为了探究C/SiC陶瓷基复合材料的动态断裂力学行为和破坏形态,利用分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)装置对3种不同短切碳纤维体积分数的C/SiC陶瓷基复合材料进行了动态劈裂实验,并利用扫描电子显微镜扫描了C/SiC复合材料试件的破坏界面,分析了C/SiC陶瓷基复合材料的失效特征和增韧机理。实验结果表明:C/SiC复合材料在冲击劈裂实验过程中,同一短切碳纤维体积分数下试件的动态抗拉强度随着冲击气压的增大而增大;短切碳纤维体积分数为16.0%时,材料的抗拉强度最低;冲击后,试件的整体破坏情况与冲击气压、短切碳纤维体积分数有关。
In order to investigate the dynamic fracture mechanics behavior and damage morphology of C/SiC ceramic matrix composites,dynamic splitting tensile tests on the C/SiC composites with three different volume fractions of short carbon fiber(16.0%,21.0%,24.8%)were carried out by the split Hopkinson pressure bar,the destructive interface part of C/SiC composites was scanned by using scanning electron microscopy and the failure characteristics and toughening mechanism of C/SiC composites were analyzed.The experimental results show that the dynamic tensile strengths of the C/SiC composite specimens with the same short carbon fiber volume fraction increase with the increasing of the impact pressure in the dynamic splitting tensile failure process,the failure of the specimens is significantly correlated with impact pressure and short carbon fiber volume fraction.When the short carbon fiber volume fraction is 16.0%,the tensile strength of the C/SiC composite specimens is the lowest.After the impact,the overall destruction of the C/SiC composite specimens is related to impact pressure and short carbon fiber volume fraction.