热压烧结C_p/SiC复合材料的低温氧化行为研究

Low-temperature oxidation behavior of hot-pressed C_p/SiC matrix composites

采用热压烧结技术成功制备Cp/SiC基复合材料,并对其进行短时间低温氧化行为研究。针对不同碳粉含量的Cp/SiC复合材料,分析氧化处理过程对其相组成、氧化层结构以及质量损失行为的影响。研究结果表明,随着碳粉含量增加,氧化层表面的孔洞尺寸和深度均呈现出增加的趋势。氧化层与碳化硅基体的分界清晰,无过渡区,不能形成致密氧化层,反应氧化层厚度也逐渐增加。添加碳粉不利于SiC基复合材料的抗氧化性的改善。

Cp/SiC matrix composites were fabricated by the hot pressure sintering technology, and low-temperature short-term oxidation behavior was studied. The effect of oxidation process on the phase constitution, microstructure and mass loss behavior of Cp/SiC matrix composites with different carbon powder content was analyzed. The results show that the porosity size and thickness of the oxidation layer have the increasing tendency with carbon powder content increasing. The interface between oxidation layer and SiC matrix is clear and without transition zone, so the dense oxide layer can not be formed. The thickness of the oxide layer is gradually increased with carbon powder content increasing. The addition of carbon powder is unfavorable for the improvement of oxidation resistance of Cp/SiC matrix composites.