循环吸湿对炭纤维复合材料界面性能的影响

通过对炭纤维增强复合材料进行70、85、100℃下的循环水浸吸湿试验,研究了复合材料在不同水浸温度下的吸湿-脱湿行为规律。同时,对循环吸湿-脱湿过程中的试样进行层间剪切强度测试和动态力学性能测试,并结合扫描电镜观察循环吸湿各个阶段的纤维基体结合状态。结果表明,水浸温度越高,水分的扩散速率越快,饱和吸湿率越大。经过循环吸湿后复合材料的吸湿行为仍满足Fick第二定律,吸湿后层间剪切强度下降,湿热循环次数越多下降的越明显。脱湿后层间剪切强度有所恢复,水浸温度越高造成的不可逆破坏越大,层间剪切强度恢复的越少。干态时的玻璃化转变温度为231℃,吸湿后下降了37℃。

Effect of cyclic hygrothermal environment on the interfacial property of carbon fiber composites

Circulating water leaching moisture absorption test in 70, 85 and 100℃ on woven carbon fiber epoxy resin compos-ite was carried out to analyze moisture absorption and desorption behaviors under different water temperatures. Meanwhile, the inter-laminar shear strength and dynamic mechanical properties tests for the sample in the process of circulation hygroscopic were conduc-ted. Combined with a Scanning Electron Microscope ( SEM) technique, the fiber matrix junction status of various stages after hygro-scopic damage was observed. The results show that the higher the water temperature is, the faster its diffusion rate is, and the grea-ter the saturated moisture absorption rate is. After circulating moisture absorption, moisture absorption behavior of the composite ma-terials still satisfy the Fick's second law, and inter laminar shear strength decreases after moisture absorption, and the more heat cy-cle goes, the more obvious inter laminar shear strength decreases. Inter laminar shear strength recover after dehumidifying. The higher the temperature is, the greater the irreversible damage caused by the water temperature is, resulting in the less recovery of inter lami-nar shear strength. The glass transition temperature of dry state is 231℃,and decreased 37℃ after moisture absorption.