摘要
综合原料的热物理性能分析和配比设计,实现了C/C复合材料载体孔隙体积的精细控制,采用热压-熔渗两步法在低温条件下制备了具有高致密、低残余Si含量特征的短碳纤维增强C/C-SiC复合材料。系统解析了C/C-SiC复合材料成型过程中的结构演变行为,研究了短纤维增强C/C-SiC复合材料的力学性能和失效机制。结果表明:多孔C/C复合材料载体孔隙的孔径呈双极分布特征,添加芳纶纤维可提高网络孔隙结构的连通性,具有显著的孔隙结构调控作用。SiC基体以网络骨架形态分布于C/C-SiC复合材料内部,与纤维束形成了强界面结合钉扎结构,高含量纤维协同作用下使C/C-SiC复合材料具有优异的综合力学性能,添加芳纶纤维可明显增加复合材料内部裂纹扩展路径,提高C/C-SiC复合材料的断裂韧性。碳纤维的面内各向同性分布及陶瓷相层间均匀分布对C/C-SiC复合材料承载、摩擦稳定性提升均具有积极作用。
One-staged forming of porous C/C composites as well as volume fraction control of pores were realized,based on thermophysical property analysis and proportioning design of raw materials.Short fiber reinforced C/C-SiC composites with high densification and low content of residual Si were prepared by hot-pressing-infiltration two-step method at low temperature.The structural evolution of C/C-SiC composites was analyzed in detail,the mechanical properties as well as failure behaviors were also investigated.Results show that the porous C/C composites present bipolar distribution in pore size,adding aramid fibers is an effective method to improve the connectivity of network pores,exhibiting a significant regulatory effect.Both SiC network skeleton and pinning structure with strong interface between SiC matrix and carbon fiber bundle can entrust the excellent mechanical properties of C/C-SiC composites with high carbon fiber content.In addition,the fracture toughness of C/C-SiC composites can be improved significantly with the addition of aramid fibers,resulting in the increase of crack propagation path.The isotropic distribution of carbon fiber in plane and the uniform distribution of ceramic phase between layers play a positive role in improving the bearing capacity and friction stability of C/C-SiC composites.
作者
刘聪聪
王雅雷
熊翔
叶志勇
刘在栋
刘宇峰
LIU Congcong;WANG Yalei;XIONG Xiang;YE Zhiyong;LIU Zaidong;LIU Yufeng(State Key Laboratory of Powder Metallurgy,Central South University,Changsha 410083,China;Science and Technology of Advanced Functional Composites Laboratory,Aerospace Research Institute of Materials and Processing Technology,Beijing 100076,China)
出处
《材料工程》
EI
CAS
CSCD
北大核心
2022年第7期88-101,共14页
Journal of Materials Engineering
基金
航天动力先进技术湖北省重点实验室开放基金(FY-20Y21-14-11)
湖南省科技成果转化及产业化计划项目(2019GK5070)。
