Ti62421s钛合金基体/离子镀CrN涂层的微观表征与高温氧化行为

Charaterization and high-temperature oxidation behavior of arc-ion-plating CrN coating on Ti62421s alloy

采用电弧离子镀（AIP）技术在Ti62421s钛合金基体表面沉积CrN涂层。测定了Ti62421s钛合金和CrN涂层/钛合金基体试样在700-900℃氧化时的动力学曲线,进而通过扫描电镜（SEM）、能谱（EDS）分析与X射线衍射分析（XRD）研究Ti62421s钛合金及CrN涂层/钛合金界面在800℃及900℃氧化前后的显微组织和物相组成。结果表明：在700-900℃静态空气中氧化200h过程中,CrN涂层对钛合金基体有很好的保护作用。在800℃和900℃静态空气中氧化200 h后,Ti62421s钛合金表面形成TiO2、Al2O3氧化膜。CrN涂层/钛合金基体试样在800℃氧化200 h后,CrN涂层表面生成片层状Cr2O3膜;在900℃氧化200 h后,涂层中发生CrN向Cr2N的相转变,涂层的抗氧化能力降低。800℃和900℃分别氧化200 h后,CrN涂层/钛合金基体界面处形成Ti2N相。

CrN coating was deposited on Ti62421s alloy by arc ion plating（AIP）.The oxidation kinetic curves of Ti62421s alloy and CrN coating were obtained.The microstructure and morphology of the Ti62421s alloy and CrN coating before and after oxidation at 800℃and 900℃ were analyzed by SEM,EDS and XRD.The results show that CrN coating can effectively protect the substrate Ti62421s alloy at 700~900℃ for 200 h.At 800℃ and 900℃ for 200 h,the oxidation film of TiO2 and Al2O3 was formed on the surface of Ti62421s alloy.At 800℃ for 200 h the laminated Cr2O3 film was formed on the surface of the CrN coating.At 900℃ for 200 h,CrN changes into Cr2N and the oxidation-resistance of the coating was lowered.At 800℃ and 900℃ for 200 h,a new phase of Ti2N formed at the alloy/coating interface.