后处理温度对EP/CF复合材料拉伸性能影响

采用模压成型工艺和拉挤工艺制备了加捻碳纤维增强环氧树脂(EP/CF)复合材料,利用微机控制电液伺服万能试验机和扫描电子显微镜研究了不同后处理温度对EP/CF复合材料的拉伸性能和断面微观形貌的影响。研究表明,相对于高温后处理下的EP/CF复合材料,室温后处理下的EP/CF复合材料的拉伸强度较优,其拉伸强度接近890 MPa;而随着后处理温度的升高,EP/CF复合材料的截面和表面显微硬度值呈先上升后下降趋势,当后处理温度为150℃时,其硬度值最优。随着后处理温度的上升,样品的断面形态由撕拉态变为剪切状态,整个断面转变为脆性断面,EP与CF之间的界面变差。较优后处理工艺为低温后处理;同时,常温固化剂下的EP和CF体系选择后处理工艺优化时,后固化温度应接近固化体系温度进行优化处理。

Effects of Post-Treatment Temperature on Tensile Properties of EP/CF Composite

Twisting carbon fiber reinforced epoxy resin (EP/CF) composite was produced by compression molding and pull extrusion processes. The effect of post treatment temperature on tensile property and fracture surface morphology of the composite were studied using universal testing machine and scanning electron microscope. The results show that compared withthe EP/CF composites under high temperature post treatment, the tensile strength of the EP/CF composites under room temperature post treatment is better and the tensile strength is near to 890 MPa. With the post treatment temperature increasing, the micro hardness of the surface and cross section of the composite material increase first and then decrease. The hardness of the EP/CF composite is the best when the post-treatment temperature is 150℃. The fracture form of the composite is changed into a shear state. The fracture state becomes brittle, and the interface between the resin and carbon fiber is poor. The better post treatment process is obtained after low temperature treatment, and the composite are prepared under normal temperature curing agent curing EP/CF system, and the post curing temperature should be close to the curing system temperature to optimize the performance of the composite.