预腐蚀2050-T8铝锂合金多轴疲劳失效行为实验研究  

Experimental Study on Multiaxial Fatigue Failure Behavior of Pre-corroded 2050-T8 Al-Li Alloy

作　　者：蒋旺 吴韬 宋海鹏[1] JIANG Wang;WU Tao;SONG Haipeng(Sino-European Institute of Aviation Engineering,Civil Aviation University of China,Tianjin 300300,China)

机构地区：[1]中国民航大学中欧航空工程师学院,天津300300

出　　处：《有色金属(中英文)》2025年第2期179-186,共8页Nonferrous Metals

基　　金：中央高校基本科研业务费重点项目(3122022102);大学生创新创业训练计划项目(202210059068)。

摘　　要：结合三维数字图像相关(DIC-3D)和扫描电子显微镜(SEM),开展了含点蚀2050-T8铝锂合金在不同腐蚀时长和不同等效应力下的多轴疲劳失效研究。通过应变云图和疲劳损伤严重程度曲线分析了试样疲劳损伤演化,描述宏观裂纹的形核、扩展行为,基于扫描电镜断口分析研究微裂纹的萌生、扩展行为。结果表明,试件的多轴疲劳损伤演化在不同腐蚀时长和不同加载载荷下均存在差异,且宏观裂纹的成核时间、数量、大小、位置也不同(即使相同条件下,也会有所差异)。多数宏观裂纹萌生于蚀坑的底部和侧壁,少数宏观裂纹萌生于蚀坑口部。存在多个微裂纹萌生现象,微裂纹的扩展、合并形成宏观裂纹。In this paper,the multi-axial fatigue failure of pre-corroded 2050-T8 Al-Li alloy were investigated by 3d digital image correlation and scanning electron microscope,under different corrosion durations and different equivalent stresses.The fatigue damage evolution of the specimens was analyzed by combining strain maps and fatigue damage severity curves,which provided a description of the macro-cracking behavior.The micro-crack behavior of the specimens were explored through SEM fracture morphology analysis.The experimental results show that the multiaxial fatigue damage evolution of the specimen is different under different corrosion durations and loading loads,and the nucleation time,number,size,and location of macro cracks are also different(even under identical conditions).Most macro cracks initiate at the bottom and side walls of the corrosion pits,and while a few initiate at the mouth of the corrosion pits.Multiple microcrack initiation were observed,with the expansion and merger of microcracks forming macrocracks.

关 键 词：预腐蚀 铝锂合金 多轴疲劳 损伤演化 裂纹萌生 

分 类 号：TG174.3[金属学及工艺—金属表面处理]