C/C复合材料导热性能的比较研究  

COMPARAISON OF C/C COMPOSITES THERMAL CONDUCTIVITY

作　　者：王连星[1] 李凤仙[2] 周晓龙[1] 金鸣林[2] 陈麒忠[2] 

机构地区：[1]华东理工大学化工学院,上海硕士生200237 [2]上海应用技术学院材料科学与工程学院,上海硕士生200235

出　　处：《煤炭转化》2011年第4期62-65,71,共5页Coal Conversion

基　　金：上海市科技发展基金资助项目(09520500700);上海市教委重点学科基金资助项目(J51504)

摘　　要：选择了三种不同基体炭为主体,经成型、炭化与浸渍制备的样品为对象,采用扫描电镜(SEM),XRD和热导率测定等分析手段,分别研究了石墨化前后C/C复合材料的微观结构形态及导热性能变化.结果表明,炭化样品的视密度为1.61g/cm3～1.70g/cm3,石墨化度较低,且热导率较小.以D8μm单束丝经两维编制的样品呈现出整齐排列,热传导各向异性比为4.7倍.采用非编制纤维束黏结压制成型的样品以及石墨粉压制成型的样品,其导热性能在两维方向上表现为各向同性.2 700℃石墨化后样品的视密度在1.61g/cm3～1.69g/cm3,没有显著变化.热导率随石墨化度提高而增大,最大增幅达到石墨化前的15倍.单束丝样品热传导各向异性比从4.7扩大到6.3.非编制纤维束黏结压制成型样品的导热性仍保持各向同性,径向为222.27W/(m.K),轴向为243.40W/(m.K);此外,在室温～300℃范围内,2 700℃石墨化后C/C复合材料的热导率均随温度升高呈现出不同程度的下降趋势.Three samples made from different matrix carbon,after forming,carbonized and dipping process were chosen to study the microscopic structures and thermal conductivity of the block C/C composites before and after graphitization.They were separately measured by such means as SEM,XRD and thermal conductivity measurement.The results show that the apparent densities of the carbonized samples are 1.61 g/cm3-1.70 g/cm3 and the thermal conductivities are relatively low.The microstructure of the sample made by D 8 μm single cabon fiber weaving in two dimensions is in order and its anisotropic index of the heat conduction is about 4.7.But the thermal conductivity of samples produced by non-woven fiber bundle molded under pressure technology and graphite powder molded under pressure technology behave the isotropic characteristics in two dimensional direction.After 2 700 ℃ graphitization,the apparent densities of the samples are 1.61 g/cm3-1.69 g/cm3,having no significant changes.The thermal conductivities increase significantly,the maximum growth is 15 times than before,and the anisotropic index of the heat conduction in the single cabon fiber weaving sample enlarges to 6.3.The thermal conductivity of the sample made by non-woven fiber bundle molded under pressure technology remains isotropic,which is the highest,with 222.27 W/（m·K） in radial and 243.40 W/（m·K） axial respectively.In addition,from the room temperature to 300 ℃,the thermal conductivities of C/C composites decline gradually with the raise of the temperature.

关 键 词：炭炭复合材料 炭纤维 石墨化 热导率 各向异性比 

分 类 号：TQ050.421[化学工程]