碳纤维增强陶瓷基复合材料高温拉伸性能研究

Study on the High Temperature Tensile Properties of Carbon Fiber Reinforced Ceramic Matrix Composites

为进一步提高以碳化硅为主要基体的陶瓷基复合材料的高温力学性能,对材料高温拉伸性能的变化规律和影响因素进行了评价和分析。结果表明,随着温度的升高材料拉伸性能呈现先上升后下降的变化趋势,碳化硅基体结晶程度逐渐提高,晶粒尺寸逐渐长大并出现团聚,导致内部缺陷孔洞增多,造成材料高温性能下降;材料热处理温度、致密化度的提高对材料的高温性能具有改善作用,使材料在经历最高温度2000℃,总时长3000s热环境条件下测试时性能保留率达82.4%。

In order to further improve the high temperature mechanical properties of the ceramic matrix composites with silicon carbide as the main matrix,the variation law and influencing factors of the high temperature tensile properties of the composites are studied.The results show that with the increase of temperature,the tensile properties of the materials increase at first and then decrease the crystallization degree of silicon carbide matrix increase gradually,and the grain size increase and aggregates,which leads to the increase of internal defect pores and the decrease of high temperature properties of the composites.The increase of heat treatment temperature and densification degree of the composites can improve the high temperature properties of the composites,which make the high temperature tensile strength retention of the composites up to 82.4%after the themal process with a maximum temperature of 2000℃and a total time of 3000s.