1561铝合金MIG焊接头的低周疲劳性能研究  

Study on Low Cycle Fatigue Properties of 1561 Aluminum Alloy Welded Joints

作　　者：闫文青[1] 刘东 鄢文泽 王强 巫正俞 YAN Wenqing;LIU Dong;YAN Wenze;WANG Qiang;WU Zhengyu(State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China;Hubei MKJY Technology Co.,Ltd.,Ezhou 438070,China)

机构地区：[1]武汉科技大学耐火材料与冶金国家重点实验室,湖北武汉430081 [2]湖北美科精毅科技有限公司,湖北鄂州438070

出　　处：《热加工工艺》2023年第5期127-130,共4页Hot Working Technology

基　　金：国家自然科学基金资助项目(51575408);企业合作项目(2019H10179)。

摘　　要：采用金属极惰性气体保护焊(MIG)制备了1561铝合金对接接头。在室温下,应变比为0.1和循环频率为3 Hz时进行了焊接接头的低周疲劳试验。讨论了应变幅对疲劳寿命的影响,分析了疲劳断口的特征。结果表明,该焊接接头的低周疲劳寿命随着应变幅的增加而降低。疲劳断口分为3个区域,即裂纹源区、裂纹稳定扩展区和瞬断区。疲劳寿命主要取决于裂纹稳定扩展区的大小,近表面气孔和脆性金属间化合物相是主要的裂纹形核源,因此控制焊接接头中气孔和脆性金属间化合物的形成是提高疲劳寿命的关键。1561 aluminum alloy butt welded joints were prepared by metal arc gas welding.At room temperature,the low cycle fatigue experiments were performed with the strain ratio of 0.1 and the cyclic frequency of 3 Hz.The effects of the strain amplitude on the fatigue life were discussed.The fatigue fracture features were analyzed.The results show that the low cycle fatigue life of the welded joints decreases with the increase of strain amplitude.The fatigue fracture is divided to three regions of crack initiation zone,crack stable growth zone and transient fracture zone.The fatigue life depends on the area of crack stable growth zone,the blowholes close to the surface and intermetallic compounds are the main crack nucleation sources.Therefore,the control of the formation of blowholes and intermetallic compounds in the welded joints is the key to improve the fatigue life.

关 键 词：1561铝合金 焊接接头 金属极气体保护焊 低周疲劳 疲劳断口 

分 类 号：TG405[金属学及工艺—焊接]