纳米TiO_2添加剂对ZL101A铝合金微弧氧化膜耐蚀性能的影响

目前,关于纳米TiO_2含量对铝合金微弧氧化膜耐蚀性的影响报道较少。在硅酸盐电解液中加入不同浓度纳米TiO_2,在ZL101A铝合金表面制备微弧氧化膜。采用扫描电镜(SEM)、X射线衍射仪(XRD)、电化学极化曲线及交流阻抗等,研究了纳米TiO_2浓度对微弧氧化膜耐蚀性能的影响。结果表明:纳米TiO_2进入到微弧氧化膜中,膜层表面变得更加致密;随着纳米TiO_2浓度的增加,膜层在3.5%Na Cl溶液中的腐蚀电流密度不断减小,交流阻抗不断增大,膜层的耐蚀性明显提高;综合考虑形貌和耐蚀性,本工作中纳米TiO_2最佳浓度为20 g/L。

Effects of Nano-Additive TiO2 on Corrosion Resistance of Micro-Arc Oxidation Ceramic Coatings Formed on ZL101A Aluminum Alloy

TiO2-containing ceramic coatings were prepared on ZL101A aluminum alloy substrates by micro-arc oxidation (MAO) in silicate electrolytes doped with different concentrations of nano-TiO2.The effects of nano-additive concentration on corrosion resistance were investigated by means of SEM,XRD and electrochemical workstation.Results showed that nano-particles were incorporated into the resulting coating during the MAO process,and the ceramic coatings became more compact.Besides,with the increase of TiO2 concentration in the electrolyte,the corrosion current density was decreased and the alternating current impedance was increased,indicating that the corrosion resistance of coatings was increased consequently.Furthermore,the optimized concentration of TiO2 in the electrolyte was 20 g/L.