“…Aluminium alloy is widely used in modern industrial sectors, such as aerospace [1], shipbuilding [2], automotive [3], and so on., with its good performances, such as low density, good plasticity, and high corrosion resistance [4], etc. Arc technologies, including MIG (Metal Inert Gas Arc Welding) [5] and PAW (Plasma Arc Welding) [6], etc., are widely applied to welding aluminium alloy by industry due to their outstanding benefits, including high efficiency and flexibility, etc. During aluminium alloy welding, the metal droplets are subjected to the effects of multi-physics fields and thus have different thermodynamic behaviours, which are essential to obtain a stable process and a high-quality joint [7].…”