摘要
对不同温度下化学液气相渗透工艺 ( CLVD)制备的 C/C复合材料物理性能和力学性能变化进行了研究 ,揭示了温度在此工艺中的关键作用以及对材料性能的影响。在 85 0℃～ 1 1 0 0℃ ,C/C复合材料的质量增加 ,表观密度及总孔隙率均随时间呈线性变化 ;其化学反应的活化能为 1 1 7.4k J/mol,说明沉积化学反应成为控制反应机制。三点弯曲测试表明 ,C/C复合材料弯曲强度在此区间内随温度升高先增大后减小 ,弯曲模量却一直减小 。
The changes of physical properties and mechanical properties of carbon fiber felts infiltrated with pyrocarbon by CLVD between 850℃ and 1 100℃ were investigated.Between 850℃ and 1 100℃ mass increase,apparent density,porosity as a function of time were linear,and the apparent activation energy of the chemical reaction calculated was 117.4 kJ/mol.Because of the high value of Ea,the kinetics is only dependent on the chemical reaction producing the pyrocarbon.The results by three-point flexural tests indicate flexural strengths of C/C composites first increase,then decrease and flexural modulus keep decreasing from 850℃ to 1 100℃.The changes are due to the quantity and the uniformity of the defects in the composites and the changes of the microstructure,respectively.
出处
《炭素》
2002年第1期24-28,45,共6页
Carbon
