摘要
对航空铝合金2A12宽板搭接件进行了基准疲劳试验、预腐蚀疲劳试验、腐蚀-疲劳交替试验,观察搭接件内部腐蚀情况、断口情况;对比分析了三种不同情况的下的结果形成原因;从腐蚀产物、腐蚀形态、裂纹形成位置、能谱分析等方面对试验件进行微观对比分析。结果表明:预腐蚀试验后,试验件疲劳寿命下降明显,腐蚀—疲劳交替试验疲劳寿命最低,腐蚀—疲劳交替试验对试验件的疲劳性能影响较大;预腐蚀试验后,搭接处缝隙内有明显的腐蚀痕迹存在,缝隙环境加重了缝隙内部的腐蚀;裂纹源为韧性断裂,外表面有脆性特征,也存在解裂、二次裂纹等特征;对于腐蚀—疲劳交替试验搭接件,裂纹在界面腐蚀坑处发展,萌生的裂纹呈解理、沿晶等特征;腐蚀和应力的耦合降低了疲劳寿命。
Experimental data of lap joint specimens of LY12CZ was gained through fatigue test with different condition.The corrosion and fracture morphology was observed and was analyzed the reason of three different cases.The microanalysis of the specimens was made based on corrosion products and corrosion morphology and crack formation location and energy spectrum analysis.The results show that the fatigue life of the pre-corroded specimens declines markedly and the fatigue life of the corrosion-fatigue specimens is lowest.The effect of corrosion-fatigue on the fatigue life is great.The gap of the lap joint has corrosion trace and the gap environment aggravates the corrosion of the cracks inside.The source of crack is ductile fracture and the outside surface has brittle properties and has the feature of disaggregation and secondary crack.The crack develops from the etch pit of the interface,and has the feature of cleavage and intergranular fracture.The coupling of corrosion and stress reduces the fatigue life.
作者
徐丽
郁大照
许振晓
刘琦
XU Li;YU Da-zhao;XU Zhen-xiao;LIU Qi(School of Aeronautical Foundation of Naval Aviation University,Yantai,264001,China)
出处
《强度与环境》
CSCD
2021年第4期52-58,共7页
Structure & Environment Engineering
基金
国家自然科学基金资助项目(51375490)。
关键词
搭接件
疲劳试验
疲劳寿命
微观分析
Lap joint
Fatigue test
Fatigue life
Microscopic analysis
