SiC颗粒增强镁基复合材料界面稳定性的第一性原理计算

针对SiC颗粒增强镁基复合材料界面的理论研究较少,大多研究仅停留在表征层面等问题。本文采用第一性原理方法,计算了四种不同SiC(0001)/Mg(0001)界面模型的电荷密度、布局分析和界面分离功。结果表明:对于同种终端的SiC(0001)/Mg(0001)界面模型中,顶位型结构比心位型结构的稳定性好;不同终端的SiC(0001)/Mg(0001)的界面模型中,Si终端结构比C终端结构更加稳定,其中Si终端顶位型结构稳定性最好,其分离功为W_sep=3.297 J/m²,界面间距为d₀=2.651nm。界面的键合方式主要为C-Mg共价键和Mg-Si离子键。

First-Principles Calculation of Interfacial Stability of SiC Particle Reinforced Magnesium Matrix Composites

There are few studies on the interface of SiC particle reinforced magnesium matrix composites. In this paper, the first principles plane wave super soft pseudopotential method based on density functional theory is used to calculate the interface separation work, charge density and layout analysis of four different SiC(0001)/Mg(0001) composites interface models. The results show that for the SiC(0001)/Mg(0001) interface model with the same terminal, the stability of the top structure is better than that of the center structure. In the SiC(0001)/Mg(0001) interface model with different terminals, the Si terminal structure is more stable than the C terminal structure, and the top structure of the Si terminal is the most stable. The separation work of the Si terminal is W_sep=3.297 J/m², and the interfacial spacing is d₀= 2.651 nm. In the SiC(0001)/Mg(0001) interface structure at the top of Si terminal, the interface is mainly composed of C-Mg covalent bond and Mg-Si ionic bond.