摘要
研究了三维角联锁碳纤维复合材料未老化及90℃、110℃、180℃老化16 d的弯曲力学性能。对比三维角联锁复合材料弯曲-挠度曲线、破坏形态及SEM纤维特征,分析老化温度对复合材料弯曲性能的影响。通过环氧树脂DSC分析、红外光谱分析说明老化温度对树脂热学性质、后固化现象及分子结构变化的影响。结果表明:环氧树脂老化过程存在后固化和热降解两种竞争机制,90℃老化16 d的复合材料后固化作用突出,与未老化复合材料相比其弯曲强度增大;110℃老化16 d的复合材料热降解作用占优势,材料起始破坏弯曲强度略有下降;上述两者弯曲模量基本不变,而180℃老化16 d的复合材料热降解剧烈,树脂与纤维之间严重脱粘,材料弯曲强度明显下降,弯曲模量减小。
In this paper, the bending properties of 3-D carbon/epoxy interlock composite unaged and aged for 16-days at different temperature （90℃, 110℃, 180 ℃ ） were studied by quasi-static loading. The influences of aging temperature on bending properties were observed by macroscopic observation and SEM as well. The influences of aging temperature on epoxy properties, post-curing, heat flow and chemical structure were studied by differential scanning calorimetry （DSC） and infrared spectrum （IR Spectrum）, respectively. The result indicated as follows. The post-curing and thermal degradation can be found in epoxy aging at the same time. For Composite aged for 16 days, the bending strength of composite aged at 90 ~C increased obviously because the post-curing of epoxy play an important role in aging. When composite aged at 110 ℃ , the bending strength decreased unobviously which were caused by slightly thermal degradation. For composite aged at 180℃, the bending strength declined distinctly and the flexural modulus decreased as well due to the strong thermal degradation of the epoxy resin and the fiber/resin interface crack which were observed by SEM. In addition, less damage area on top of composite aged at 90℃ than others could be found form the damage photographs. These were consistent with the strength characteristics which in- dicated in above situation that composite aged at 90℃ had better bending properties.
出处
《玻璃钢／复合材料》
CSCD
北大核心
2017年第6期80-84,共5页
Fiber Reinforced Plastics/Composites
