摘要
对薄毡叠层结构的炭纤维预制体采用化学气相沉积(CVD)和沥青浸渍增密工艺,制备具有粗糙层热解炭结构和光滑层热解炭与沥青炭复合结构的2种炭/炭复合材料;用JR-3型热物性测试仪测试垂直炭纤维叠层方向室温至800℃的导热性能,并对其导热机制进行分析。研究结果表明:具有粗糙层热解炭结构的样件A的导热系数随温度升高先下降,在400℃后导热系数变化平缓;具有光滑层热解炭及少量沥青炭结构的样件B的导热系数随温度升高先上升,在300℃后导热系数变化平缓;样件A较样件B的导热系数高。2种炭/炭复合材料的导热机理主要由声子导热决定,不同基体炭结构使得2种声子散射机理对导热性能的贡献不一样,粗糙层热解炭结构的样件A的高温导热性能主要由声子间散射路程和比热容的综合作用所决定;光滑层热解炭和少量沥青炭复合结构的样件B的高温导热性能主要由结构不均匀引起的声子散射和比热容的共同作用所决定。
Two types of carbon/carbon（C/C） composites for thin felt laminate carbon fiber perform with rough laminar（RL） pyrocarbon structure and smooth laminar（SL） pyrocarbon and pitch carbon structure were fabricated by chemical vapor deposition and impregnation of pitch. The thermal conductivity properties for perpendicular to carbon fiber piling at room temperature to 800 ℃were investigated on a JR-3 thermophysical properties test apparatus. The mechanism of thermal conductivity was analyzed. The results show that the thermal conductivity coefficient of sample A with rough laminar（RL） pyrocarbon structure decreases with increasing temperature and keeps stable above 400℃. Thermal conductivity coefficient of sample B with smooth laminar（SL） pyrocarbon and pitch carbon structure increases with increasing temperature and keeps stable above 300℃. Thermal conductivity coefficient of sample A is higher than that of sample B. The mechanism of thermal conductivity for two kinds of C/C composites is determined by phonon conducting. Two kinds of phonon scatterings contribute differently to different matrix carbon. The thermal conductivity properties of sample A at high temperature are mainly determined by scattering distance between phonons and special heat. The thermal conductivity properties of sample B at high temperature are mainly determined by scattering of phonons aroused by asymmetric structure and special heat.
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2008年第3期500-505,共6页
Journal of Central South University:Science and Technology
基金
国家重点基础研究发展计划资助项目(2006CB600906)
关键词
炭/炭复合材料
薄毡叠层
高温
导热性能
C/C composites
thin felt laminate
high temperature
thermal conductivity property
