电沉积铁镍钨合金性能研究

Study of the Properties of Electrodeposited Fe-Ni-W Alloy Coating

钨合金沉积机理至今未得到合理的解释。采用循环伏安法研究了柠檬酸铵盐体系中电沉积铁镍钨合金的规律,分析了主盐浓度、pH值、电流密度、温度对铁镍钨合金镀层组分及阴极电流效率的影响。结果表明,在pH值恒定为8的条件下,镀层中钨和铁的含量受各因素影响的趋势是一致的,随溶液中铁盐、钨盐、柠檬酸盐的含量、电流密度及温度的增加而增加;镀层组分受pH值的影响较大,镀层中钨含量值在pH值为6时最大。根据X射线衍射结果可知,铁镍钨镀层随着钨含量的增加,由纳米结构转变为非晶态结构。

The process for electrodepositon of Fe-Ni-W alloy coating on steel substrates from an ammonia citrate bath was investigated using cyclic voltammetry. Thus the effects of the concentration of electrolyte, pH value, current density and temperature on the composition of the coating and cathodic current efficiency were investigated. And the optimum technology for electroplating of Fe-Ni-W nanocrystalline alloy was established. Results indicated that the tungsten content in the alloy deposit was in a range of 0-30% , depending on the operating condition and it increased with increasing ratio of iron to nickel, concentration of citrate, cathode current density, and temperature. The composition of the alloy coating was greatly influenced by the pH value of the bath, and the maximum tungsten content was reached at a pH value of 6. Moreover, the structure of the Fe-Ni-W coating gradually changed from nanocrystalline phase to amorphous phase with increasing tungsten content.