C/C-SiC复合材料的导热性能及其影响因素  

Thermal conductivity of C/C-SiC composites and its influence factors

作　　者：李专[1] 肖鹏[1] 熊翔[1] 黄伯云[1] 

机构地区：[1]中南大学粉末冶金国家重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2013年第1期40-45,共6页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(51205417;51072231);中国博士后科学基金资助项目(20110491278);中南大学自由探索计划项目(2011QNZT43))

摘　　要：以炭纤维针刺毡为预制体,采用化学气相渗透法和熔融渗硅法相结合制得C/C-SiC复合材料;研究C/C-SiC材料在室温至1 300℃之间的导热性能以及预制体结构、基体炭结构和石墨化处理对其热扩散率的影响。研究结果表明:C/C-SiC材料的比热容随着温度的升高不断增大,在700℃时达到最大值2.18 J/(g·K),随后降至1 300℃时的0.57 J/(g·K),其导热系数在1 300℃时为3.95 W/(m.K);C/C-SiC材料的热扩散率在室温时为0.12 cm2/s,随着温度的升高不断降低并趋于常量,平行摩擦面方向的热扩散率明显比垂直于摩擦面方向的大;以全网胎为预制体的C/C-SiC材料其垂直和平行摩擦面的热扩散率相当,树脂炭质量分数增大及石墨化处理均可显著提高C/C-SiC材料的热扩散率。Carbon fibre reinforced carbon and silicon carbide dual matrix composites （C/C-SiC） were fabricated by the combination of chemical vapor infiltration （CVI） with liquid silicon infiltration （LSI）. The effects on thermal conductivity of C/C-SiC composites were investigated. The results show that the specific heat capacity of C/C-SiC increases with the increase of temperature and reaches the highest value of 2.18 J/（g.K） at 700 ℃, and decreases to 0.57 J/（g-K） at 1 300 ℃. At the same temperature, the thermal conductivity of C/C-SiC is 3.95 W/（m＇K）. The thermal diffusivity of C/C-SiC decreases to constant with the increase of temperature. The thermal diffusivity parallel to friction surface is obviously larger than that perpendicular to friction surface. The thermal diffusivity paralled to friction surface is quite to that of perpendicularity of C/C-SiC using the preform as web, and the thermal diffusivity significantly increases with the increase of mass fraction of the resin carbon and the treatment of graphitization.

关 键 词：C C-SiC复合材料 导热系数 熔融渗硅 炭纤维 

分 类 号：TB331[一般工业技术—材料科学与工程] TH117.3[机械工程—机械设计及理论]