First-principles study on the adhesive properties of Al/TiC interfaces: Revisited

Abstract

The interfacial adhesion and separation of Al/TiC interfaces are investigated using the first-principles methods based on density functional theory. The adhesive energies of Al/TiC interfaces predicted by quasiharmonic approach are almost unaltered with temperature (0–800K). However, the wetting experiments show that the adhesive energy increases with temperature (973–1273K). In order to clarify these different results, typical structural models for (100) and (111) Al/TiC interfaces are constructed. For (100) Al/TiC interfaces, the adhesive energies are about 1J/m2 for 5Al/4TiC-C, 5Al/4TiC-Ti, 4Al/5TiC-C and 4Al/5TiC-Ti interfaces, that are smaller than 1Al/1TiC-C. For (111) Al/TiC interfaces, the adhesive energies of C terminated interfaces are larger than that of Ti terminated interfaces. But, the most stable interface structure is AlB stacking for both Ti and C terminations. And the adhesion of AlA stacking is the weakest. Furthermore, the difference charge density and density of states are presented to understand the nature of the different interfacial adhesion. Finally, in order to fit the experimental results, it is suspected that the 1Al/1TiC interface may transform to 5Al/4TiC, 4Al/5TiC and Ti-AlA interfaces with the increasing temperature (973–1273K).