Diffusion Behavior of Aluminum Atoms in Hot Dip RE-Aluminizing

The pure aluminized layer and RE-aluminized layer on industrial pure iron were prepared by hot dip aluminizing method, and the thickness and composition of the layer were investigated by means of scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively. The results showed that the RE was permeated into the alloy layer after hot dip RE-aluminizing and the thickness of the alloy layer increases by about 30% as against hot dip pure aluminizing. The binding energy between the vacancy and aluminum atom was calculated. According to the energy condition of the solute-vacancy complex diffusion, it points out that the solute-vacancy complex diffusion is the main mechanism of aluminum atoms diffusion in hot dip RE-aluminizing and the main reason why the thickness of alloy layer increases after hot dip RE-aluminizing.