Effects of active elements on adhesion of the Al2O3/Fe interface: A first principles calculation

The poor wettability of alumina surface greatly limits the interface binding between alumina and iron in alumina reinforced iron matrix composites. In this work, the active elements (Ti and Ni) additives are introduced into the interface to enhance the adhesion of the interface, and the activation mechanism is studied. Through the analysis of the embedding ability of activating elements Ti or Ni in Al2O3/Fe interface and their influence on adhesion of interfaces, it is revealed that Ti is prone to segregation at the interface and has a great improvement on the strength and stability of interface binding. However, Ni hardly enhances interface interaction and even causes interface deterioration. Electron structures analysis shows that 4 s, 3p, 3d coupling of Ti results in more electrons involved in the interface interaction, and the formation of Ti-Fe and Ti-O bonds essentially determines the increase of the work of adhesion. The activation mechanism of Ti and Ni well explains the experimentally reported different existence forms and action modes of Ti and Ni.