纳米Cr颗粒对Ni-Mo复合镀层性能的影响

为了研究纳米Cr颗粒对Ni-Mo复合镀层性能的影响,采用脉冲电沉积方法制备具有不同Cr含量的Ni-Mo复合镀层.利用扫描电子显微镜和X射线衍射仪分别观察和分析复合镀层的组织形貌及结构.采用电化学测试和X射线光电子能谱研究复合镀层的析氢性能和耐蚀性能.结果表明:随着镀液中纳米Cr颗粒含量的增加,镀层晶粒得到细化,析氢过电位增大,复合镀层析氢性能得到提高;当镀液中纳米Cr颗粒含量为20 g/L时,复合镀层表面钝化膜中MoO₃含量较高,且可与Cr产生协同效应,因而复合镀层具有较好的耐蚀性能;但随着镀液中纳米Cr颗粒含量的进一步增加,复合镀层中沉积的Cr元素含量降低,复合镀层的析氢性能和耐蚀性能均降低.因此,当镀液中纳米Cr颗粒含量为20 g/L时,复合镀层具有较好的析氢性能和耐蚀性能.

Effect of Cr nanoparticles on properties of Ni-Mo composite coatings

In order to investigate the effect of Cr nanoparticles on the properties of Ni-Mo composite coatings, the Ni-Mo composite coatings with different Cr contents were prepared by a pulse electroplating method. The morphology and microstructure of composite coatings were observed and analyzed with scanning electron microscope(SEM)and X ray diffractometer. The hydrogen evolution performance and corrosion resistance of coatings were carried out through electrochemical tests and X ray photoelectron spectroscopy. The results show that with the increase of Cr nanoparticle content in the plating solution, the grain size of coating can be refined, the hydrogen evolution over-potentials increase, and the hydrogen evolution performance of composite coatings gets improved. When the Cr nanoparticle content in the plating solution reaches 20 g/L, the MoO₃ content in the passive film on composite coating surface is higher and can motivate synergistic effect with Cr, so the corrosion resistance of composite coating becomes better. However, when adding more Cr nanoparticles, the deposited Cr content in coatings becomes lower, so the hydrogen evolution performance and corrosion resistance of composite coatings get worse. Therefore, the composite coating has better hydrogen evolution performance and corrosion resistance when Cr nanoparticle content is 20 g/L.