5052铝合金高频微振激光焊接疲劳性能及损伤行为  

Fatigue Properties and Fracture Behavior of 5052 Aluminum Alloys Welded by High Frequency Micro-Vibration Laser

作　　者：张巍 卢庆华[1,2] 任新怀 白永真 金杰文 欧徉伶 Zhang Wei;Lu Qinghua;Ren Xinhuai;Bai Yongzhen;Jin Jiewen;Ou Yangling(College of Materials Engineering,Shanghai University of Engineering Science,Shanghai 201620,China;Shanghai Research and Development Center for Key Technologies of Ultra-Intense Laser Processing,Shanghai University of Engineering Science,Shanghai 201620,China)

机构地区：[1]上海工程技术大学材料工程学院,上海201620 [2]上海工程技术大学上海市高强激光智能加工装备关键技术产学研开发中心,上海201620

出　　处：《中国激光》2019年第3期107-113,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(51605276);上海工程技术大学研究-生科研创新专项(17KY0503)

摘　　要：采用光纤激光器对5 mm厚的5052铝合金进行振动焊接,研究其接头组织、残余应力对拉伸性能和疲劳性能的影响。研究结果表明,振动焊接的焊缝组织柱状晶数量明显减少,组织较常规焊缝更均匀细密。采用合适的振动频率与振动加速度,焊缝残余应力可低至140 MPa,而常规焊接焊缝的残余应力高达335 MPa。在应力比为0.1的拉-拉疲劳条件下,母材和接头的条件疲劳极限分别为160 MPa和120 MPa。疲劳源区位于表面缺陷处,裂纹以穿晶形式扩展,大量疲劳条带及二次裂纹产生于断口处。The vibration welding test of a 5 mm thick 5052 aluminum alloy is carried out by a fiber laser.The influences of joint microstructure and residual stress on the tensile properties and fatigue properties are studied.The research results show that the number of columnar crystals in the weld microstructure after vibration welding is significantly reduced,and the microstructure is more uniform and finer than that of an ordinary weld.Under the suitable vibration frequency and vibration acceleration,the residual stress of weld is decreased to 140 MPa,while that of an ordinary weld is up to 335 MPa.Under the tension-tension fatigue condition with a stress ratio of 0.1,the conditional fatigue limits of the base metal and joints are 160 MPa and 120 MPa,respectively.The fatigue source is located in the surface defects and the cracks propagate in a transgranular way.A large number of fatigue striations and secondary cracks are formed in the fractures.

关 键 词：激光光学 激光材料加工 机械振动 焊缝组织 残余应力 疲劳性能 

分 类 号：TG456.7[金属学及工艺—焊接]