NiCo/纳米SiO2复合镀层的耐腐蚀及其摩擦学性能研究

采用电沉积法在铜基底上沉积了NiCo/纳米SiO2复合镀层和NiCo合金镀层,用扫描电子显微镜、CHI660A电化学工作站及UMT-2M摩擦磨损测试机考查了镀层的表面形貌、磨损形貌、耐腐蚀性能及摩擦学性能.结果表明,纳米SiO2颗粒的加入抑制了NiCo晶体的增长,使得镀层中NiCo颗粒明显得到细化,镀层更加均匀致密;在相同的腐蚀和摩擦条件下,纳米复合镀层的耐蚀性、耐磨性能明显高于NiCo合金镀层;随着镀液中纳米颗粒悬浮量的增加,复合镀层的摩擦系数先降低后增大,当镀液中SiO2纳米颗粒含量为5 g/L时复合镀层的摩擦系数最小.

Research on corrosion resistance and tribological properties of NiCo/nano-SiO2 composite coatings

NiCo/nano-SiO2 composite coating and NiCo alloy coating are electro-deposited on copper substrate.Scanning electron microscope(SEM) is used to observe the morphology of the sample.The CHI660A electrochemistry station is used to study the polarization curve and AC impedance in 0.5 mol/L NaCl solution.The UMT-2M wear tester system is used to measure the wear properties and the influence for the different concentrations of nano-SiO2 particulates in the plating bath on the friction coefficient.The results show that the addition of SiO2 nanoparticles to the plating solution refrains from the growth of NiCo crystals and makes the coating better-distributed and more-compact than that without SiO2 nanoparticles.At the same corrosion and tribological conditions,the NiCo/SiO2 nanocomposite coating has better corrosion resistance and tribological property than NiCo alloy coating.The concentrations of SiO2 particles in the plating bath have a remarkable effect on the friction coefficient of the nanocomposite coating.With the addition of nanoparticles in the plating bath,the friction coefficients of the composite coating become small firstly,then become big.When the concentration of nano-SiO2 in the plating bath is 5g/L,the friction coefficient is the lowest.