料浆烧结法制备改性Si-Cr-Fe高温抗氧化涂层的研究

采用料浆法在铌合金表面制备了Ge改性的Si—Cr-Fe系高温抗氧化涂层，分析了涂层氧化前后的表面和截面形貌、组织成分、相的分布等。将两次加涂后的涂层与一次加涂后的涂层形貌、组织和抗氧化性能进行了对比。结果表明：C-103铌合金表面的Si—Cr-Fe料浆熔烧涂层中，主体层是较致密的复杂硅化物相（Cr，Fe，Ge，Nb）Si2；扩散过渡层是致密的（Cr，Fe，Ge，Nb）5Si3相和少量（Cr，Fe，Ge，Nb）Si2的混合物；二次熔烧的涂层比加涂一次的涂层系统表面组织较均匀、致密，具有更宽的过渡层，对提高涂层的高温抗氧化性能有利；过渡层可有效阻止裂纹的进一步扩展，从而提高涂层的高温抗氧化性能。

Study of Modified Si-Cr-Fe High-temperature Anti-oxidation Coating by Fused Slurry Method

The high-temperature anti-oxidation Ge-added Si-Cr-Fe coating on the niobium alloy substrate is prepared by fused slurry method.The surface,section morphology,structure,component and phase distribution of the coating before and after oxidization is analyzed,and comparison is made between the morphology,structure and anti-oxidization property of 2-step coating and 1-step coating.The results indicate that the coating consists of tow layers.The out layer,the main body of the coating,is the complex phase of(Cr,Fe,Ge,Nb)Si_2.The inner layer which is a diffusion transition layer consists of the dense phases of(Cr,Fe,Ge,Nb)Si_2 and microdosis(Cr,Fe,Ge,Nb)_5Si_3.The interfaces among the body of coating,the diffusion transition layer and the substrate are smooth,dense with wider transition layer which can effectively stop the extension of cracks to improve high-temperature anti-oxidization property.