C/SiC复合材料的动态力学性能及微观结构分析  

Dynamic Mechanical Properties and Microstructure of C/SiC Composites

作　　者：邵彬彬 徐颖[1,2] 许维伟[1] 郑志涛[1] 

机构地区：[1]安徽理工大学土木建筑学院,安徽淮南232001 [2]安徽理工大学矿山地下工程教育部工程研究中心,安徽淮南232001

出　　处：《材料科学与工程学报》2016年第4期603-606,642,共5页Journal of Materials Science and Engineering

基　　金：国家自然科学基金资助项目(51174004);高等学校博士学科点专项科研基金资助项目(20123415110001)

摘　　要：对三种不同短切碳纤维体积含量(16%、21%、24.8%)的C/SiC复合材料利用分离式霍普金森压杆(SHPB)装置进行了常温下的冲击力学试验,并利用扫描电子显微镜(SEM)对试件破坏后的断口进行扫描。实验结果表明:C/SiC复合材料试件动态单轴抗压强度随应变率的增加而增大,表现出较强的应变率效应。在各个复合材料试件的断口均有明显的纤维拔出,随着碳纤维体积含量的增加,断口处被拔出的纤维数量显著增多,且拔出后的长度也相对较长,说明试件制备过程中短切碳纤维与碳化硅基体的结合较紧密,增韧效果也就越理想,由此可以推断纤维拔出是C/SiC陶瓷基复合材料的主要吸能和增韧机制。Dynamic mechanical tests of the C/SiC composites with three different volume fractions of short carbon fiber （16%, 21%, 24.8%） at room temperature were carried out by the split Hopkinson pressure bar （SHPB）, and the destructive interface part of the specimen was scanned by using scanning electron microscopy （SEM）. Experimental results show that the dynamic uniaxial compressive strength of the C/SiC composites increases with the increasing of the strain rate, which shows a strong strain rate effect. There are many fibers pulled out from the fracture surfaces of each specimen of the C/SiC composites. With the increase of short carbon fiber volume fractions, the number of the fibers pulled out in the fracture obviously increases, and the fiber＇s length is relatively longer, which shows that the combination of short cut carbon fiber and silicon carbide matrix is closely related, and the effect of toughening is also ideal. It can be inferred that the fiber pull-out is the main energy absorption and toughening mechanism of C/SiC ceramic matrix composites.

关 键 词：短切碳纤维 体积含量 陶瓷基复合材料 分离式霍普金森压杆 扫描电子显微镜 

分 类 号：TB332[一般工业技术—材料科学与工程]