电弧喷涂Al,45CT及其复合涂层的抗高温氧化性能与机理

为获得抗氧化性能优良的涂层,采用电弧喷涂方法制备了Al,45CT及其复合涂层,探讨了3种涂层过渡层的形貌、物相及其相应的作用,分析了3种涂层的组织结构、抗氧化性能与机理。结果表明:Al涂层和复合涂层高温氧化后表面氧化膜有剥落现象,涂层中的抗氧化元素Cr含量很低;45CT涂层中的抗氧化元素Cr含量仍然很高,涂层的自我修复能力很强,表面生成的Cr2O3氧化膜具有优异的抗氧化性能;在涂层与基体结合处有一层过渡层,不仅增强了涂层与基体的结合力,还能进一步阻止氧化性气体向基体入侵,起到二次保护作用。

High-Temperature Oxidation Resistance and Anti-Oxidation Mechanism of Arc-Sprayed Al,45CT and Composite Coatings

Al coating,45CT coating and Al-45CT composite coating were prepared using arc spraying technology.The morphology,high-temperature oxidation resistance,anti-oxidation mechanism,as well as the microstructure and phase composition of the transition layers of the three kinds of arc-sprayed coatings were analyzed.It was found that the oxide films formed on Al coating and composite coating were peeled off after high-temperature oxidation,and the content of anti-oxidation element Cr was very low.Contrary to the above,arc-sprayed 45CT coating contained a high content of Cr and possessed strong self-repairing ability,while Cr2O3 layer on its surface showed excellent anti-oxidation ability.Moreover,a transition layer was formed at the coating-substrate interface,leading to enhanced adhesion between the coating and substrate and realization of secondary protection by preventing oxidizing gas from entering the substrate.