毡基碳/碳复合材料氧化动力学研究

本文研究了不同温度(773～1173K)条件下,毡基碳/碳复合材料的氧化动力学行为,并利用扫描电镜观察分析了不同氧化程度的碳/碳复合材料显微组织。实验结果表明:毡基碳/碳复合材料在各温度下氧化速度均不随时间而变化。在高于和低于873K时,其氧化机制不同,二者的活化能分别为128kJ/mol和96kJ/mol;同时,碳/碳复合材料氧化过程中。碳毡优先氧化,随着氧化过程进行到后期,基体碳氧化程度加剧。另一方面,毡基碳/碳复合材料的氧化速度主要受该材料的表面反应、气体扩散、催化剂等因素的影响。

INVESTIGATION ON THE OXIDIZATION KINETICS OF FELT BASE CARBON/CARBON COMPOSITES

In this paper,the kinetics of air oxidation of felt base carbon/carbon composites is investigated at different temperatures (773-1173 K). With the help of SEM, the micrographs of carbon/carbon composites are studied after different debrees of oxidation.The experimental results are shown that the oxidation rate of felt base carbon/carbon composites is constant at a given temperature.When the oxidation temperature is below and above 873k,the oxidation mechanisms of carbon/carbon composites are different and their apparent activation energies are 96 kJ/mol and 128 kJ/mol respectively.During the carbon/carbon composites oxidation initial stage,carbon felt is oxidized much more rapidly than matrix carbon,while during the carbon/carbon composites oxidation final stage,oxidation rate of matrix carbon increases.Otherwise,the oxidation rate of felt base carbon/carbon composites is influenced by the carbon/carbon composite surface reaction rate,the gas phase diffusion and the catalysts.