(河海大学 机电工程学院，常州 213022)
摘 要: 以BVR2.5 mm2铜导线为研究对象，采用单一变量法对超声波线束焊接进行实验。以焊接振幅、时间、压力为独立变量展开接头力学性能测试和导电性测试，通过接头和断口微观形貌分析超声波线束焊连接机理。结果表明：铜导线接头强度随焊接振幅、时间、压力增大均呈现先增大后减小的趋势，当焊接时间为1100 ms、焊接振幅为40%、焊接压力为0.3 MPa时，各焊接工艺参数均达到临界值，接头抗拉力达到554.8 N。接头电阻随焊接压力增加先减小后增大，当焊接压力为0.3 MPa时，电阻为0.275 mΩ。随着焊接压力的增加，铜导线由边缘向内部逐渐形成稳定冶金结合，先由局部点连接扩展为面连接，然后形成机械嵌合，最终产生原子间键合。在焊接时间、振幅、压力达到临界值时，焊接接头拉伸断口为典型韧性断裂模式，满足强度要求。
关键字: 铜导线；超声波线束焊；力学性能；导电性；微观形貌
（School of Mechanical Engineering, Hohai University , Changzhou 213022, China）
Abstract:The ultrasonic bounding of 2.5 mm2 copper(Cu) cables was conducted through single variable method. The mechanical properties and conductivity of the joint were tested using welding amplitude, time and pressure as independent variables. The connection mechanism of ultrasonic wire bounding was analyzed through the interface micro-morphology and fracture morphology of the joint. The results show that the strength of copper conductor joint increases first and then decreases with the increase of welding amplitude, time and pressure. The tensile strength of the joint reaches 554.8 N, at welding time of 1100 ms, welding amplitude of 40% and welding pressure 0.3 MPa, and all welding process parameters reach the critical value. The joint resistance decreases first and then increases with the increase of the welding pressure. The resistance is 0.275 mΩ when the welding pressure is 0.3 MPa. The microstructure analysis results show that the welded joint gradually forms a stable bond from the edge to the inside. Firstly, the local point connection is extended to face connection, then the mechanical chimerism is formed, and finally it becomes interatomic bonding. The fracture morphology analysis shows that the maximum tensile strength is ductile fracture and the joint plasticity is good.
Key words: Cu cables; ultrasonic wire bounding; mechanical properties; conductivity; micro- morphology
