锂电池Cu/Al极耳超声波焊接接头组织与性能

对厚为0.3 mm的Cu/Al箔片进行超声波焊接,通过扫描电镜(SEM)、3D景深显微分析和显微硬度仪等研究焊件接头的显微组织,测试焊接接头的硬度、剥离力及剪切力。结果表明:随焊接能量增大,接头剥离力和剪切力也增大,铝侧至铜侧硬度上升,焊接能量为600 J时,接头剥离力和剪切力达最大值,为145.8、487.8 N,焊接能量继续增大,接头剥离力和剪切力减小。焊接能量为300、750 J时,界面易产生孔洞缺陷,其是接头力学性能下降的主要原因。

Microstructure and properties of Cu/Al tab for lithium battery prepared by ultrasonic welding

0.3 mm thick Cu/Al foil was welded by ultrasonic welding.The microstructure of welded joint was studied by scanning electron microscopy(SEM),and 3 D depth of field micro analysis and micro-hardness tester.The hardness,peeling force and shearing force of welded joint were tested.The results show that with the increase of welding energy,the peeling force and shearing force of welded joint increase,and the hardness from the aluminum side to the copper side shows an increasing trend.When the welding energy is 600 J,the maximum value of peeling force and shearing force are 145.8 N and 487.8 N respectively.The welding energy continues to increase,and the peeling force and shearing force of welded joint decrease accordingly.When the welding energy are 300 J and 750 J,void defects is prone to form at the interface,which are the main reason for the decrease of the mechanical properties of welded joint.