Many industrial applications of steel depend on a galvanizing step where the steel sheets are immersed in a liquid Zn bath after production. Due to formation of Fe₂Al₅ dross particles in the galvanizing bath, production has to be stopped after some time to replace the bath with pure liquid Zn. At present, growth simulations of dross particles are based on empirical relations and have only limited validity. For improved control over the formation of Fe₂Al₅ dross particles during galvanizing, a better physics-based understanding of the involved kinetics is required.

In this work, we study the growth of Fe₂Al₅ dross particle facets from atomic level to macro scale via a combination of simulation methods. With first principles density functional theory, the two main input parameters are determined. On the one side, we employ static calculations for the adsorption energies of Fe and Al atoms from liquid Zn onto the Fe₂Al₅ surface. On the other side, the diffusivity of Fe and Al in liquid Zn are obtained from first principles molecular dynamics simulations. These two parameters serve as input for the kinetic Monte Carlo simulations of particle growth, which yield growth velocities as function of Fe and Al content in liquid Zn and temperature. Experimental values for diffusion as well as Fe₂Al₅ dissolution measurements are in excellent agreement with our results and show the strength of our approach.