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采用料浆烧结法在钼合金表面制备Mo Si2-Zr B2高温抗氧化涂层,并进行1 670℃静态氧化试验,利用电子探针显微分析仪(EPMA)、扫描电镜(SEM)、能谱分析(EDS)、X线衍射仪(XRD)等对涂层氧化前后的形貌与组织结构进行观察和研究,同时分析了涂层高温防护机制及失效机制。结果表明:涂层为复合多相结构,在高温氧化环境下,涂层表面会形成熔融态的非晶玻璃膜,可有效阻碍氧气向试样内部的进一步扩散,从而提高材料的抗氧化性能;通过静态抗氧化实验证实涂层具有良好的抗氧化性能,在1 670℃下静态抗氧化寿命可达12 h;涂层失效主要包括纵向裂纹萌生贯通至基体和横向裂纹扩展与基体剥离两种失效方式。
The Mo Si2-Zr B2 high-temperature oxidation-resistant coating was prepared on the surface of molybdenum alloy by slurry sintering method. The static oxidation at 1670 ℃ was carried out. The microstructure of the Mo alloy was characterized by means of electron probe microanalyzer (EPMA), scanning electron microscope (EDS) and X-ray diffraction (XRD) were used to observe and study the morphology and microstructure of the coating before and after oxidation. At the same time, the protective mechanism and failure mechanism of the coating were analyzed. The results show that the coating is a composite multiphase structure. Under the high temperature oxidation environment, the amorphous glass film is formed on the surface of the coating, which can hinder the further diffusion of oxygen into the sample and improve the oxidation resistance of the material. Static anti-oxidation experiments show that the coating has good anti-oxidation properties, and the static antioxidant life at 1 670 ℃ is up to 12 h. The failure of coatings mainly includes longitudinal crack initiation through the matrix and transverse crack propagation and matrix delamination the way.