The model of effective heat of formation in metal-Al binary system proposed by Pretorius et al. was developed based on characteristics of the solid-state reaction at interface to predict the formation of intermetallics during metal ion implantation into Al substrate at elevated temperature. For the Fe, Hf, Mo, Nb, Ni, Ta and Zr ion implantation with the ion energy of 50-140 keV under the ion current density of 10-60 lA/cm 2 into Al substrate to the implantation dose of 10 17 -10 18 ions/cm 2 at the elevated temperature ranging from 300 ยฐC to 600 ยฐC, the model of effective heat of formation predicted the formation of intermetallics Al 13 Fe 4 , HfAl 3 , MoAl 12 , NbAl 3 , NiAl 3 , TaAl 3 and ZrAl 3 , which were consistent with the experimental results. Taking the kinetic factors and the limitation of thermodynamic data into account, the model of effective heat of formation explained the formation of metastable intermetallics Cr 14 Al 86 at the lower temperature of 400 ยฐC and of the stable intermetallics Cr 2 Al 13 at the higher temperature of 510 ยฐC, and the formation of simple intermetallics VAl 3 relative to complex intermetallics V 4 Al 23 , VAl 7 , and VAl 10 , for the Cr and V ion implantation into Al substrate, respectively, at the elevated temperature up to 510 ยฐC.