高温合金电子束重熔硅化物涂层的抗氧化腐蚀性能

Oxidation Corrosion Resistance of Silicide Coating Remelted by Electron Beam on Superalloy

采用料浆烧结法在高温合金试样上喷涂硅化物涂层,随后对涂层进行了电子束重熔。对涂层分别进行了24 h的常温和1 800℃盐雾腐蚀试验,检测了涂层的表面和截面微观结构。结果表明:涂层由重熔层(外层)、主体层(中间层)和扩散层(内层)组成;重熔层呈柱状,耐蚀性较好;涂层表面粗糙度较小,并形成了连续均匀的玻璃状氧化物层,因此具有良好的抗氧化和耐腐蚀性能。

The silicide coating was sprayed on superalloy specimen by a slurry sintering process,then remelted by electron beam.The coating was subjected to salt spray test for 24 h at normal temperatures and 1800℃,respectively.The coating was tested for microstructure at both surface and cross-section.The results showed that(a)the coating consisted of remelt layer(outer layer),base layer(intermediate layer)and diffusion layer(inner layer);(b)the remelt layer was in columnar form,and possessed good corrosion resistance;and(c)the coating exhibited smaller surface roughness,and a glassy oxide layer formed on it,therefore the coating had good oxidation and corrosion resistances.