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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 ,这主要是材料中缺陷多少和分布均匀性以及材料微观结构变化造成的
The changes of physical and mechanical properties of C / C composites prepared by chemical vapor infiltration process (CLVD) at different temperatures were studied, and the key role of temperature in the process and the influence on the material properties were revealed. At 85 0 ℃ ~ 110 ℃, the mass of C / C composites increases, while the apparent density and total porosity change linearly with time. The activation energy of the chemical reaction is 1 1 7.4k J / mol, indicating that Deposition of chemical reactions to control the reaction mechanism. Three-point bending test shows that the flexural strength of C / C composites increases first and then decreases with the increase of temperature, and the flexural modulus decreases all the time. This is mainly due to the number and distribution of defects in the material and microstructure changes Caused