First Principles Study of Adsorption of Hydrogen on Typical Alloying Elements and Inclusions in Molten 2219 Al Alloy

To better understand the effect of the components of molten 2219 Al alloy on the hydrogen content dissolved in it, the H adsorption on various positions of alloying element clusters of Cu, Mn and Al, as well as the inclusion of Al(2)O(3), MgO and Al(4)C(3), were investigated by means of first principles calculation, and the thermodynamic stability of H adsorbed on each possible site was also studied on the basis of formation energy. Results show that the interaction between Al, MgO, Al(4)C(3) and H atoms is mainly repulsive and energetically unfavorable; a favorable interaction between Cu, Mn, Al(2)O(3) and H atoms was determined, with H being more likely to be adsorbed on the top of the third atomic layer of Cu(111), the second atomic layer of Mn(111), and the O atom in the third atomic layer of Al(2)O(3), compared with other sites. It was found that alloying elements Cu and Mn and including Al(2)O(3) may increase the hydrogen adsorption in the molten 2219 Al alloy with Al(2)O(3) being the most sensitive component in this regard.