(1. 常州大學 材料科學與工程學院，常州 213164；
2. 常州大學 江蘇省材料表面科學與技術(shù)重點實驗室，常州 213164；
3. 常州大學 機械工程學院，常州 213164)
摘 要: 采用激光熔覆與微弧氧化技術(shù)相結(jié)合在S355海洋鋼表面制備了復合陶瓷膜層，運用掃描電子顯微鏡(SEM)、能譜儀(EDS)和X射線衍射儀(XRD)表征陶瓷膜層的微觀結(jié)構(gòu)，通過涂層結(jié)合力、顯微硬度、殘余應(yīng)力、摩擦磨損和電化學等測試方法研究復合膜層的性能。結(jié)果表明：復合陶瓷膜層主要由內(nèi)致密層和外疏松層組成，疏松層主要由γ-Al2O3組成，致密層主要由α-Al2O3組成。隨著電流密度增大，膜層厚度與微孔孔徑逐漸增大。復合膜層與基底層結(jié)合良好，其硬度較熔覆涂層的有明顯提升。熔覆涂層表面殘余應(yīng)力為拉應(yīng)力，復合膜層均為壓應(yīng)力。在電流密度為5 A/dm2時，復合膜層能明顯改善基體與熔覆涂層的耐磨性與耐蝕性。
關(guān)鍵字: S355海洋鋼；激光熔覆；微弧氧化；復合陶瓷膜層；顯微組織
（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
