Characterisation of magnesium oxide and its interface with α-Mg in Mg–Al-based alloys

Heterogeneous nucleation in Mg–Zr alloy under die casting condition

“…This implies that no specific plane is priory favoured during nucleation and Zr nuclei may not need to follow a strict orientation relationship. In other words, every plane is simultaneously capable of acting as the effective nucleation plane resulting in a different nucleation mechanism in Mg-Zr system in contrast to the well-known nucleation mechanism, such as TiB 2 in Al and MgO in Mg, where these grains only nucleate on the 0001 TiB 2 ( ) and (111) MgO planes of the faceted TiB 2 and MgO particles [7,8], respectively. In order to confirm this assumption, the convincing evidences are required to demonstrate the existence of different types matching interfaces with various orientations in Mg-Zr system.…”

First-principles calculation of Mg/MgO interfacial free energies

“…Even though HRTEM measurements [27] show that interfaces are not atomically flat over large distances, over the distances spanned by our computational cells, this is a valid approximation. The interfacial free energy γ(T) can be obtained as a function of temperature using a slab technique [28].…”

First-principles study of Mg(0001)/MgO(1-11) interfaces

“…The nanosized MgO particles have been observed as a potent substrate for heterogeneous nucleation of Mg melt. 6 7 Obviously, it is very important that the Mg/MgO interfacial characteristic was explored to shed light on the heterogeneous nucleation and grain refinement process of Mg grain. The first-principles studies based on density-functional theory (DFT), which not only can give insight into the detailed atomic and electronic structures of the interface but also can ascertain the interface stability and the interfacial structure, have already been successfully applied in the metal/compound interface.…”

“…[8][9][10][11][12][13] In the case of Mg/MgO interface, a previous paper described the first-principles calculational study of the Mg/MgO interface with an orientation relationship of Mg (0001) Mg [011] MgO (111) MgO . 14 The authors analyzed the contradiction between the experimental results for the work of adhesion of molten Mg on MgO(111) surface and the calculated value of O-terminated Mg/MgO interface, and suggested that an important reason for this discrepancy could simply be attributed to the Mg atom deposition on the O-terminated MgO(111) surface without considering the chemical potential dependence of the stability of Mg-terminated and O-terminated MgO (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11) surface. This investigation on Mg/MgO interface is theoretically inadequate because the O-terminated interface may not be the reasonable Mg/MgO interface configuration and there is a need to systematically ascertain the interfacial characteristics of Mg-terminated and O-terminated Mg/MgO interfaces based on the effect of chemical potential dependence on MgO surface.…”