ZrC、ZrC-TaC增强石墨基复合材料的超高温氧化行为  

Ultra-High Temperature Oxidation Behavior of Graphite-Based Composites Reinforced by ZrC and ZrC-TaC

作　　者：徐敬军[1] 李美栓[1] 高增华[1] 房学良[2] 张中伟[2] 

机构地区：[1]中国科学院金属研究所,沈阳110016 [2]航天材料及工艺研究所,先进功能复合材料技术国防科技重点实验室,北京100076

出　　处：《宇航材料工艺》2011年第1期66-70,共5页Aerospace Materials & Technology

摘　　要：利用自建的可控气氛感应加热超高温氧化装置研究了ZrC、ZrC-TaC颗粒增强石墨基复合材料在1 900和2 100℃下空气及0.2×105Pa的纯氧气中的氧化行为。结果表明,石墨以及颗粒增强石墨基复合材料的径向线度随氧化时间直线减小,在1 900和2 100℃下的氧化烧蚀速率:石墨为3.4和4.3 mm/s,C-ZrC为1.9和2.4 mm/s,C-ZrC-TaC为1.4和2.0 mm/s。添加增强相后使得石墨在1 900和2 100℃的空气中氧化540 s后烧蚀速率分别降低了60%和54%。在2 100℃下,C-ZrC在0.2?05Pa O2中的氧化速率是其在空气中的2倍多。综合考虑材料的氧化动力学规律以及氧化温度、气氛的总压及氧分压的影响,提出了超高温氧化边界层扩散控制模型。The oxidation resistance of ZrC and ZrC-TaC reinforced graphite was tested at 1 900℃ and 2 100℃ in air and 0.2×105 Pa pure oxygen by using an ultra-high temperature oxidation facility with induction heating.The experimental results indicate that the radius of the cylinder graphite and graphite-based composites decreased with oxidation time linearly.The corresponding ablation rate is 3.4/4.3 mm/s for graphite,1.9/2.4 for C-ZrC and 1.4/2.0 for ZrC-TaC/C-ZrC-TaC at 1 900℃ and 2 100℃,respectively.It is found that the samples encountered more severe oxidation under pure oxygen environment.For example,the oxidation rate of C-ZrC in pure oxygen is more than twice of that in air at 2 100℃.An oxidation model with oxygen inward diffusion through boundary layer as predominant step is proposed to explain the oxidation law and the influence of temperature,total gas and oxygen partial pressure.

关 键 词：超高温 氧化 石墨基复合材料 感应加热 

分 类 号：TQ174.758[化学工程—陶瓷工业]