石墨烯添加剂对铝合金表面微弧氧化膜耐磨耐蚀性的影响

Influence of graphene additive on wear resistance and corrosion resistance of micro arc oxidation coating formed on LY12 aluminium alloy surface

利用微弧氧化技术,通过在硅酸盐电解液中加入石墨烯添加剂,在LY12铝合金表面制备一层含碳陶瓷层,采用扫描电镜、X射线衍射仪和电化学工作站等对陶瓷层的微观结构、成分组成以及耐磨耐蚀性能进行分析检测。结果表明:制备的含碳陶瓷层表面微孔尺寸和粗糙度值均明显降低,主要由Al_2O_3、SiO_2以及Al_2SiO_5物相组成。相比于不含碳的陶瓷层,含碳陶瓷层最大厚度为20.5μm,而且更加均匀致密。在相同的摩擦条件下,含碳陶瓷层的摩擦系数仅为0.09,比不含碳陶瓷层摩擦系数值降低了近3倍,表现出良好的减摩性能。由于含碳陶瓷层的厚度和致密性提高,使其腐蚀电流密度显著降低,耐蚀性也得到了明显的改善。

Carbon-containing ceramic coating was prepared on the surface of LY12 Al alloy by micro-arc oxidation（MAO） process in a silicate electrolyte added with graphene powders（GE）,and microstructure,composition,tribological and corrosion behaviors of the coating were analyzed by means of scanning electron microscopy,X-ray diffraction and electrochemical workstation.The results show that the micro-pore size and surface roughness of the ceramic coating,which mainly consists of Al2O3,SiO2 and Al2SiO5 phases,decrease significantly.Compared with the carbon-free ceramic coating,the carbon-containing ceramic coating with maximum thickness of 20.5 μm is more compact and uniform.Under the same friction condition,the friction coefficient of the carbon-containing ceramic coating is only 0.09,which is nearly 3 times lower than that of the carbon-free ceramic coating,exhibits good antifriction property.Due to the increase of the thickness and the compactness of the carbon-containing ceramic coating,its corrosion current density is significantly reduced,and the corrosion resistance is improved obviously.