超声-电阻复合焊接方法及界面行为

Investigation on the interfacial behavior of hybrid ultrasonic resistance welding

有色金属微型零件超声焊接时,由于焊头面积小,输入焊接区域能量少,界面有效连接面积不足,影响焊接接头的力学性能.针对这一问题,结合超声焊接与电阻焊的特点,研制了超声-电阻复合焊接系统.对铜、铝异种金属进行了超声-电阻复合焊接工艺试验,并与相同工艺条件下的超声焊接进行了对比.结果表明,电流对超声能的输出有促进作用,使换能器的峰值功率有明显的增加;超声使焊接起始阶段界面接触电阻迅速减小并消失;在复合能量的作用下,输入焊接区域总能量有较大提高,焊接区域温度和加热速率显著增加.

It is difficult for ultrasonic welding( USW) to be applied in the joining of miniature work pieces. This challenge results from the area of the weld tip,which limits the ultrasonic power delivered to the weld zone. A new hybrid welding technique,the hybrid ultrasonic resistance welding( HURW)technique,is proposed to contribute further to the improvement of ultrasonic welding quality. In the HURW,a synergic effect is obtained from the two different kinds of welding energy,which takes advantage of the beneficial aspects of each process and minimizes the shortcomings of each other. HURW of 6061 aluminum alloy to pure copper is investigated via comparison with the USW process under the same welding condition. Experimental results show that in HURW,the peak power of ultrasonic vibration increases significantly,and more energy is delivered into the weld zone due to the resistance welding current. As a result,the peak temperature and the heating rate of the interface increase remarkably. However,because of the ultrasonic vibration,the interface contact resistance decreases and disappears rapidly at the initial stage of the process. This will minimize the resistance heat.