WC/Co含量对Ni-WC/Co纳米复合镀层腐蚀性能的影响

Effect of WC/Co Content on Corrosion Behavior of Nanocomposite Coatings of Ni-WC/Co

采用脉冲电沉积制备出Ni-WC/Co纳米复合镀层,研究镀液中WC/Co含量对复合镀层晶体结构、晶粒尺寸和硬度的影响;室温下,通过测试复合镀层在3.5%(质量分数)NaCl溶液中的电化学行为,分析镀层的耐蚀性能。结果表明:随着镀液中WC/Co含量增加,复合镀层平均晶粒尺寸先减小后增大,硬度则是先增大后减小,复合镀层的耐蚀性能是先升高后降低。当WC/Co含量为30 g/L时,复合镀层的平均晶粒尺寸最小,硬度最高,腐蚀电位(E_(corr))较高,腐蚀电流密度(I_(corr))最低,耐蚀性能最佳。

Nanocomposite coatings of Ni-WC/Co were prepared by pulsed electrodeposition. The effect of WC/Co content on the crystallographic structure, grain size and hardness, as well as the electrochemical corrosion behavior in 3.5%（mass fraction） NaCl solution of the coatings were investigated. Results show that with the increase of WC/Co content in the plating bath in a range of 0～50 g/mol, the average grain size of the composite coatings decreases first and then increases, while their hardness and corrosion resistance increases first and then decreases respectively. Among others, the prepared coating with the bath containing 30 g/L WC/Co, showed the smallest average grain size, the highest hardness and the best corrosion resistance.