不同硼源BN界面SiC_(f)/SiC复合材料的工艺性能研究  

Process and Properties of SiC_(f)/SiC Composites with BN Interfaces of Different Boron Sources

作　　者：李楚星 余金山[1] 王洪磊[1] 周新贵[1] LI Chuxing;YU Jinshan;WANG Honglei;ZHOU Xingui(Science and Technology on Advanced Ceramic Fibers and Composites Laboratory,National University of Defense Technology,Changsha 410073,Hunan,China)

机构地区：[1]国防科技大学新型陶瓷纤维及其复合材料重点实验室,湖南长沙410073

出　　处：《陶瓷学报》2022年第2期236-246,共11页Journal of Ceramics

基　　金：湖南省自然科学基金(2020JJ4467)。

摘　　要：连续SiC纤维增强SiC基复合材料(SiC_(f)/SiC)具有强度高、模量高、耐高温、抗氧化等优良性能,是航空航天领域极具潜力的高温结构材料。界面相是SiC_(f)/SiC复合材料极其重要的组成部分,具有保护纤维、承受载荷、传递应力等功能,特别是BN界面可有效提高SiC_(f)/SiC复合材料的力学性能。采用硼吖嗪和BCl3两种硼源,先通过化学气相沉积(CVD)工艺分别制备了BN界面层;再通过化学气相渗透(CVI)工艺沉积碳制备了SiC_(f)/C复合材料中间体;最后,通过气相渗硅工艺(VSI)制备SiC_(f)/SiC复合材料。通过红外光谱、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、纳米压痕、纳米CT等手段研究了不同硼源制备BN界面的形貌、结构及其对复合材料性能的影响,探索了VSI工艺前后复合材料性能与结构的关系。所得SiC_(f)/SiC复合材料的弯曲强度最高为294.66 MPa,其孔隙率为1.65%,断裂韧性为14.59 MPa·m^(1/2)。Continuous silicon carbide fiber reinforced silicon carbide matrix composites(SiC_(f)/SiC)are promising structure materials for high-temperature aerospace applications,due to their excellent properties such as high strength,high modulus,high temperature resistance and strong oxidation resistance.Interface layer phase as an extremely important part of composites has the function of protecting the fibers,bearing load,transferring the stress and so on.Especially,the insertion of boron nitride interface layers can effectively enhance the mechanical properties of SiC_(f)/SiC composites.Two boron sources,borazole and BCl3,were used to produce the BN interface layer by using CVD process,while pyrolytic carbon was deposited by using CVI process to prepare SiC_(f)/C and then the SiC_(f)/SiC composites were fabricated by using VSI process.Fourier transform infrared(FTIR)spectroscopy,SEM,TEM,nano indentation and nano CT were used to study morphologies and structures of the BN interface layers.The effects of the interface layers on properties of the composites and the relationship between properties and structures of composites before and after the VSI process were evaluated.Bending strength of the SiC_(f)/SiC sample is up to 294.66 MPa,while the porosity and fracture toughness are 1.65%and 14.59 MPa·m^(1/2),respectively.

关 键 词：化学气相沉积 BN 界面 气相渗硅 SIC 复合材料 

分 类 号：TQ174.75[化学工程—陶瓷工业]