纤维热处理对C/C-SiC复合材料断裂韧度的影响  

Influence of Carbon Fiber Heat Treatment on Fracture Toughness of 2D C / C-SiC Composites

作　　者：代吉祥[1] 沙建军[1] 张兆甫 李建[1] 韦志强[1] 

机构地区：[1]大连理工大学工业装备结构分析国家重点实验室,辽宁大连116024

出　　处：《航空材料学报》2014年第2期69-76,共8页Journal of Aeronautical Materials

基　　金：中央高校基本科研业务费专项基金(DUT11ZD(G)01);教育部新世纪人才计划(NCET-11-0052)

摘　　要：对未处理和不同温度(600℃,900℃,1200℃和1500℃)热处理的纤维增强树脂基复合材料(CFRP)进行裂解,获得不同微裂纹和孔隙分布的C/C预制体,用液硅熔渗法(LSI)制备C/C-SiC复合材料。采用单边切口梁法(SENB)测试C/C-SiC复合材料的断裂韧度,分析纤维热处理温度对C/C-SiC复合材料微观形貌和断裂韧度的影响机理。结果表明:对碳纤维进行热处理能够有效改变C/C预制体的裂纹和孔隙分布,通过液Si熔渗可以制备不同微观组织结构的C/C-SiC复合材料,经热处理纤维增强的C/C-SiC复合材料中SiC基体增多,包裹在C纤维表面且分布较为均匀,同时C/C-SiC复合材料的断裂韧度提高,经1200℃热处理的碳纤维增强的C/C-SiC复合材料断裂韧度达到7.9MPa·m1/2,与未处理的相比,断裂韧度提高了53%。In order to investigate the influence of carbon fiber heat treatment on the fracture toughness of 2D C/C-SiC composites via liquid silicon infiltration process, the carbon fiber was heat-treated at temperatures range from 60℃ to 1500℃ under vacuum. The fracture toughness was evaluated using single edge notched beam （SENB） test. The surface morphologies of C/C preform, C/C-SiC composites and the fracture surface were observed using scanning electron microscopy （SEM）. The porosity and density were measured using the Archimedes method. The results indicate that the fracture toughness increases with increasing the heat treatment temperature of carbon fiber. The fracture toughness of composite reinforced with the 1200~C heat-treated fiber is about 7.9MPa ~ m~/2 , which is in- creases by 53% in comparison to that of the untreated fiber reinforced composite. The results of SENB test and structure show that the high fracture toughness in heat treated fiber reinforced composite is attributed to the strong fiber/matrix bonding strength, homogeneous distribution of SiC and high volume fraction of SiC in matrix.

关 键 词：C C-SiC复合材料 热处理 微观结构 断裂韧度 

分 类 号：TB332[一般工业技术—材料科学与工程] V257[航空宇航科学与技术—航空宇航制造工程]