摘要
采用包埋-刷涂法在C/C复合材料表面制备SiC/ZrSiO_4复合涂层,借助X射线衍射(XRD)、扫描电镜(SEM)和能谱分析(EDS)等测试手段分析该复合涂层的微观结构,并研究Si C单涂层和SiC/ZrSiO_4复合涂层在1 500℃静态空气中的抗氧化性能。结果表明:包埋法制备的SiC内涂层结构疏松,具有较好的抗氧化性能,氧化55 h后质量损失率仅为0.5%,但氧化58 h后,涂层内部形成大孔洞并产生贯穿孔隙,导致涂层失效,质量损失率迅速增加到2.1%。SiC/ZrSiO_4复合涂层由非均质镶嵌式结构的ZrSiO_4涂层紧密覆盖在SiC内涂层表面而成,具有优异的抗氧化性能,氧化198 h后质量仅增加0.5%,并且基本不再随时间延长而增加;复合涂层不仅能自愈合外涂层的缺陷和裂纹,还能抑制氧化过程中大孔洞的形成,避免贯通孔隙的产生。
The SiC/ZrSiO4 coatings were prepared on carbon/carbon（C/C） composites by pack cementation （PC） and slurry painting method. The microstructures of the as-prepared coatings were characterized by XRD, SEM and EDS. The oxidation resistance of the single SiC coating and SiC/ZrSiO4 coatings were evaluated in ambient air at 1 500 ℃, respectively. The results show that the SiC coating prepared by PC with loose structure has good oxidation resistance. The mass loss rate of the single SiC coated sample is only 0.5% after for 55 h oxidation, but the coating begins to fail due to the penetrated pores formed by big holes generating inside the coating and the mass loss_rate reaches to 2.1% after oxidation for 58 h. While the SiC/ZrSiO4 coating exhibits more excellent oxidation resistance by forming ZrSiO4 coating with anisotropic inlaid structure on the surface of SiC inter coating, and can protect C/C matrix from oxidation for more than 198 h with a mass gain of 0.5%. The SiC/ZrSiO4 coatings can not only self-heal the defects and cracks in outside coating, but also inhibit the formation of big holes inside coating during the oxidation, then avoid the formation of penetrated defects.
出处
《粉末冶金材料科学与工程》
EI
北大核心
2015年第6期951-958,共8页
Materials Science and Engineering of Powder Metallurgy
基金
国家重点基础研究发展规划(973计划)资助项目(2011CB605804)
