SiC含量对内燃机用Ti-6Al-4V合金复合膜组织和摩擦性能的影响

Effects of SiC content on the composite membrane structure and friction properties of Ti-6Al-4V alloy for internal combustion engine

通过在微弧氧化电解液中加入SiC微粒的方式制备内燃机用Ti-6Al-4V合金复合膜,采用扫描电子显微镜和摩擦磨损实验测试分析SiC质量浓度对复合膜组织和摩擦性能的影响。研究结果表明:没有加入SiC时,膜层表面形成许多微孔;在SiC含量低于5.0 g/L时,膜层表面形成了均匀微孔结构;随SiC含量增大至7.5 g/L,膜层孔洞数量减少。膜层和Ti-6Al-4V合金基体间形成了良好的界面结合,几乎没有裂纹生成,并且在膜层的界面区域生成部分孔洞结构。随SiC含量增大,膜层厚度减小,摩擦因数先降低后升高,且在Ti-6Al-4V合金基体中形成了许多宽度与深度都较大的沟槽,磨损机理为磨粒磨损。

Ti-6Al-4V alloy composite membrane for internal combustion engine was prepared by adding SiC particles into micro arc oxidation electrolyte.The microstructure and friction properties of the composite film were studied by SEM and friction-wear test.The results show that many net micropores form on the surface of the sample without SiC.When the SiC content is lower than 5.0 g/L,uniform microporous structure forms on the membrane surface.With the increase of SiC content to 7.5 g/L,the number of pores in the membrane layer decreases.The membrane layer and the substrate of Ti-6Al-4V alloy is bonded well and almost no crack is found.Moreover,partial pore structure forms in the interface area of the membrane layer.The film thickness decreases with the increase of SiC content.The friction coefficient decreases first and then increases with increasing SiC content,many grooves with larger width and depth form in the alloy matrix.The wear mechanism is abrasive wear.