镍钨合金电沉积的电流效率和镀层显微硬度

Current Efficiency and Deposit Microhardness of Nickel-Tungsten Alloy Electrodeposition

通过调节镀液中不同的 Ｎｉ／ Ｗ 比例、温度和沉积电流密度，研究在焦磷酸盐体系中镍钨合金电沉积的电流效率、沉积层组成和显微硬度。实验结果表明：合金共沉积的电流效率不高。为了尽量提高合金的沉积电流效率，主要途径宜增大镀液中硫酸镍和钨酸钠的浓度；提高合金沉积电流密度，降低镀液中［ Ｎｉ］／［ Ｗ］ 比例，则镀层中的钨含量增大；合金沉积层的显微硬度随镀层中的 Ｗ 含量提高而增大。

Current efficiency, deposit composition and microhardness of nickel-tungsten alloy electrodeposition in pyrophosphorus bath were studied by adjusting Ni/W ratio in plating solution, temperature and deposition current density. The results showed that the current efficiency of the alloy codeposition was not high. For the purpose to raise current efficiency as far as possible the suitable solution was to increase the concentration of nickel sulfate and sodium tungstate in the bath, Tungsten content in the alloy deposit can be increased by raising electrodeposition current density and decreasing [Ni]/[W] ratio in the plating solution. The microhardness of the alloy deposit increases with the raise of tungsten content in the deposit.