【作者】 李莉；

【导师】 秦伟；

【作者基本信息】 哈尔滨工业大学 ， 材料学， 2008， 硕士

【摘要】 为了揭示碳纤维/氰酸酯复合材料在空间环境因素作用下的损伤效应和机理,分别研究了在-100℃～+100℃真空热循环和160keV空间电子、质子及其综合辐照条件下,T700/氰酸酯复合材料力学性能、质量损失、热膨胀系数等性能的变化规律,并采用FT-IR、XPS、SEM等现代分析测试手段对空间环境作用前后材料的微观结构进行了分析和表征。研究结果表明,随真空热循环次数的增加,复合材料的拉伸、层间剪切、弯曲、纵横剪切强度先呈上升趋势,在热循环100次时达到最大值后开始降低。经过180次真空热循环前后复合材料的纵向热膨胀系数曲线几乎没有变化;横向热膨胀系数略有下降,但变化不大,这说明T700/氰酸酯复合材料具有良好的尺寸稳定性。在160keV能量空间电子、质子综合辐照条件下,T700/氰酸酯复合材料在经过1.0×1016/cm2注量辐照后,材料的拉伸、层间剪切强度、弯曲强度和纵横剪切强度均有所提高;在辐照注量超过1.0×1016/cm2后,随辐照注量的继续增加,拉伸强度和层间剪切强度下降,弯曲强度和纵横剪切强度略有下降但变化不大。质量损失随辐照注量的增加而增加,在2.0×1016/cm2辐照注量后趋于平缓。质量损失一方面由所吸附的气体、溶剂和小分子助剂挥发所致;另一方面由于主链化学键发生破坏,形成小分子产物从试样表面逸出。当空间质子、电子单独作用于材料时,力学性能的变化规律与综合辐照影响规律一致。T700/氰酸酯复合材料的空间综合环境效应不是单一环境效应的简单叠加。空间电子辐照损伤效应最大,综合辐照次之、空间质子辐照最小。经过真空热循环后,性能变化主要由于交联密度和界面脱粘程度变化所引起的,没有发生新的化学反应;在空间电子质子综合辐照作用下,复合材料性能的变化与树脂基体交联密度的变化密切相关。更多还原

【Abstract】 In order to reveal the damage effects and mechanisms of space environments on carbon fiber/ cyanate resin composites, the changes in mechanical properties、mass loss and thermal expansion coefficients of carbon fiber/cyanate resin were investigated under vacuum thermo-cycling at the interval of -100℃～+100℃and proton irradiations、electron irradiations individually or simultaneously with 160keV. FT-IR、XPS、EPR and SEM were used to characterize the microscopic structure of composite before and after the action of space environments.Experimental results show that in the period of 100 times thermo-cycling, with increasing the cycles of vacuum thermo-cycling, tensile strength、interlayer shear strength、bend strength and cross shear strength increased. Then after 100 times thermo-cycling, the four strengths descend with the thermo-cycling times increases continully. After 180 times of thermo-cycling, the longitudinal thermal expansion coefficient is almost constant, the transverse thermal expansion coefficient reduces a little, which indicates that the composites has good size stability.Under the irradiation flux of 1.0×1016/cm~2, the tensile strength, interlayer shear strength, bend strength and cross shear strength increase. Then after the 1.0×1016/cm~2 irradiation flux, the four strengths descend with the irradiation flux increases. And the bend strength and cross shear strength reduces a little. With the irradiation flux increases, the mass loss accordingly increases. After the 2.0×1016/cm~2 irradiation flux, the mass loss becomes steady. The mass loss is attributed to the volatilization of gas、solvent and small molecule assistant adsorbed on material and small molecules come from the breakage of chemical bond. When the protons or electrons act on the material individually, the changes in mechanical properties are similar to it under the irradiations of both protons and electrons. The effects of synergistic environments in carbon fiber/ cyanate resin composites are not equal to the superposition of every single environment. And, compared the damage effects, proton irradiations is largest, the second is the irradiations of both protons and electrons, the last is electron irradiations. After vacuum thermo- cycling, the change of properties are mainly owing to the change of the coupling density of chemical bond and interface linking intensity, and there is no new chemic reaction. Under the effect of both proton and electron irradiation, the properties are mostly correlative to the coupling density of the resin.更多还原