TiC_p/W复合材料的热物理性能

Thermophysical Properties of TiC_p/W Composites

摘要:

采用热压烧结工艺制备了 Ti Cp/ W系列复合材料 ,分析测试了温度和 Ti C含量对复合材料的热物理性能的影响规律。结果表明 :随着温度的升高 ,复合材料的定压比热和平均线膨胀系数单调增大 ,热扩散率稍有减小 ,热导率略有增大。随 Ti C含量的增加 ,复合材料的定压比热和平均线膨胀系数线性增大 ,基本满足混合定律。热扩散率和热导率对材料的组织结构比较敏感 ,二者均随 Ti C含量的增加而急剧减小。热导率的实测值大大低于理论计算值 ,这主要是由晶界和孔洞等缺陷对导热粒子的强烈散射作用造成的。

关键词:W基复合材料,TiC颗粒,热物理性能

Abstract:

Titanium carbide particle reinforced tungsten matrix (TiC p/W) composites were fabricated using a hot pressing technique The effects of temperature and TiC p content on the thermophysical properties of the composites have been investigated The results show that as temperature increases, specific heat and coefficient of thermal expansion increase monotonically, thermal diffusivity decreases slightly, and thermal conductivity increases gradually The specific heat and the coefficient of thermal expansion of TiC p/W composites increase with increasing TiC p content, according to the mixture ruler The thermal diffusivity and conductivity of TiC p/W composites, which are sensitive to microstructure, decrease greatly with increasing TiC p content The experimental values of the thermal conductivity are considerably lower than the theoretical ones as result of diffraction from defects such as grain boundary and pores in the thermal conducting particles

Key words:tungsten matrix composite, TiC particle, thermophysical property