镁合金化学镀镍-磷镀速的影响因素及工艺优化

Factors Influencing Plating Rate of Electroless Ni-P Plating and Optimization of the Plating Process

通过系列对比试验,研究了AZ91D镁合金化学镀镍磷镀速的影响因素。结果表明,镀液配方、pH值和温度等对镀速会产生不同的影响,而镀速的大小不仅体现了生产效率的高低,更影响了镀层的结合力与性能。根据分析结果调整工艺配方及工艺参数,对镁合金化学镀工艺进行了相应的优化改进。该优化工艺可在镁合金表面得到均匀、致密、无明显缺陷的Ni-P镀层,镀层中镍的质量分数为91.44%,磷的为8.56%。性能测试表明,镀层的显微硬度为460～520HV,且具有良好的结合力。

A series of test was carried out to investigate the effects of various factors such as pH value,temperature,and concentration of 2NiCO3·3Ni(OH)2·4H2O,NaH2PO2·H2O,and H8C6O3·H2O on the plating rate of electroless nickel plating for AZ91D magnesium alloys.The optimized parameters were obtained by taking into account the effects of those factors and by modifying the plating bath composition and plating parameters as well.The results showed that the composition of the plating solution and its pH-value and temperature had complex influences on the plating rate.The plating rate was not only related to the production efficiency but also had effects on the adhesion strength and performance of the electroless Ni coating.It was feasible to prepare uniform and compact electroless Ni-P deposits without any visible defects using the optimized plating process.The resulting Ni-P alloy coating contained 8.56% P and had a hardness of 460-520 HV,while it was well adhered to the Mg alloy substrate.