Mo-Si-B合金表面包埋渗Si-Al涂层的组织及氧化膜结构研究

Study on Microstructure and Oxidation Film Structure of Pack Si-Al Co-deposition Coating on Mo-Si-B Alloy Surface

采用包埋渗Si-Al的方法在Mo-9Si-8B(at%)合金表面制备抗氧化涂层,然后在1250℃下进行5 h氧化;同时制备包埋渗Si和Si-B涂层以进行对比。运用扫描电镜(SEM)和能谱仪(EDS)分析该涂层的组织和结构,利用X射线衍射仪(XRD)确定涂层的相组成,采用波谱仪(WDS)分析涂层中的B元素。结果表明:包埋渗Si和Si-B涂层都主要由MoSi_2外层和MoB内层组成,但Si-B共渗涂层内层更厚;Si-Al共渗在基体表面形成Al改性MoSi_2涂层,由Mo(Si,Al)_2外层和MoB内层组成。对三种涂层在1250℃下氧化5 h,前两种涂层表面氧化膜主要由SiO_2和Mo_8O_(23)组成,而Si-Al共渗涂层表面氧化膜主要由SiO_2、Al_2SiO_5和Mo_8O_(23)组成。

The anti-oxidation coating was prepared on the surface of Mo-9Si-8B(at%)alloy by pack cementation Si-Al and then oxidation at 1250℃for 5 h,and Si and Si-B coatings were prepared for comparison at the same time.The scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)were used to analyze the microstructure and structure of the coating,and X-ray diffractometer(XRD)was used to determine the constituent phase of the coating.B element in the coatings was determined by wave dispersive spectroscopy(WDS).The results show that Si deposition coating and Si-B co-deposition coating consist of MoSi2 outer layer and MoB inner layer,but the Si-B co-deposition coating has thicker inner layer;it forms Al-modified MoSi2 coating on the surface of the substrate by Si-Al co-deposition,which consists of Mo(Si,Al)2 outer layer and MoB inner layer.These three coatings are oxidized at 1250℃for 5 h,the oxidation film on the first two coatings is mainly composed of SiO2 and Mo8O23,while the oxidation film on the Si-Al co-deposition coating is mainly composed of SiO2,Al2SiO5 and Mo8O23.