界面热阻实验装置与碳纤维增强板胶接热阻研究

Study on experimental device and measurements for interface thermal resistance of adhesive structure of CFRP

碳纤维增强板(CFRP)胶接结构是高精度固面反射器的重要组成部分,而热载荷是反射器在轨飞行的主要载荷,胶接部位的界面热阻对高精度固面反射器在轨运行状态的温度分布有重要影响.根据界面热阻测量原理,设计了一套可测量真空环境中不同温度下CFRP单片结构的热导率和胶接结构的界面热阻的实验装置.并且通过304不锈钢热导率的实验测量值与标准值的对比,验证了实验装置的准确性.通过对环氧树脂胶添加高热导材料,提高了它的热导率.实验中采用了3种添加剂:氮化硅(β-Si3N4)、氧化铝(Al2O3)、石墨烯.实验结果表明,随着添加剂体积分数的增加,热导率也随之增大,进而可以强化胶接部位的传热,减小界面热阻.在其他条件一致的情况下,胶接件的界面热阻随温度的升高而减小.

The adhesive structure of carbon fiber reinforced plastics(CFRP)is an important part of the high precision solid surface reflector,the thermal load is the main load of the reflector in orbit,and the interface thermal resistance has an important influence on the temperature distribution of high precision solid surface reflector in orbit.According to the principle of interface thermal resistance measurement,an experimental device was designed to accurately measure the thermal conductivity of CFRP monolithic structure and the interface thermal resistance of cementation structure at different temperatures.The accuracy of the experimental device was verified by comparing the measured thermal conductivity of 304 stainless steel with the standard values.To improve the thermal conductivity of epoxy resin,three single additives were introduced:silicon nitride(β-Si3N4),alumina(Al2O3),and graphene.The experimental results show that as the volume fraction of additives increases,the thermal conductivity also increases,thus enhancing the heat transfer at the bonding sites and reducing the interface thermal resistance.Under the same conditions,the interface thermal resistance of the adhesive decreases with the increase of temperature.