Effects of vacancies at Al(1 1 1)/6H-SiC(0001) interfaces on deformation behavior: A first-principle study

Abstract This paper presents a systematic study on the effects of point vacancies on the behavior of Al(1 1 1)/6H-SiC(0001) composites interface by using first-principles calculation. The research show that the Al point vacancies near the interface is easy to generate, but the generation of C and Si vacancies is difficult. The Al vacancies near the interface have few effects on the interfacial adhesion, but the C and Si vacancies significantly reduce the adhesion energy between the interfaces. The study of tensile properties shows that the fracture positions are usually not at the interface but the Al side near the interface. the presence of C and Si vacancies significantly enhances the tensile properties of the composites, especially the C and Si vacancies at the interfaces. For SiC/Al composite materials, the tensile strength does not increase with the increase of interfacial adhesion strength. However, the tensile strength is determined by the influence of SiC on the atomic and electronic distribution of few layers of Al atoms near the interface.