SiC_(f)/SiC铆钉连接结构双剪性能及失效机理  

Double Shear Performance and Failure Mechanism of SiC_(f)/SiC Rivet Connected Structure

作　　者：汪文君 腾雪峰 梁成瑜 罗潇 李坚 刘小冲[4] 胡晓安 WANG Wen-jun;TENG Xue-feng;LIANG Cheng-yu;LUO Xiao;LI Jian;LIU Xiao-chong;HU Xiao-an(Hunan Aviation Powerplant Research Institute,Aero Engine Corporation of China,Hunan Zhuzhou 412000,China;School of Power and Energy,Nanchang Hangkong University,Nanchang 330063,China;Engineering Research Center of Aero-engine Technology for General Aviation,Ministry of Education,Nanchang 330063,China;School of Materials Science and Engineering,Northwestern Polytechnical University,Xi’an 710072,China)

机构地区：[1]中国航发湖南动力机械研究所,湖南株洲412000 [2]南昌航空大学动力与能源学院,南昌330063 [3]通航涡轮动力技术教育部工程研究中心,南昌330063 [4]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：《失效分析与预防》2024年第5期327-336,共10页Failure Analysis and Prevention

基　　金：国家自然科学基金(52305153);江西省自然科学基金(20232BAB214048);中国航发集团自主创新专项资金项目(ZZCX-2021-025)。

摘　　要：陶瓷基复合材料(CMC)的连接结构设计与强度考核是实现其在航空发动机高温承载部件应用的关键。针对SiC_(f)/SiC陶瓷铆钉连接结构首次开展了陶瓷铆钉在室温、1300℃高温空气环境下的双剪力学性能试验和失效破坏分析,验证了SiC_(f)/SiC铆钉应用于CMC构件连接的可行性。结果表明:高温环境下的SiC_(f)/SiC力学性能有一定程度的退化,与室温相比,高温环境下的陶瓷铆钉剪切刚度、剪切强度有明显降低。SiC_(f)/SiC具有良好的抗高温氧化能力,在陶瓷铆钉断口及内部未发现氧化特征,SiC_(f)/SiC铆钉在剪切载荷下发生脆性断裂,SiC纤维断口为解理面断裂,表现为明显的镜面、台阶、羽状特征,并且高温环境下的台阶、羽状断口特征更为凸显。CMC铆钉的承载能力受宏观承载方向与细观纤维铺层方向夹角的影响:当承载方向与铺层方向一致时,CMC铆钉具有较高的剪切刚度;随着夹角由0°增加到90°,CMC铆钉的剪切刚度逐渐降低。Connection structure design and strength assessment of Ceramic Matrix Composite(CMC)are crucial for its application in high temperature bearing components of aero engines.In this study,for the first time,the double shear performance test and failure analysis of SiC_(f)/SiC ceramic rivet at room temperature and 1300℃air environment were carried out,verifying the feasibility of SiC_(f)/SiC rivets applied to the connection of CMC structures.The results show that the mechanical properties of SiC_(f)/SiC are somewhat diminished at high temperatures.Compared with room temperature conditions,both the shear stiffness and shear strength of ceramic rivet decrease significantly at high temperature.However,SiC_(f)/SiC demonstrates good resistance to high-temperature oxidation,with no signs of oxidation found in the fracture surface and within the specimen.SiC_(f)/SiC rivet suffers brittle fracture under shear load,while SiC fiber fracture is cleavage plane fracture,displaying obvious mirror-like,stepped and feathery features.These stepped and feather fracture characteristics are more prominent at high temperatures.Additionally,the load-bearing capacity of CMC rivets is affected by the angle between the macro load-bearing direction and the mesoscopic fiber layup direction.When the load-bearing direction is aligned with the layup direction,CMC rivets have higher shear stiffness.Besides,as the angle increases from 0°to 90°,the shear stiffness of CMC rivets gradually decreases.

关 键 词：SiC_(f)/SiC 铆钉连接结构 双剪性能 失效机理 高温 

分 类 号：TB332[一般工业技术—材料科学与工程]