The diffusion behaviors at the Cu-Al solid-liquid interface: A molecular dynamics study

•The diffusion depth of Cu atoms presents a linear relationship with system temperatures.•The diffusion rate of Cu atoms diffusion in Al liquid is more than 5 times that of Al atoms diffusion in Cu layers.•The alloy layers are mainly formed by the diffusion of Cu atoms in the Al liquid.•The intermetallic in alloy layers is mainly identified as θ-Al2Cu once solidification by annealing.