摘要
以聚丙烯腈(PAN)基炭纤维(Cf)针刺整体毡为预制体,用化学气相渗透(CVI)法制备炭纤维增强炭基体(C/C)的多孔坯体,采用熔融渗硅(MSI)法制备C/C-SiC复合材料,研究了渗剂中添加Al对复合材料组织结构和力学性能的影响。结果表明:C/C坯体反应溶渗硅后复合材料的物相组成为SiC相、C相及残留Si相。随着渗剂中Al量的增加,材料组成相中的Al相也增加而其它相减少;SiC主要分布在炭纤维周围,残留Si相分布在远离炭纤维处,而此处几乎不含Al;当渗剂中Al量由0增加到10%时,复合材料的抗弯强度由116.7 MPa增加到175.4 MPa,提高了50.3%,断裂韧性由5.8 MPa.m1/2增加到8.6 MPa.m1/2,提高了48.2%。Al相的存在使复合材料基体出现韧性断裂的特征。
C/C-SiC composites were fabricated by molten silicon infiltration （MSI） to C/C preforms prepared by chemical vapor infiltration （CVI）. The influences of adding Al in molten Si infiltrating agent on the microstructure and mechanical properties of the composites was studied. The results show that the composites fabricated by infiltrating Si into C/C preforms contain SiC, C and residual Si phases. With the increasing of the amount of adding Al in the agent, the amount of Al phase in the composites increases and the amounts of other phases such as SiC and Si phase decrease. SiC phase distributes around the carbon fiber, and Si phase exists far away from the carbon fiber where there is nearly no Al phase. The bending strength and the fracture toughness increase with the increase of the amount of adding Al. When the amount of Al increases from 0 to 10%, the bending strength increases from 116.7 MPa to 175.4 MPa and the fracture toughness from 5.8 MPa·m^1/2 to 8. 6 MPa·m^1/2 , that is, by 50.3% and 48.2% respectively. The Al phase makes the fracture mechanism of the composite become toughness fracture.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2006年第5期34-38,共5页
Acta Materiae Compositae Sinica
基金
国家自然科学基金项目(50472078)
高校博士点基金项目(20040533006)
作者简介
通讯作者：易茂中，教授，博士生导师，主要从事C／C、C／C-陶瓷复合材料、材料摩擦学、材料表面工程方面的研究E-mail：yimaozhong@126．com
