稀土铈掺杂石墨烯对7050铝合金微弧氧化膜层结构与性能的影响

Microstructure and properties of rare earth CeO2-doped graphene composite coatings prepared by MAO on AA7050

采用微弧氧化(MAO)技术,以硅酸盐为主要电解液成分,通过加入稀土元素铈以及石墨烯添加剂,在7050高强铝合金表面制备微弧氧化膜层。利用扫描电镜(SEM)、体视显微镜、X射线衍射仪(XRD)、摩擦磨损试验机以及电化学工作站研究微弧氧化陶瓷膜层的形貌、粗糙度、相组成和元素分布以及耐磨性和耐蚀性。结果表明:同时加入4 g/L CeO2和10 g/L的石墨烯制备的复合膜层表面微孔尺寸明显降低,结构致密,耐磨性较好,粗糙度最低(1516.03 nm),膜层主要由α-Al2O3和γ-Al2O3组成。且此时的复合膜层自腐蚀电位最大,自腐蚀电流最小,耐腐蚀性最佳。

The ceramic coatings were prepared on the surface of 7050 high strength aluminum alloy by micro-arc oxidation process in a silicate electrolyte added with rare earth element cerium or graphene.The surface morphology,roughness,phase composition and distribution of elements,wear resistance and corrosion resistance were analyzed by the scanning electron microscope(SEM),surface profilometer,X-ray diffractometer(XRD),friction-abrasion tester,electrochemical workstation,respectively.The results show that the micro-pore size of the composite coatings which mainly consists ofα-Al2O3,γ-Al2O3 decreases and the compactness obviously improves with the simultaneous addition of 4 g/L CeO2 and 10 g/L graphene to the electrolyte.In addition,the roughness is the lowest(1516.03 nm)as well as the wear resistance is significantly improved.The corrosion is the best that the corrosion potential of the coating is the maximum and the corrosion current is the minimum.