熔融渗硅工艺制备的SiC_(f)/SiC复合材料微观结构与性能  

Microstructure and Properties of SiC_(f)/SiC Composite Fabricated by Melt Infiltration Process

作　　者：刘虎 杨金华 陈子木 郎旭东 焦健 LIU Hu;YANG Jinhua;CHEN Zimu;LANG Xudong;JIAO Jian(National Key Laboratory of Advanced Composites,AECC Beijing Institute of Aeronautical Materials,Beijing 100095;Aviation Key Laboratory of Science and Technology on Advanced Corrosion and Protection for Aviation Material,AECC Beijing Institute of Aeronautical Materials,Beijing 100095;Aviation Key Laboratory of Science and Technology on Materials Testing and Evaluation,AECC Beijing Institute of Aeronautical Materials,Beijing 100095;AECC Hunan Aviation Powerplant Research Institute,Zhuzhou 412002)

机构地区：[1]中国航发北京航空材料研究院先进复合材料国防科技重点实验室,北京100095 [2]中国航发北京航空材料研究院航空材料先进腐蚀与防护航空科技重点实验室,北京100095 [3]中国航发北京航空材料研究院材料检测与评价航空科技重点实验室,北京100095 [4]中国航发湖南动力机械研究所,株洲412002

出　　处：《宇航材料工艺》2020年第6期48-54,共7页Aerospace Materials & Technology

摘　　要：SiC纤维增强SiC陶瓷基复合材料(SiCf/SiC复合材料)在航空发动机热端部件方面具有重要应用。本文以第二代碳化硅纤维为增强材料,采用熔融渗硅工艺制备出SiCf/SiC复合材料,测试复合材料的基本物理性能及常规力学性能,并利用Micro-CT、SEM对试样的微观结构和断面进行了表征分析。结果显示:SiCf/SiC复合材料的体积密度为2.78 g/cm^3,开气孔率小于2.0%,基体较为致密,1200℃时热导率(厚度方向)为14.30 W/(m∙K),室温~1200℃厚度方向和面内方向的线胀率分别为0.59%、0.56%,平均热胀系数分别为5.02×10^-6、4.73×10^-6/K;室温面内拉伸强度典型值为317 MPa,SEM显示试样断面具有明显的纤维拔出效应,弯曲强度和层间拉伸强度典型值分别达794和49 MPa。Silicon carbide fiber reinforced silicon carbide matrix(SiCf/SiC)composite had an important application in hot-section componets in aer engines.SiCf/SiC composite was fabricated by melt infiltration(MI)technique using SiC fibers as reinforcement.Physical and mechanical properties of the composite were evaluated and the microstructure and cross section was studied by Micro-CT and SEM.The results show that the bulk density of SiCf/SiC composite is 2.78 g/cm^3 and the apparent porosity is lower than 2.0%.The transverse thermal conductivity at 1200℃is 14.30 W/(m∙K)for the prepared composite.The linear expansion rates in thickness direction and inplane direction are 0.59%and 0.56%and the average coefficient of thermal expansion are 5.02×10^-6/K and 4.73×10^-6/K,respectively.The representative values of in-plane tensile strength,flexural strength and interlaminar tensile strength of SiCf/SiC composite are 317 MPa,794 MPa and 49 MPa,respectively.It is clearly observed that many fibers are pull out of the ceramic matrix from the SEM image of fracture surface of tensile specimen.

关 键 词：SICF /SiC复合材料 熔融渗硅 力学性能 

分 类 号：TB332[一般工业技术—材料科学与工程]