Al/Cu超声波焊接界面晶粒形貌与断裂机制  

Grain Morphology and Fracture Mechanism of Al/Cu Joints by Ultrasonic Welding

作　　者：柳健 刘龙 方文俊 郭志明 LIU Jian;LIU Long;FANG Wenjun;GUO Zhiming(School of Mechanical and Electrical Engineering,Changsha University,Changsha 410022)

机构地区：[1]长沙学院机电工程学院,长沙410022

出　　处：《机械工程学报》2024年第22期153-164,共12页Journal of Mechanical Engineering

基　　金：国家自然科学基金(12002067);湖南省自然科学基金(2022JJ40523);湖南省教育厅科学研究(21B0763,23A0600,23B0790)资助项目。

摘　　要：针对Al/Cu焊接接头易发生脆性断裂的问题,调整铝板和铜板的结构形式,进行Al/Cu超声波焊接试验研究,探究焊接振幅、焊接时间、焊接能量与峰值功率等焊接参数之间的联系。通过扫描电子显微镜与背向散射电子衍射技术分析不同结构形式下Al/Cu超声波焊接界面晶粒形貌与织构变化。结果表明,焊接能量与峰值频率分别随焊接时间、焊接振幅的增加呈线性增加。在焊接压力与高频微动摩擦作用下,不同结构形式的铜板和铝板实现了固相连接。焊接界面铝的微观组织皆出现了均匀分布的位错,发生了动态再结晶,产生了大量的等轴晶粒,其织构由单元{001}<100>转化为剪切织构单元{111}<110>,织构强度明显减小;而纯铜的微观组织没有形成新的位错,晶粒形貌和尺寸基本没变,织构强度增加。通过拉伸试验可以发现,结构形式的改善可以使断裂模式由Al/Cu超声波焊接区域边缘断裂转为铝板自身断裂,提高了Al/Cu超声波焊接接头的力学性能。Aiming at the brittle fracture of Al/Cu joints by ultrasonic welding,the Al/Cu ultrasonic welding experiments were carried out by adjusting the structural forms of copper and aluminum plates.The relationship among welding parameters such as welding amplitude,welding time,welding energy and peak power is established.The grain morphology and texture of Al/Cu joints by ultrasonic welding are analyzed by scanning electron microscopy(SEM)and electron back scatter diffraction(EBSD).The results showed that the welding energy and peak power increased linearly with the increasing welding time and welding amplitude,respectively.Under the action of welding pressure and high-frequency micro-dynamic friction,the solid phase connection of copper and aluminum plates is realized with different structural forms.The uniform distribution of dislocations is showed,dynamic recrystallization occurs,and a large number of equiaxed grain are generated in the microstructure of aluminum along the welding interface.The texture is transformed from the unit{001}<100>to the shear texture unit{111}<110>,and the texture strength decreases significantly.However,new dislocations does not form,the grain morphology and size are basically unchanged,and the texture strength is slightly increased in the microstructure of copper around the welded interface.The tensile test showes that the adjustment of the structure could change the fracture mode from the edge fracture of Al/Cu ultrasonic welding zone to the aluminum plate fracture,and improve the mechanical properties of Al/Cu joint by ultrasonic welding.

关 键 词：超声波焊接 铝/铜 晶粒形貌 断裂机制 

分 类 号：TG136[一般工业技术—材料科学与工程]