ABSTRACT

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.

摘要

第一性原理计算用于了解商业纯镁中钙元素细化晶粒结构的新见解。负的吸附能，强的离子键和状态的部分密度的负移证明了Ca元素很容易吸附在MgO的表面上。结合Mg ₂ Ca与α-Mg的界面键合分析，提出了通过Ca吸附有效成核α-Mg形成的Mg ₂ Ca层的新认识。其他碱土元素（Be，Sr或Ba）的吸附以及Be，Mg ₁₇ Sr ₂和Mg ₁₇ Ba ₂的晶体学特征 连同实验结果一起，进一步巩固了商业纯镁中钙元素细化晶粒结构的新见解。