氧化时间对NiCoCrAlYTa涂层/镍基高温合金界面显微组织影响

Effect of Oxidation Duration on Interface Microstructure of NiCoCrAlYTa Coating on Nickel based Superalloy

采用真空等离子喷涂技术在DD407合金和DD6合金上制备了NiCoCrAlYTa涂层。通过SEM、EDS等方法研究了900℃不同氧化时间下经热处理后NiCoCrAlYTa涂层/DD407合金和NiCoCrAlYTa涂层/DD6合金的界面组织。结果表明,随着氧化时间延长,NiCoCrAlYTa涂层/DD407合金界面扩散层组织析出σ相,σ相形状发生明显变化,并且界面扩散层厚度缓慢增加,扩散系数为13.32μm/h;随着氧化时间延长,NiCoCrAlYTa涂层/DD6合金界面扩散层析出TCP相(σ相和μ相),TCP相形状未发生明显变化,并且界面扩散层厚度缓慢增加,扩散系数为3.85μm/h。

NiCoCrAlYTa coating was prepared on DD407 alloy and DD6 alloy by vacuum plasma spraying technology.At different oxidation duration,the microstructure of the interface of NiCoCrAlYTa coating/DD407 alloy and NiCoCrAlYTa coating/DD6 alloy in 900℃were studied by SEM、EDS and other methods.The results showed that with the increased of oxidation duration,σphase was precipitated at the interface of NiCoCrAlYTa coating/DD407 alloy,and the shape ofσphase changed significantly,the thickness of the interface diffusion layer increased slowly.The diffusion coefficient of the diffusion layer of was 1.051μm/h.While,with the increase of oxidation duration,TCP phases(σphase andμphase)was precipitated at the interface of NiCoCrAlYTa coating/DD6 alloy,and there was no significant changed about the shape,the thickness of the interface diffusion layer increased slowly and the diffusion coefficient of the diffusion layer was 1.15μm/h.