C/C多孔体热处理温度对C/C-SiC复合材料微观结构和热学性能的影响  

Effect of heat treatment temperature of C/C porous preform on microstructure and thermal properties of C/C-SiC composites

作　　者：虎琳 李崇俊[1] 张永辉[1] HU Lin;LI Chong-jun;ZHANG Yong-hui(Xi＇an Aerospace Composite Materials Research Institute, Xi＇an 710025, China)

机构地区：[1]西安航天复合材料研究所,西安710025

出　　处：《炭素》2018年第1期18-23,共6页Carbon

摘　　要：以针刺网胎无纬布为预制体,采用化学气相渗透(CVI)、压力浸渍树脂/炭化(PIC)及反应熔体浸渗法(RMI)等组合工艺快速制备C/C-SiC复合材料。研究了C/C多孔体的高温热处理温度对C/C-SiC复合材料微观结构和热学性能的影响,结果表明:多孔体经高温热处理后密度有所减小而孔隙率增大;相较于1800℃热处理,多孔体经2200℃热处理后制备的C/C-SiC复合材料密度更大(ρ=2.12g/cm3),孔隙率更低(η=2.7%),SiC基体含量更高(ω=41.11%);C/C-SiC复合材料的比热容和平均热膨胀系数随着温度的升高而增大,而热扩散系数和导热系数随着温度的升高不断减小;多孔体经2200℃热处理后制备的C/C-SiC复合材料X-Y向具有更大的导热系数和更小的热膨胀系数,其室温下的导热系数为83.120W/(m·K),室温~1000℃的平均热膨胀系数为1.608×10-6/℃。The C/C-SiC composites were fabricated by the combination of chemical vapor infiltration,resin impregnation/ carbonization and reactive melt infihration. The effects of heat treatment temperature （ HTT ） of C/C porous preform on microstrueture and thermal properties of C/C-SiC composites were investigated. The results show that the density of C/C porous preform decreases and the porosity increases after HTT. Compared with 1800℃,C/C-SiC composites prepared by HTT at 2200℃ have higher density （ p =2.12g/cm^3 ） and lower porosity （η =2.7% ）,and the content of SiC （ to =41.11% ） is higher. The specific heat capacity and the average coefficient of thermal expansion （ CTE ） of C/C-SiC composites increase with the increase of temperature,while the thermal diffusion coefficient and thermal conductivity decrease with the increase of temperature. The C/C-SiC composites prepared by HTT at 2200℃ have higher thermal conductivity and smaller thermal expansion coefficient,and the thermal conductivity at RT is 83.120W/ （ m·K ）,the CTE at RT-1000℃ is 1.608×10^-6/℃.

关 键 词：C/C—SiC复合材料 反应熔体浸渗法 微观结构 热学性能 

分 类 号：TQ165[化学工程—高温制品工业]