包埋／溶胶凝胶两步法制备碳／碳复合材料表面抗氧化涂层  

Oxidation Protective Coating on Carbon/Carbon Composite Prepared by Two-step Processes of Pack Cementation and Sol-gel

作　　者：许志俊[1] 迟伟东[1] 刘辉[1] 于建民[1] 杨旭堃[1] 

机构地区：[1]北京化工大学碳纤维及功能高分子教育部重点实验室,北京100029

出　　处：《热加工工艺》2012年第20期107-110,共4页Hot Working Technology

摘　　要：采用结合包埋法和溶胶凝胶法(sol-gel)在碳/碳(C/C)复合材料表面制备了SiC-SiC/TaC涂层,借助扫描电镜、X射线衍射等手段对涂层的微观组织形貌和物相组成进行观察与分析。结果表明:该包埋工艺中SiC为晶须状生长形成具有晶须增韧的涂层,且溶胶-凝胶法制备的外涂层致密有效的填充了SiC晶须间空隙并完全覆盖,涂层厚度由4μm增加至8μm,从而具备良好的防氧化性能。涂层试样在1000℃静态空气中氧化2 h,质量损失在2%以内,远低于纯C/C试样及单一SiC涂层保护C/C试样。A SiC-SiC/TaC coating was prepared on carbon/carbon （C/C） composite by a two-step technique of pack cementation and sol-gel to protect C/C composite from oxidation. The surface and cross-section morphologies and phase composition of the coating was analyzed by SEM and XRD, respectively. The results show that a transitional SiC coating prepared by pack cementation process is a whisker-toughened protective coating and the compact out-coating prepared by sol-gel process can effectively fill the holes between whiskers of SiC coating by pack cementation and thickness of the coating increasing from 4 μm to 8 μm. The coating made by two-step technique exhibites excellent oxidation protective ability. The mass loss percentage of the coated C/C composite is only 2% after oxidation in air at 1000 ℃ for 2 h, which is far lower than pure C/C composite and C/C composite with SiC coating.

关 键 词：C/C复合材料 两步法 晶须增韧 抗氧化涂层 

分 类 号：TB332[一般工业技术—材料科学与工程]