(1. 常州大学 材料科学与工程学院，常州 213164；
2. 常州大学 江苏省材料表面科学与技术重点实验室，常州 213164；
3. 常州大学 机械工程学院，常州 213164)
摘 要: 采用激光熔覆与微弧氧化技术相结合在S355海洋钢表面制备了复合陶瓷膜层，运用扫描电子显微镜(SEM)、能谱仪(EDS)和X射线衍射仪(XRD)表征陶瓷膜层的微观结构，通过涂层结合力、显微硬度、残余应力、摩擦磨损和电化学等测试方法研究复合膜层的性能。结果表明：复合陶瓷膜层主要由内致密层和外疏松层组成，疏松层主要由γ-Al2O3组成，致密层主要由α-Al2O3组成。随着电流密度增大，膜层厚度与微孔孔径逐渐增大。复合膜层与基底层结合良好，其硬度较熔覆涂层的有明显提升。熔覆涂层表面残余应力为拉应力，复合膜层均为压应力。在电流密度为5 A/dm2时，复合膜层能明显改善基体与熔覆涂层的耐磨性与耐蚀性。
关键字: S355海洋钢；激光熔覆；微弧氧化；复合陶瓷膜层；显微组织
（1. School of Materials Science and Engineering, Changzhou University, Changzhou 213164, China;
2.Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164, China;
3. School of Mechanical Engineering, Changzhou University, Changzhou 213164, China）
Abstract:The composite ceramic films were prepared on the surface of S355 offshore steel by laser cladding combined with micro-arc oxidation technology, and the composite films structures were evaluated by SEM, EDS and XRD. The properties of the composite coatings were studied by a coating scratch tester, microhardness tester, X-ray stress measurement instrument, friction and wear test machine and electrochemical workstation. The results show that the composite ceramic film is mainly composed of an inner dense layer and an outer loose layer, the loose layer is mainly composed of γ-Al2O3, and the dense layer is mainly composed of α-Al2O3. With the increase of current density, the film thickness and the micropore diameter gradually increase. The composite film is well integrated with the substrate layer. Compared with cladding coating, the hardness of composite films is improved significantly. The residual stress on the surface of the cladding coating is tensile stress, and the residual stress of the composite film is compressive stress. When the current density is 5 A/dm2, the composite film can significantly improve the wear resistance and corrosion resistance of the substrate and the cladding layer.
Key words: S355 offshore steel; laser cladding; micro-arc oxidation; composite ceramic films; microstructure
