Ti_3SiC_2表面渗硅涂层的抗高温氧化性能  

Oxidation performances of silicide coatings on Ti_3SiC_2-based ceramic

作　　者：刘光明[1] 李美栓[1] 张亚明[1] 周延春[1] 

机构地区：[1]中国科学院金属研究所沈阳材料科学国家(联合)实验室,沈阳110016

出　　处：《中国有色金属学报》2002年第4期629-633,共5页The Chinese Journal of Nonferrous Metals

摘　　要：采用固体粉末包埋法在Ti3 SiC2 陶瓷上渗硅 ,研究了渗硅涂层的抗高温氧化性能 ,用XRD及SEM /EDS分析了渗硅涂层及其氧化后产物的成分、结构和形貌等。结果表明 :渗硅层主要由TiSi2 和SiC组成 ,在空气中氧化时形成了SiO2 和TiO2 的混合氧化物膜。渗硅样品在 110 0℃和 12 0 0℃下的恒温氧化速率比Ti3 SiC2 降低了 2～3个数量级 ,110 0℃下抗循环氧化性能也优于Ti3 SiC2 。但由于渗硅层中存在裂纹 ,循环过程中当裂纹贯穿整个渗硅层时 ,涂层的氧化速度开始增加 ,其保护作用逐步退化。在 110 0℃下空气中循环氧化时 ,经 40 0次循环后涂层已基本失效。Silicide coating was prepared on Ti 3SiC 2 base ceramic by pack cementation. The microstructure, phases and oxidation resistance of the coating were investigated. The results show that, the silicide coating is mainly composed of TiSi 2 and SiC; one layer of the mixture of SiO 2 and TiO 2 is formed when the coating is oxidized. At 1?100?℃ and 1?200?℃, the oxidation rate of silicide coating is 2～3 order lower than that of Ti 3SiC 2. The cyclic oxidation resistance of the coating is much higher than that of Ti 3SiC 2. There are a great number of fine cracks in the outer layer of the coating. When these cracks penetrate whole coating during the cyclic oxidation, the oxidation rate begins to increase, which is the main reason for the loss of the protection of coating.

关 键 词：钛碳化硅 渗硅 高温氧化 涂层 

分 类 号：TG174.4[金属学及工艺—金属表面处理] TG172.82[金属学及工艺—金属学]