Al_(2)O_(3)界面修饰单向纤维C/C复合材料组织结构及其力学性能  

Organizational structure and mechanical properties of Al_(2)O_(3)interfacially modified unidirectional fiber C/C composites

作　　者：贾建刚[1] 钮超 张真 伏芳杏 潘子康 JIA Jian-gang;NIU Chao;ZHANG Zhen;FU Fang-xing;PAN Zi-kang(School of Materials Science and Engineering,Lanzhou Univ.of Tech.,Lanzhou 730050,China;School of Materials Science and Engineering,Shanghai University,Shanghai200444,China)

机构地区：[1]兰州理工大学材料科学与工程学院,甘肃兰州730050 [2]上海大学材料科学与工程学院,上海200444

出　　处：《兰州理工大学学报》2023年第6期1-8,共8页Journal of Lanzhou University of Technology

基　　金：国家自然科学基金(52162005)。

摘　　要：为了缓解C/C复合材料脆性,利用勃姆石溶胶对单向碳纤维预制体进行处理,在纤维表面制备了Al_(2)O_(3)涂层.使用自制的热梯度化学气相沉积(TG-CVI)设备对预制体进行致密化,得到致密的C/C复合材料.通过高温热处理进一步调节界面的结合强度和基体碳的石墨化程度.利用排水法测试复合材料的密度,万能材料试验机测试其拉伸性能,采用可视化石墨烯片层技术(VGT)对试样进行处理,使用偏光显微镜(PLM)、扫描电子显微镜(SEM)、X-射线衍射(XRD)分别研究复合材料的微观组织、界面和断面形貌、以及物相组成.结果表明:涂覆Al_(2)O_(3)涂层的C/C复合材料在沉积后期转变为粗糙层(RL)织构.经过高温热处理后,碳基体的石墨化程度提高,改变了C/C复合材料的断裂机制.由复合材料最初的脆性断裂向拟延性转变,延伸率提高.C_(f)(Al_(2)O_(3))/C-3样品的峰值应力达到了77.3 MPa,延伸率达到了15%.In order to alleviate the brittleness of C/C composites,the unidirectional carbon fiber preform was treated with Boehm sol,and the Al_(2)O_(3)coating was prepared on the fiber surface.The preform was densified by self-made thermal gradient chemical vapor infiltration(TG-CVI)deposition equipment to obtain a dense C/C composite.The bonding strength of the interface and the graphitization degree of the matrix carbon were further adjusted by high-temperature heat treatment.The density of the composite material was tested by drainage method,while tensile properties were assessed with the universal material testing machine.The sample was treated with the visualization of graphene texture(VGT).The microstructure,interfacial,and cross-sectional morphologies of the composite were studied using polarizing microscope(PLM),scanning electron microscope(SEM),and X-ray diffraction(XRD)to analyze phase composition.The results showed that the C/C composites coated with Al_(2)O_(3)coating transform into rough layer(RL)texture in the late deposition stage.After high-temperature heat treatment,the graphitization degree of the carbon matrix is increased.As a result of this,the fracture mechanism of the C/C composite is significantly changed.The elongation is improved from the initial brittle fracture of the composite to the quasi-ductility.The peak stress of the C_(f)(Al_(2)O_(3))/C-3 sample reached 77.3 MPa,and the elongation reached 15%.

关 键 词：C/C复合材料 氧化铝 界面改性 热解碳基体 组织结构 

分 类 号：TB332[一般工业技术—材料科学与工程]