焊接能量对铝/铜超声波焊接接头显微组织的影响

进行了1 mm厚铝/铜异种金属超声波焊接试验研究,分析了不同焊接能量输入对接头形貌、接合区塑性变形、原子扩散的影响.结果表明,工件在高频振动作用下,连接界面间会发生漩涡状塑性变形,形成局部机械自锁,有助于实现超声波接头的有效连接.焊接能量较小时,结合区域塑性变形量小,局部区域无法形成连接;焊接能量过大时,接合区域会出现空穴.SEM和EDS分析表明,能量过高时(2000 J),接触界面区域会形成薄金属间化合物层,其主要成分为Al₄Cu₉.

Effect of welding energy on microstructures of the Al/Cu joints obtained by ultrasonic welding

An experimental investigation of ultrasonic welding of 1mm thick 6061 aluminum alloy and pure copper was conducted in this research. Weld appearance,plastic deformation and atomic diffusion in the weld zone under different welding energy input have been investigated. The results showed that swirl-like plastic deformation occurs at the interfaces due to the high-frequency ultrasonic vibration,which led to a mechanical interlocking between materials. The plastic deformation was too small to gain a qualified joint under a lower energy input,while void defect was likely to appear if the energy was excessively high. Moreover,intermetallic compound (IMC) at the interface of the workpieces was also observed through the SEM and EDS analysis. A 0.5 μm-thick IMC layer with the dominant phase of Al₄Cu₉ was found in 2000 J welding energy joint.