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本文通过模压法制备了酚醛纤维增强钡酚醛复合材料,并研究了该复合材料在室温下的弯曲性能、短梁剪切性能及其破坏模式;研究了该复合材料经高温热处理后的弯曲性能及其破坏模式;通过氧-乙炔实验测试了该复合材料的烧蚀性能,对烧蚀形貌的微观进行分析,研究其在高热环境中材料失效特征。实验结果表明,酚醛纤维增强酚醛树脂复合材料在室温条件下受力作用时,复合材料的弯曲强度与模量低于树脂基体,脆性断裂,显示树脂特性;复合材料经高温热处理后,树脂基体热解收缩,酚醛纤维炭化保持纤维形状,连接分裂的树脂基体,表现出纤维增强特征。复合材料烧蚀过程中纤维与树脂同步热解,质量损失率达0.06g/s,烧蚀形貌微观分析表明,纤维与基体在同步炭化过程中纵向柱状生长,碳层纵向结合较好。
In this paper, the phenolic fiber-reinforced barium phenolic composites were prepared by compression molding method. The flexural properties, short-beam shear properties and failure modes of the composites were studied. The flexural properties of the composites after heat treatment at high temperature were studied. The failure mode of the composite was tested. The ablation performance of the composite was tested by oxygen-acetylene experiment. The microstructure of the ablation morphology was analyzed and the failure characteristics of the composite in the hot environment were studied. The experimental results show that the flexural strength and modulus of the composites are lower than that of the matrix and brittle fracture, which shows the resin properties when the phenolic fiber reinforced phenolic resin composites are subjected to force at room temperature. After heat treatment of the composites, the matrix heat Solution shrinkage, phenolic fibers carbonized to maintain the shape of the fiber, connecting the split resin matrix, showing the fiber-reinforced features. During the ablation process, the fibers were pyrolyzed simultaneously with the resin. The mass loss rate was 0.06 g / s. The microscopic analysis of the ablation morphology showed that the fibers and the matrix grow vertically in the process of simultaneous carbonization and the carbon layer is well bonded longitudinally.