热压工艺参数对单向复合材料层板密实状态的影响

为了提高复合材料的质量稳定性并降低成本, 需要研究纤维密实状态的变化规律及其影响因素。采用密实指数I_c表征单向复合材料层板中纤维的密实程度, 进而研究了热压工艺下压力、加压时机及铺层层数对密实指数的影响规律。结果表明, 密实指数随压力的增大呈非线性增大, 随加压点树脂粘度的增大而减小, 随铺层层数的增大呈线性减小。该研究结果为优化热压成型工艺窗口和短程流动模型的建立提供了重要的实验依据。 

Effects of hot pressing process on f iber compaction of unidirectional composite laminates

To control the degree of fiber compaction, insure the quality of composites and reduce the cost, it is necessary to study how the state of fiber compaction changes and the factors that affect it. A parameter which is called compaction index Ic is used to show the degree of fiber compaction of unidirectional composite laminates. The greater the Ic, the greater the degree of fiber compaction. For the hot pressing process, the effects of pressure, timing of the applying pressure and the number of layers on Ic were analyzed by means of optical microscope along the thickness of the laminates. The results show that Ic increases nonlinearly with pressure, decreases with the increase of resin viscosity at the timing of applying pressure and reduces linearly with the number of layers. These results provide some important experimental evidence to optimize the hot pressing process and establish a short-distance flow model.