化学镀Ni-W-P镀液及工艺优化研究

采用正交试验，以镀层的耐硝酸变色时间为评价标准，得到化学镀Ni—W—P溶液最佳配方为：20g／L硫酸镍、20g／L钨酸钠、20g／L次磷酸钠、40g／L络合剂、20g／L缓冲剂、pH值为60对该优化镀层的沉积速度、耐蚀性、孔隙率及结合力进行了测定，并与Ni—P二元合金镀层进行了比较。结果表明，该优化镀层的性能优于Ni—P二元合金。采用扫描电镜及X-射线衍射仪分别对该优化镀层的微观形貌、组成及结构进行的分析表明，该镀层结构致密，磷含量高达13.9％，且为非晶态结构。

Optimization of electroless Ni-W-P plating process

By an orthogonal test and with the tarnish time of resistance to nitric acid as evaluation criterion, the optimal formula of electroless Ni-W-P plating bath was obtained as follows: 20 g/ L of nickel sulfate, 20 g/ L of sodium tungstate, 20 g/L of sodium hypophosphite, 40 g/L of complexant, 20 g/L of buffering agent and pH value of 6. The deposition rate, corrosion reistance, porosity and adhesion of the coatings deposited from the optimal bath were determined and compared with those of Ni-P alloy deposits. The results show that the properties of the optimized coatings are superior to those of Ni-P alloy coatings. The SEM and XRD analysis on the micro-morphology, composition and structure of the optimized deposits demonstrates that the optimized Ni-W-P alloy coatings have dense and amorphous structure and 13.9% of phosphorus by weight.