The effect of impurities Pb, Bi, and PbO on erosion properties of Lead‐Bismuth Eutectic alloy on Fe3O4 oxide film by first principle calculations

Abstract

The first‐principle calculation was performed to study the effect of impurities Pb, Bi, and PbO on erosion properties of liquid lead‐bismuth eutectic alloy on the metal oxide (Fe3O4) and its surfaces. We found that whether in the bulk or on the surface of Fe3O4 the formation energy by substitution of Fe with Bi is slightly larger than that with Pb substitution and the formation energy by substitution of Fe with PbO is much larger than those with Pb and Bi, indicating that PbO has weaker corrosion potential than Pb/Bi. The calculation results show that a tetrahedral site in Fe3O4 should be the weakest position where Fe3O4 is attacked by these exotic impurities. The corrosion process on the oxide film will be initialized at that position. It can be seen that for the doping case the dissociation energy of Fe atom in the (110) surface has the smallest value, a medium value in (100) surface, and the largest value in (111) surface. Correspondingly, the corrosion resistance of doping Fe3O4 film in (110) surface is the weakest one among these surfaces. For the doping‐free case, the (100) surface has the weakest corrosion resistance. By comparing the doping case with no‐doping case it can be seen that the impurities of Pb, Bi, and PbO will weaken the corrosion resistance of Fe3O4 film further. The doping has a negative impact on the stability of the structure and on the corrosion resistance of Fe3O4 film. From present results, it is also seen that the replacement of Fe in Fe3O4 by multiple impurities is more likely to occur than the replacement of only single impurity.