SiCf/Si_(3)N_(4)复合材料界面层优化  

Interphase optimization of SiCf/Si_(3)N_(4)composites

作　　者：邓杨芳 陈旭 王童童 范晓孟[3] DENG Yangfang;CHEN Xu;WANG Tongtong;FAN Xiaomeng(AECC Sichuan Gas Turbine Research Institute,Chengdu 610500,China;Xi’an Xinyao Ceramic Composite Materials Co.,Ltd.,Xi’an 710117,China;Science and Technology on Thermostructural Composite Materials Laboratory,Northwestern Polytechnical University,Xi’an,710072,China)

机构地区：[1]中国航发四川燃气涡轮研究院,成都610500 [2]西安鑫垚陶瓷复合材料股份有限公司,西安710117 [3]西北工业大学超高温结构复合材料重点实验室,西安710072

出　　处：《航空材料学报》2023年第3期72-78,共7页Journal of Aeronautical Materials

基　　金：国家科技重大专项(J2019-VI-0014-0129);国家自然科学基金(52072303)。

摘　　要：采用化学气相渗透工艺制备SiC纤维增韧Si_(3)N_(4)基复合材料(SiCf/Si_(3)N_(4)),通过调节BN界面层厚度对其力学性能进行优化,利用透射电镜和扫描电镜对其微结构进行表征,结合有限元分析阐明力学性能演变规律。结果表明:随着BN界面层厚度从290 nm增加到550 nm,复合材料的弯曲强度从(190±39)MPa提高到(317±28)MPa,断裂韧度从(7.3±1.6)MPa·m^(1/2)提高到(14.7±0.5)MPa·m^(1/2),拉伸强度从(89±3)MPa提高到(176±17)MPa;随着BN界面层厚度的增加,纤维所受到的残余应力快速变小,应力失配得到有效缓解,材料表现出更好的力学性能。SiC fiber reinforced Si_(3)N_(4)composites(SiCf/Si_(3)N_(4))were prepared by chemical vapor infiltration,and the mechanical properties were optimized by tailoring the BN interphase thickness.The microstructure was characterized by transmission electron microscope and scanning electron microscope,and the evolution of mechanical properties was revealed by the finite element analysis.The results show that with the increase of BN interphase thickness from 290 to 550 nm,the flexural strength is increased from(190±39)MPa to(317±28)MPa,the fracture toughness is increased from(7.3±1.6)MPa•m^(1/2)to(14.7±0.5)MPa•m^(1/2),and the tensile strength is increased from(89±3)MPa to(176±17)MPa.The residual stress of the fiber decreases rapidly with the increase of BN interphase thickness,and the thermal mismatch is effectively alleviated,which makes the material show better mechanical properties.

关 键 词：承载吸波一体化 陶瓷基复合材料 界面优化 强韧化 

分 类 号：TB323[一般工业技术—材料科学与工程]