ZrB_2-SiC和C_(sf)/ZrB_2-SiC超高温陶瓷基复合材料烧蚀机理的研究  

Ablation Mechanism of ZrB_2-SiC and C_(sf)/ZrB_2-SiC Ultra-high Temperature Ceramic Composites

作　　者：杨飞宇[1] 张幸红[1] 韩杰才[1] 杜善义[1] 

机构地区：[1]哈尔滨工业大学复合材料与结构研究所,哈尔滨150080

出　　处：《无机材料学报》2008年第4期734-738,共5页Journal of Inorganic Materials

基　　金：国家自然科学基金(50602010);新世纪优秀人才计划基金(NCET-05-0345)

摘　　要：通过真空热压工艺制备了ZrB_2-SiC材料和C^(sf)(碳短纤维)/ZrB_2-SiC超高温陶瓷基复合材料.采用氧乙炔火焰在4186.8kW/m^2的热流下分别喷吹烧蚀两种材料180s.ZrB_2-SiC材料表面最高温度达到2406℃,烧蚀后质量烧蚀率为-0.14%,线烧蚀率为-1×10^(-3)mm/s,C_(sf)/ZrB_2-SiC材料表面最高温度达到1883℃,烧蚀后质量烧蚀率为-0.19%,线烧蚀率为-4×10^(-4)mm/s.对两种材料烧蚀表面和剖面的分析发现,ZrB_2-SiC材料烧蚀后由表及里依次形成了疏松ZrO_2氧化层、SiC富集层和未反应层的三层结构,其中SiC富集层能够起到抗氧化的作用.C_(sf)/ZrB_2-SiC材料烧蚀后由外到内分别形成了ZrO_2-SiO_2氧化层、SiC耗尽层和未反应层的三层结构,其中最外层以ZrO_2为骨架,SiO_2弥合其中的结构有效地阻挡了烧蚀中氧的侵入.ZrB2-SiC and Csf/ZrB2-SiC, two kinds of ultra-high temperature ceramic composites were fabricated by hot-pressing. The ablation behavior of them was studied by oxyacetylene torch test at a heat flux of 4186.8kW/m^2 for 180s. For ZrB2-SiC, the surface temperature increases to 2406℃ during torch test and the average mass loss is -0.14%, linear ablation rate is -1 × 10^-3mm/s. For Csf/ZrB2-SiC, the maximum surface temperature is 1883℃, and the average mass loss is -0.19%, linear ablation rate is -4×10^-4mm/s. From the surface and cross section analysis it is found that loosen ZrO2 oxidation layer, SiC rich layer and unaltered layer form from outer layer to inner layer in ablated ZrB2-SiC microstructure, where SiC rich layer has oxidation resistance. For Csf/ZrB2-SiC, ZrO2-SiO2 oxidation layer, SiC depletion layer and unaltered layer distribute from outer layer to inner layer, where the SiO2 filled ZrO2 oxidation layer formed in the surface can prevent oxygen effectively.

关 键 词：ZRB2-SIC Csf/ZrB2-SiC 超高温陶瓷基复合材料 烧蚀机理 

分 类 号：TB332[一般工业技术—材料科学与工程]