A discussion of La doping on the nucleation of α-Al in Al–Zn–Si coating

Abstract

The addition of trace La significantly affected the properties of the Al–Zn–Si coating. Adding La improved the corrosion resistance of the coating. More importantly, it restrained the nucleation of α-Al dendrites consequently leading to coarser grains. Based on the density functional theory calculations, we found that the doping concentration was important to the spontaneous nucleation of the heterogeneous nucleus in liquid metal, and there should be a transition between homogeneous nucleation and heterogeneous nucleation.