孔隙率对碳纤维复合材料超声衰减系数和力学性能的影响

复合材料的工艺过程对最终产品的力学性能具有决定性影响,但其机理十分复杂。通过设置一系列固化压力历程以产生不同水平的孔隙率,采用超声C扫描、显微镜分析和酸解法对孔隙的分布、形状、尺寸和体积含量进行了定性和定量表征。讨论了孔隙率对层压板层间剪切性能、弯曲性能和拉伸性能的影响规律,获得了性能下降的临界孔隙率值。结果表明:孔隙率对性能的影响只受孔隙含量、分布、尺寸和形状等的影响,而与产生方式没有直接联系。本文作者的研究将工艺参数、孔隙率和性能有机地联系起来,体现了复合材料设计、制备与性能一体化的特点。 

EFFECTS OF POROSITY ON THE ULTRASONIC ABSORPTION COEFFICIENT AND MECHANICAL STRENGTH OF CARBON/EPOXY COMPOSITES

The process procedure of composites has decisive effects on the mechanical strength of the end product, but the mechanics is rather complicated for the process. A set of cure pressures were applied to produce various void contents. Qualitative and quantitative characterization of porosity in terms of void distribution, shape, size and volume fraction was carried out by ultrasonic C-scan, microscopic analysis and acid digestion methods. Effects of porosity on the interlaminar shear strength, flexural strength and tensile strength for the laminates were discussed and the critical value of void content at which the strength began to decrease was also obtained. The results show that the effects of porosity on the strength are mainly attributed to the void content, void distribution, size and shape, and the void content has little connection with the generation method. The investigation of this paper correlates the process parameter, porosity and performance, and embodies the integrated characteristics of design, manufacture and performance of composites.