AA5052薄板磁脉冲胶焊复合接头动态力学性能研究  

Study on Dynamic Mechanical Properties of AA5052 Sheet Magnetic Pulse Hybrid Adhesive-Welded Joints

作　　者：王绍螺 彭定宸 柳泉潇潇 李光耀[1] 崔俊佳[1] WANG Shao-luo;PENG Ding-chen;LIU Quan-xiao-xiao;LI Guang-yao;CUI Jun-jia(State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University,Changsha 410082,China)

机构地区：[1]湖南大学汽车车身先进设计制造国家重点实验室,长沙410082

出　　处：《精密成形工程》2021年第4期52-60,共9页Journal of Netshape Forming Engineering

基　　金：国家自然科学基金(51975202);湖南省自然科学基金(2019JJ30005)。

摘　　要：目的研究AA5052铝合金薄板在高速冲击载荷下的磁脉冲胶焊复合接头的动态力学性能,探究不同载荷速率对该胶焊复合接头力学和失效行为的影响规律。方法利用磁脉冲焊接系统成功制备了胶焊复合连接试件。采用万能拉伸试验机、高速拉伸试验系统,结合全场应变测量系统,获得胶焊复合接头的力学性能规律,以及渐进失效过程和搭接区应变变化。通过扫描电镜观察焊缝断口,对其显微形貌进行表征。结果当剪切速率从2 mm/min提升到10 m/s时,接头的峰值载荷从6086.5 N增大到6592.5 N,吸收的能量从41.1 J增大到96.4 J。相比于2 mm/min准静态剪切断口,1 m/s高速剪切断口中等轴韧窝和胶粘剂薄层的比例均提高。当剪切速率在1 m/s以下时,接头发生胶层和焊缝断裂失效;当剪切速率在1 m/s以上时,胶层和焊缝得到的强化程度高于母材,胶层开裂程度减小,接头搭接区的刚度提高,所以拉伸端母材发生严重的颈缩直至断裂失效。结论随着剪切速率的增加,接头的峰值载荷和吸收能量均增大,胶层的开裂程度减小,失效形式由焊缝和胶层断裂转变为母材断裂。Dynamic mechanical properties of AA5052 aluminum alloy sheet magnetic pulse hybrid adhesive-welded joints under high-speed impact load were studied.The influence laws of different loading rates on the mechanical and failure behavior of the hybrid joints were explored.The adhesive-welded hybrid specimens were successfully prepared by the magnetic pulse welding system.Mechanical properties,progressive failure process and strain change in the lap zone of the hybrid joints were obtained by universal tensile testing machine,high-speed tensile testing system and full field strain measurement system.The weld fracture was observed by scanning electron microscopy,and its microscopic morphology was characterized.Results showed that when the loading rate was increased from 2 mm/min to 10 m/s,the peak shear load of the joint improved from 6086.5 N to 6592.5 N,and the absorbed energy increased from 41.1 J to 96.4 J.Compared with the 2 mm/min quasi-static shear fracture,the proportion of the equiaxed dimples and the thin adhesive layer of the 1 m/s high-speed shear fracture was increased.When the shearing rate was below 1 m/s,the failure mode of the joint was the fracture of the adhesive layer and the weld.However,when the shearing rate was above 1 m/s,the adhesive layer and weld were strengthened more than the base metal;the cracking degree of the adhesive layer was decreased,and the stiffness of the joint lap area was improved,resulting in severe necking until the fracture of the base metal aluminum sheet.As the shearing rate increased,the peak load and absorbed energy of the hybrid joint increased;the cracking degree of the adhesive layer was reduced,and the failure mode changed from the frac-ture of the weld and the adhesive layer to the fracture of the base material.

关 键 词：AA5052铝合金薄板 磁脉冲胶焊复合接头 动态力学性能 微观形貌 

分 类 号：TG391[金属学及工艺—金属压力加工] TG456