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.