Effects of ultrasonic vibration on resistance spot welding of transformation induced plasticity steel 780 to aluminum alloy AA6061
Effects of ultrasonic vibration on resistance spot welding of transformation induced plasticity steel 780 to aluminum alloy AA6061
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DOI：
10.1016/j.matdes.2019.108053
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发表时间：
2019-11
影响因子：
8.4
通讯作者：
U. Shah;Xun Liu
中科院分区：
文献类型：
--
作者：
U. Shah;Xun Liu
将高频超声振动有效地集成到电阻点焊(RSW)过程中，采用一种新的连接技术--超声电阻点焊(URW)，将780钢与铝合金Al 6061进行了连接。与传统RSW相比，URW的强度提高了300%，破坏前的位移增加了150%以上。光学显微镜(LOM)和扫描电子显微镜(SEM)观察发现，常规RSW单键合铁焊缝存在裂纹和较宽的界面脱粘区域。在超声振动的辅助下，这些界面裂纹被有效地去除，并形成了厚度约为3微米的AlSingle BondFe金属间化合物层(IMC)。断口的扫描电子显微镜图像显示，超声波消除了RSW焊缝断口中常见的卵方状形貌，这是典型的凝固裂纹。现场高速视频显示，超声振动可以帮助去除表面污染和氧化物，并改善熔融铝在AlSingle BondFe界面上的润湿。
A newly developed joining technique, ultrasonic resistance spot welding (URW), where high frequency ultrasonic vibration is effectively integrated into resistance spot welding (RSW) process, has been applied for joining transformation induced plasticity (TRIP) steel 780 to aluminum alloy Al 6061. Comparing URW with traditional RSW, up to 300% increase in strength and more than 150% increase in displacement to failure is achieved. Light optical microscopy (LOM) and scanning electron microscopy (SEM) revealed cracks and wide interfacial debonded regions in conventional RSW Alsingle bondFe welds. With the assistance of ultrasonic vibrations, these interfacial cracks are effectively removed and a thin Alsingle bondFe intermetallic layer (IMC) of around 3 um thickness is formed. SEM images of the fractured surface revealed that ultrasonic waves eliminated the eggcrate morphology generally observed in RSW welds fractured surface, which is a typical representative of solidification cracking. In situ high speed videos showed that ultrasonic vibration can help break off surface contamination and oxides as well as improving wetting of melted aluminum over the Alsingle bondFe interface.