Formation mechanism and oxidation behavior of MoSi_2-SiC protective coating prepared by chemical vapor infiltration/reaction  

化学气相浸渗/反应法制备MoSi_2-SiC涂层的合成机理及其氧化性能(英文)

作　　者：何子博[1] 李贺军[1] 史小红[1] 付前刚[1] 吴恒[1] 

机构地区：[1]西北工业大学 凝固技术国家重点实验室,西安710072

出　　处：《Transactions of Nonferrous Metals Society of China》2013年第7期2100-2106,共7页中国有色金属学报（英文版）

基　　金：Projects(51221001,51272213,51072166)supported by the National Natural Science Foundation of China;Project(GBKY1021)supported by the Fundamental Research Foundation of Northwestern Polytechnical University,China;Project(B08040)supported by Program of Introducing Talents of Discipline to Universities,China

摘　　要：In order to protect C/C composites from oxidation, SiC-MoSi2 composite coating was synthesized by chemical vapor infiltration /reaction （CVI/CVR） technology. A porous Mo layer was prefabricated on SiC coated C/C composites, and then MoSi2 and SiC were subsequently prepared in a CVI /CVR process using methyltrichlorosilane （MTS） as precursor. The deposition and reaction mechanism of the MoSi2-SiC composite coating was investigated by X-ray diffraction （XRD） and scanning electron microscopy （SEM）. The oxidation behavior of SiC-MoSi2 coated specimens was tested. The results show that the porous Mo layer can be densified with SiC phase decomposed from MTS, and transformed into SiC-MoSi2 by reacting with MTS as well. A dense composite coating was prepared with optimized deposition parameters. The coated specimen exhibits a good oxidation resistance with a little mass loss of 1.25% after oxidation at 1500 °C for 80 h.采用化学气相浸渗/反应法(CVI/CVR)在C/C复合材料表面制备MoSi2-SiC防氧化涂层。首先,制备多孔金属Mo层,然后以甲基三氯硅烷(MTS)为前驱体,利用CVI/CVR技术制备MoSi2-SiC复合涂层。采用XRD、SEM技术研究MoSi2-SiC复合涂层的制备机理,并考察涂层样品的抗氧化性能。结果表明,MTS分解的SiC填充了多孔金属Mo层中的孔隙,并与金属Mo发生反应,制备出致密的MoSi2-SiC复合涂层;在优化工艺条件下所得到的涂层样品在1500°C空气中氧化80h后质量损失仅为1.25%。

关 键 词：MoSi2-SiC coating deposition temperature initial partial pressure of MTS oxidation resistance 

分 类 号：TB332[一般工业技术—材料科学与工程] TB306