C/SiC材料表面Si/SiC涂层及其对基底结构的影响

采用泥浆预涂层反应法在C/ SiC 复合材料表面制备Si/ SiC 涂层。通过理论计算和实验确定了制备致密不开裂涂层的泥浆配比; 研究了埋粉烧结和气相硅真空反应烧结2 种不同烧结气氛对Si/ SiC 涂层微观形貌和成分的影响; 比较了单涂层和双涂层2 种不同涂层制备方法对C/ SiC 复合材料基底结构的影响; 用SEM 观察涂层形貌, 用XRD 分析涂层成分与晶体结构。结果表明: 泥浆中C∶Si (质量比) 在1∶1. 25 左右制备的涂层不开裂; 埋粉烧结制备的涂层成粉, 而气相硅真空反应烧结制备的涂层致密且与基底结合好; 单涂层法制备涂层后基底材料致密度高, 而双涂层法制备涂层后基底仍然保持多孔结构。 

Si/ SiC coatings on C/ SiC composites and their effects on the structure of the substrate

Si/ SiC coatings were prepared on C/ SiC composites by a slurry-precoating reaction process. The slurrycomponent s with which non-cracked coatings were prepared were concluded through theoretical calculation and experiment s. The effects of powder embedded sintering and vapor silicon vacuum-reaction-sintering atmosphere on themorphology and components of the Si/ SiC coatings were studied. The effect s of single-coating-process (SCP) anddouble-coating-process (DCP) on the st ructure of the subst rate were compared. The micrographs of the coatingswere observed by SEM. The component s and crystal st ructure of the coatings were analyzed by XRD. The result sshow that the non-cracked coatings prepared with slurry in which the mass ratio of C∶Si is 1∶1. 25 and the coatingsprepared by vapor silicon vacuum- reaction- sintering are dense and st rongly bonded with the subst rate , while thecoatings prepared by powder embedded sintering become powder. The st ructure of the subst rate becomes denserthan the coatings prepared by SCP , while the subst rate remaines porous af ter being coated by DCP.