高频脉冲电流改性SiC/Al复合材料微裂纹愈合机制及组织性能  

Microcrack healing mechanism and microstructure properties of SiC/Al composites modified by high frequency pulse current

作　　者：刘瑞峰[1] 孙晓哲 李文辉[1] 王显 闫杰 LIU Ruifeng;SUN Xiaozhe;LI Wenhui;WANG Xian;YAN Jie(College of Aeronautics and Astronautics,Taiyuan University of Technology,Jinzhong 030600,China;College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China)

机构地区：[1]太原理工大学航空航天学院,晋中030600 [2]太原理工大学材料科学与工程学院,太原030024

出　　处：《航空学报》2023年第22期257-270,共14页Acta Aeronautica et Astronautica Sinica

基　　金：国家自然科学基金(52205405,51775366);山西省基础研究计划(20210302124653);太原理工大学校基金(2022QN151);山西省高等学校科技创新项目(2021L068)。

摘　　要：采用高频脉冲电流技术改性处理轧制态SiC/Al复合材料。首先利用扫描电子显微镜(SEM)和电子背散射衍射仪(EBSD)对不同状态下复合材料的微观组织进行了观察分析,研究了高频脉冲电流作用下微裂纹的动态愈合机制。然后,对复合材料的微纳力学性能及拉伸性能进行了测试。结果表明,高频脉冲电流有效促进了轧制态复合材料发生静态再结晶,使基体晶粒由2.47μm细化至2.02μm,再结晶体积分数由7.43%提高至39.73%,择优取向明显减弱。钻孔-冷轧法预制的微裂纹尖端在高频脉冲电流作用下产生了局部高温,并在压应力的作用下实现了部分愈合。高频脉冲电流处理后,复合材料的拉伸强度和伸长率由347 MPa和12.23%优化至475 MPa和21.65%。研究为拓宽SiC/Al复合材料在航空领域的应用范围奠定了相关理论及实践基础。High-frequency pulsed current technique was employed to modify the microstructure and performance of asrolled SiC/Al composites.The microstructure of the composites in different states was observed and analyzed by Scan⁃ning Elcetron Microscopy(SEM)and Electron Back-Scattered Diffraction(EBSD).The dynamic healing mechanism of microcrack under high frequency pulse current was investigated.Finally,the micro-nano mechanical properties and tensile properties of the composites were tested.Results show that the high frequency pulse current can effectively promote the static recrystallization of the as-rolled composite.Grain size was refined from 2.47μm to 2.02μm,and re⁃crystallization ratio increased from 7.34%to 39.73%,which results in the weakening of the preference orientation.Micro-crack tips prefabricated by the drilling and cold rolling method were partially healed under the action of high tem⁃perature and pressure stress induced by high frequency pulse current.Tensile strength and elongation of the as-rolled composites were optimized from 347 MPa and 12.23%to 475 MPa and 21.65%after high frequency pulse current treatment.This research laid the theoretical and practical foundation for the expansion of SiC/Al composites in aviation field.

关 键 词：SIC/AL复合材料 高频脉冲电流 晶粒细化 微裂纹愈合 再结晶 

分 类 号：V261.3[航空宇航科学与技术—航空宇航制造工程]