New insight of Ca element refining grain structure in commercial purity Mg based on the first-principle calculation

The first-principle calculation was used to understand new insight of Ca element refining grain structure in commercial purity Mg. Negative adsorption energy, strong ionic bond and negative shift of partial density of states verify that Ca element is readily adsorbed on the surface of MgO. Combined with analysis of interfacial bonding between Mg2Ca and α-Mg, new insight of Mg2Ca layer formed via Ca adsorption efficiently nucleating α-Mg was proposed. Adsorption of other alkaline earth elements (Be, Sr or Ba) and the crystallographic feature of Be, Mg17Sr2 and Mg17Ba2 along with the experimental results further consolidate new insight of Ca element refining grain structure in commercial purity Mg.