Regulation of the Interface Binding and Elastic Properties of SiC/Ti via Doping‐Induced Electronic Localization

The interface between metal matrix and reinforcement significantly affects mechanical properties of metal matrix composites (MMCs), but the interplay mechanism among the interface microstructure, the interface binding, and the mechanical properties is still unclear. Herein, the interface microstructure and interface binding of beta-SiC (111)/alpha-Ti (0001) composite are regulated through the introduction of Sc, Y, Mg, Al, Si, Ni, Cu, and Mn dopants. Adhesive work and elastic properties of different doped interfaces are studied by first-principles calculations. It is found that the elastic modulus does not directly relate to the adhesive work. The analysis of the electronic structure reveals that dopants change interface bonding states, which results in the localization of the interface electron distribution and enhances the elastic modulus. However, the lattice distortion induced by the dopants causes a significant decrease in the elastic modulus. Combined with the analysis of the adhesive work and interface electronic and atomic structure, the microscopic mechanism of the dopant-induced electronic localization to regulate elastic properties of SiC/Ti composite is established. The new mechanism is helpful to understand the relationship among the interface microstructure, the interface binding, and the elastic properties, and to design MMCs with improved elastic properties.