The present study focuses on interface microstructure and joint formation. AA6061 aluminum alloy (Al) and commercial pure titanium (Ti) joints were welded by ultrasonic spot welding (USW). The welding energy was 1100–3200 J. The Al-Ti joint appearance and interface microstructure were observed mainly via optical microscopy and field emission scanning electron microscopy. Results indicated that a good joint can be achieved only with proper welding energy of 2150 J. No significant intermetallic compound (IMC) was found under all conditions. The high energy barriers of Al-Ti and difficulties in diffusion were the main reasons for the absence of IMC according to kinetic analysis. The heat input is crucial for the material plastic flow and bonding area, which plays an important role in the joint formation.

目前的研究重点是界面微观结构和接头形成。AA6061 铝合金 (Al) 和商用纯钛 (Ti) 接头采用超声波点焊 (USW) 焊接。焊接能量为1100-3200 J。主要通过光学显微镜和场发射扫描电子显微镜观察Al-Ti接头外观和界面微观结构。结果表明，只有在适当的 2150 J 焊接能量下才能获得良好的接头。在所有条件下均未发现显着的金属间化合物 (IMC)。根据动力学分析，Al-Ti 的高能垒和扩散困难是不存在 IMC 的主要原因。热输入对材料塑性流动和粘合区域至关重要，在接头形成中起着重要作用。