钢铁全光亮化学镀镍–钨–磷合金工艺研究

Study on fully bright electroless Ni–W–P alloy plating process on iron and steel

为了提高Ni–P合金镀层的耐蚀性和表观质量,在化学镀Ni–P二元合金镀液的基础上加入钨酸钠,在钢铁上制备了Ni–W–P三元合金镀层。探讨了镀液主要成分和工艺条件对镀层外观质量及耐蚀性的影响,获得了较佳的工艺规范：硫酸镍25~35 g/L,钨酸钠55~65 g/L,次磷酸钠30~40 g/L,复合配位剂80~100 g/L,组合光亮剂5~10 mg/L,p H 8.5~9.0,温度80~90℃。检测了镀层的相关性能。结果表明,所制备的Ni–W–P合金镀层结晶细致,光亮度和结合力好,具有良好的装饰效果,耐蚀性优于化学镀Ni–P合金镀层。

To improve the corrosion resistance and appearance quality of Ni-P alloy deposit, sodium tungstate was added to the electroless Ni-P binary alloy plating bath to prepare an Ni-W-P ternary alloy deposit on iron and steels. The effects of the main components in bath and process specifications on the appearance quality and corrosion resistance of deposit were studied. The optimal conditions were determined as follows： NiSO4·7H2O 25-35 g/L, Na2WO4·2H2O 55-65 g/L, Na2HPO2·H2O 30-40 g/L, composite complexing agent 80-100 g/L, composite brightener 5-10 rag/L, pH 8.5-9.0, and temperature 85-90 ℃. The relevant properties of deposit were tested. The results indicated that the Ni-W-P alloy deposit prepared is fine-grained, very bright, decorative with good adhesion strength and better corrosion resistance as compared with the electroless Ni-P alloy deposit.