CVI-GSI工艺制备C/C-SiC复合材料的组成结构与力学性能  

Structure and Mechanical Properties of C/C-SiC Composites Prepared by CVI-GSI Processes

作　　者：孙国帅[1] 刘荣军[1] 曹英斌[1] 贺鹏博[1] 龙宪海[1] SUN Guo-shuai;LIU Rong-jun;CAO Ying-bin;HE Peng-bo;LONG Xian-hai(College of Aerospace Science and Engineering,National University of Defense Technology,Changsha 410073 , China)

机构地区：[1]国防科学技术大学航天科学与工程学院,长沙410073

出　　处：《材料工程》2017年第12期58-64,共7页Journal of Materials Engineering

基　　金：国防科学技术大学科研计划项目(JC14-01-01)

摘　　要：采用密度为1.0g/cm^3的C/C素坯,联合化学气相渗透(CVI)和气相渗硅(GSI)2种工艺制备C/C-SiC复合材料,研究CVI C/C-SiC复合材料中间体的密度对CVI-GSI C/C-SiC复合材料物相组成、微观结构及力学性能的影响。结果表明:随着CVI C/C-SiC复合材料中间体密度的增大,CVI-GSI C/C-SiC复合材料C含量增多,残余Si含量减少,SiC含量先增多后减少,CVI-GSI C/C-SiC复合材料的密度先增大后减小;随着CVI C/C-SiC复合材料中间体的密度由1.27g/cm^3增加到1.63g/cm^3时,得到的CVI-GSI C/C-SiC复合材料的力学性能先升高后降低。当CVI C/C-SiC复合材料密度为1.42g/cm^3时,制得的CVI-GSI C/C-SiC复合材料力学性能最好,其弯曲强度为247.50MPa,弯曲模量为25.63GPa,断裂韧度为10.08MPa·m^(1/2)。C/C-SiC composites were prepared by the combined process of chemical vapor infiltration(CVI)and gaseous silicon infiltration(GSI)using C/C green body with the density of1.0g/cm3.Effect of CVI C/C-SiC intermediate composites?density on the phase composition,microstructure and mechanical properties of CVI-GSI C/C-SiC composites was studied.The results show that as the CVI C/C-SiC intermediate composites'density increases,the residual C content increases and residual Si content decreases in the CVI-GSI C/C-SiC composites,the SiC content increases first and then decrea-ses,and the density of CVI-GSI C/C-SiC composites increases first and then decreases;as the CVI C/C-SiC in termediate composites^density is increased from1.27g/cm3to1.63g/cm3,the mechanical properties of CVI-GSI C/C-SiC composites increase at first,which then decrease with the further in-creasing of CVI-C/C-SiC composites?density.Specifically,when the CVI C/C-SiC composites density is1.42g/cm3,the prepared CVI-GSI C/C-SiC composites has the best mechanical properties,with flexure strength,flexure modulus and fracture toughness of247.50MPa,25.63GPa and10.08MPa?m1/2,respectively.

关 键 词：CVI GSI C/C-SIC复合材料 物相组成 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]