(color online) Wettability of liquid Al on the hybrid substrate which is made up of the Al sheet (left) and Pb sheet (right). (a) Wetting process of liquid Al, the Al film is placed in the centre of the sheet. In the wetting process, the liquid Al ceaselessly moves along a certain direction, and after 600 ps, the liquid Al completely moves to the Al side. (b) Center-of-mass displacement of liquid Al along the x direction (CMD ) on the Al substrate and hybrid Al–Pb substrate, the dashed line in the figure represents the central position of the substrates. (c) Contact angles of liquid Al on the Al side and Pb side before the liquid completely moves to the Al side.