C_(f)/Al复合材料复合编织结构T型件弯曲性能  

Bending properties of composite braided structure T⁃shaped parts of C_(f)/Al composite material

作　　者：李志文 蔡长春 余欢 徐志锋 王振军 李荣幸 LI Zhiwen;CAI Changchun;YU Huan;XU Zhifeng;WANG Zhenjun;LI Rongxing(National Defense Key Discipline Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学轻合金加工科学与技术国防重点学科实验室,南昌330063

出　　处：《航空学报》2023年第10期322-336,共15页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(52165018);航空科学基金(2019ZF056013);江西省自然科学基金(20202ACBL204010)。

摘　　要：以航空发动机中典型结构T型件为研究对象,选用三维五向(立板)和叠层缝合(底板)两种结构复合编织了T型件预制体,采用真空压力浸渗法制备了C_(f)/Al复合材料复合编织结构T型件。分别进行了室温和350℃条件下的两点弯曲试验,探究了不同温度下复合材料T型件的弯曲性能,分析了T型件微观组织特征、弯曲载荷-位移曲线、破坏形貌及其失效机制。结果表明:C_(f)/Al复合材料三维复合编织结构T型件微观组织无明显缺陷,且两种编织结构缝合较完整。室温条件下,T型件平均弯曲强度为384.2 MPa;350℃条件下,平均弯曲强度为204.6 MPa。其室温和350℃弯曲载荷-位移曲线呈现非线性特征,且都存在线性弹性阶段、塑性变形阶段、失效卸载阶段。复合材料弯曲失效后,没有碎裂和断裂,仍保持结构的完整性。但由于根部是由两种不同编织结构缝合而成以及根部圆角的存在,容易使根部产生应力集中,以致失效部位集中在根部。Taking the typical structural T-shaped parts of aero-engine as the research object,the preform of T-shaped parts was braided with three-dimensional five-dimensional(vertical plate)and laminated stitched(bottom plate)com⁃posite structures,and the composite braided structure T-shaped parts of C_(f)/Al composite material were formed by vacuum pressure infiltration method.Two-point bending experiments at room temperature and 350℃were carried out to explore the bending properties of composite T-shaped parts at different temperatures,and the microstructure char⁃acteristics,bending load-displacement curves,fracture morphology and failure mechanism of T-shaped parts were analyzed.The results show that there is no obvious defect in the microstructure of three-dimensional composite braided structure T-shaped parts of C_(f)/Al composite material,and the stitching of the two braided structures is com⁃plete.At room temperature,the average bending strength of T-shaped parts is 384.2 MPa and at 350℃,the average bending strength is 204.6 MPa.The bending load-displacement curves at room temperature and 350℃show nonlin⁃ear characteristics,and there are linear elastic stage,plastic deformation stage and failure unloading stage.After the bending failure,there is no fragmentation and fracture,and the structural integrity is still maintained.However,the root is stitched by two different braided structures and the root fillet exists,it is easy to produce stress concentration in the root,so that the failure part is concentrated in the root.

关 键 词：三维编织 C_(f)/Al复合材料 T型件 两点弯曲 弯曲性能 失效机制 

分 类 号：V232.4[航空宇航科学与技术—航空宇航推进理论与工程] TB333[一般工业技术—材料科学与工程]