SiC纤维预制体结构对SiC_(f)/BN/SiC复合材料致密化和力学性能的影响  

Effect of SiC fiber preforms structure on densification and mechanical properties of SiC_f/BN/SiC composites

作　　者：王梦千 贾林涛 李爱军 彭雨晴[3] WANG Mengqian;JIA Lintao;LI Aijun;PENG Yuqing(Eighth Research Institute of Nuclear Industry,Shanghai 201800,China;Shaoxing Institute of Technology,Shanghai University,Shaoxing 312000,China;School of Materials Science and Enginnering,Shanghai University,Shanghai 200444,China)

机构地区：[1]核工业第八研究所,上海201800 [2]上海大学绍兴研究院,绍兴312000 [3]上海大学材料科学与工程学院,上海200444

出　　处：《复合材料科学与工程》2024年第5期58-65,共8页Composites Science and Engineering

摘　　要：为了研究碳化硅(SiC)纤维预制体的结构对SiC基体的化学气相渗透(CVI)工艺致密化过程的影响,利用模拟计算方法分析了2D叠层、2.5D和3D正交三种编织结构SiC预制体在SiC致密化过程中的孔隙结构演变规律,并采用三氯化硼-氨气-氢气-氮气(BCl_(3)-NH_(3)-H_(2)-N_(2))混合气体和三氯甲基硅烷-氢气-氮气(MTS-H_(2)-N_(2))混合气体作为前驱体,利用CVI致密化工艺制备出三种预制体结构的SiC_(f)/BN/SiC复合材料。结果表明,SiC纤维预制体结构不同,SiC_(f)/BN/SiC复合材料的致密化效率不同,其中2.5D纤维预制体的致密化速率最快,3D正交预制体的致密化速率最慢。致密化120 h后,三种预制体结构的复合材料密度均达到2.3 g/cm~3以上,开孔率为10%左右。三种结构的SiC_(f)/BN/SiC复合材料拉伸强度为130~170 MPa。在层间剪切过程中,2D结构SiC_(f)/BN/SiC复合材料与2.5D结构SiC_(f)/BN/SiC复合材料样品都出现了XY面的纤维剥离现象,而3D结构SiC_(f)/BN/SiC复合材料样品发生了正交Z向纤维的断裂。由此可知,SiC纤维预制体结构影响了所形成复合材料的致密化过程和力学性能。In order to study the effect of silicon carbon(SiC) fiber preform structure on the densification process of SiC matrix by chemical vapor deposition(CVI) process,the pore structure evolution of SiC preform with 2D,2.5D and 3D structures during the densification process was analyzed using simulation method;and SiC_f/BN/SiC composites with three kinds of SiC fiber preform structures were prepared by CVI process using boron trichloride-ammonia-hydrogen-nitrogen(BCl_3-NH_3-H_2-N_2)and trichloromethylsilane-hydrogen(MTS-H_2) gas mixture as precursor.The results show that the densification efficiency of SiC_f/BN/SiC composites varies with SiC fiber preforms structure.The densification rate of 2.5D preform and 3D preform is the fastest and the slowest,respectively.After 120 h,the density of three kinds of structure SiC_f/BN/SiC composites was more than 2.3 g/cm~3 and the porosity was about 10%.The tensile strength of the three kinds of SiC_f/BN/SiC composites was 130~170 MPa.In the process of interlaminar shear,2D SiC_f/BN/SiC composites and 2.5D SiC_f/BN/SiC composites showed fiber stripping in XY plane,while 3D SiC_f/BN/SiC composites showed the highest interlaminar shear strength and the fracture of orthogonal Z-direction fibers occurred.Therefore,the densification process and mechanical properties of the composite were affected by the SiC fiber preform structure.

关 键 词：SIC纤维 预制体结构 SiC基体 CVI 致密化 复合材料 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]