C/SiC复合材料的氧化对其内耗行为的影响

通过分析C/SiC在高温(1250、1300和1350℃)空气氧化过程中质量、强度、物相、气孔率、微观形貌演变规律, 并同时采用动态热机械分析仪测得内耗的变化趋势, 研究了氧化对其内耗行为的影响规律, 进而为以内耗表征复合材料的氧化行为奠定基础。为明确C/SiC各组元在氧化与内耗行为对应关系中所发挥的作用, 进一步研究了SiC陶瓷在1300℃、空气中的氧化与内耗行为之间的对应关系。结果表明: SiC陶瓷氧化对其内耗行为的影响规律不明显且影响程度较弱; C/SiC在氧化过程中的内耗行为受C相的氧化损伤控制, 且作用规律明显, 其内耗保持率曲线均出现峰值, 其中1250、1300和1350 ℃的峰值分别为6.65、3.48和1.59。

Effect of oxidation on internal friction behavior of C/SiC composites

The effect of oxidation on internal friction behavior of C/SiC composites was investigated to lay foundation for evaluating the oxidation behavior using the internal friction, by analyzing the change of the porosity, mass, flexural strength, phase, microstructure and also measuring the internal friction by thermal mechanical analyzer during oxidation at elevated temperature (1250, 1300 and 1350℃) in air. The relationship between oxidation and internal friction for SiC ceramics was also studied at 1300℃ in air, to clarify the affect of oxidation of each component in C/SiC on the internal friction behavior. The results show that the effect of oxidation on internal friction for SiC is irregular and weak; the internal friction behavior of C/SiC is controlled obviously by the oxidation of carbon phase and the peak value of internal friction retention at 1250, 1300 and 1350℃ is 6.65, 3.48 and 1.59, respectively.