O含量的增加先上升后下降,当镀液中CuSO4·5H2O质量浓度为0.4 g/L时,Ni-Cu-P镀层表现出最优的耐蚀性能。

Ni-Cu-P coatings were obtained by electroless plating.The effects of CuSO4·5H2O concentration in bath on the deposition rate and composition of Ni-Cu-P coatings were investigated.Microstructures and morphologies of Ni-Cu-P coatings obtained at various CuSO4·5H2O concentrations were analyzed via XRD and SEM.Corrosion resistances of Ni-Cu-P coatings were evaluated via polarization curves in 3.5% NaCl solution.The results show the deposition rate and P content of coatings decrease with the increasing of CuSO4·5H2O concentration in bath.P mass content in Ni-P coating was 14.98%.P mass content in coating was 4.21% when CuSO4·5H2O concentration in bath was 1.0 g/L.Crystallinity of coatings grows with the increasing of Cu content in electroless coatings.Addition of Cu in electroless bath makes the morphology of electroless coatings much smooth.Corrosion resistance of coatings first increased and then decreased with the increasing of CuSO4·5H2O concentration in bath.Ni-Cu-P coating obtained at 0.4 g/L CuSO4 concentration in bath performs optimal corrosion resistance.