镍铁钨合金电沉积工艺

Process of Electrodeposited Nickel-Iron-Tungsten Alloy Coating

为获得性能良好的镍铁钨合金镀层,研究了电解液pH值、温度、电流密度、柠檬酸钠浓度对施镀阴极电流效率和镍铁钨合金镀层组分、表面形貌、显微硬度的影响。结果表明:镀液pH值对镀层形貌和阴极电流效率影响较大;随柠檬酸钠浓度增加,电流效率逐渐降低,镀层表面形貌更加粗糙。在镀液pH=8,温度70℃,电流密度7 A/dm2,柠檬酸钠浓度50 g/L时,阴极电流效率和镀层的显微硬度较高,表面光亮致密,耐蚀性好。

In order to obtain Ni-Fe-W alloy coatings with good properties,the effects of pH value,temperature,current density and concentration of sodium citrate on the cathodic current efficiency as well as composition,surface morphology and microhardness of the alloy coatings were studied.Results show that the pH value of electrolyte has a great impact on the coating morphology and cathodic current efficiency as well.The current efficiency decreased with increasing concentration of sodium citrate,while the surface of the alloy coatings became rougher therewith.A higher current efficiency was obtained at an electrolyte pH value of 8,temperature of 70 ℃,current density of 7 A/dm2 and sodium citrate concentration of 50 g/L,and corresponding Ni-Fe-W alloy coating was bright and dense and had a higher microhardness and better corrosion resistance.