镍-碳化钨纳米复合镀层的制备与性能

Preparation and properties of nickel-tungsten carbide nanocomposite coating

采用电镀的方法制备出Ni-WC纳米复合镀层,镀液组成为:NiSO4·7H2O250g/L,NiCl2·6H2O30g/L,H3BO330g/L,光亮剂0.1g/L,纳米WC颗粒5～30g/L,表面活性剂及分散剂适量。研究了温度、电流密度及pH对复合镀层外观的影响,得到最佳电镀工艺条件为:温度50～55°C,电流密度2～4A/dm2,pH4.5～5.0。在最佳工艺条件下制得的复合镀层,其显微硬度明显高于纯镍镀层和不锈钢,耐磨蚀性也优于不锈钢和纯镍镀层,耐腐蚀性优于不锈钢而劣于纯镍镀层。

A Ni-WC nanocomposite coating was prepared by electroplating. The composition of plating bath is as follows：NiSO4·7H2O 250 g/L,NiCl2·6H2O 30 g/L,H3BO3 30 g/L,brightener 0.1 g/L,WC nanoparticles 5-30 g/L,and suitable amount of surfactant and dispersant. The effects of temperature,pH and current density on the appearance of composite coating were studied. The optimal process parameters were given below：temperature 50-55 °C,pH 4.5-5.0,and current density 2-4 A/dm2. The composite coating prepared under the optimal process conditions has higher microhardness than pure nickel coating and stainless steel. The erosive abrasion resistance of the composite coating is better than that of stainless steel and pure nickel coating. The corrosion resistance of the composite coating was better than that of stainless steel but worse than that of pure nickel coating.