Atomic-Scale Mechanism of Titanium-Induced Frictional Removal of Silicon Carbide: A Molecular Dynamics Study

The atomic-scale mechanism of the titanium-induced frictional removal of 3C-SiC remains insufficiently understood, particularly regarding the role of interfacial chemical interactions in material removal. In this study, molecular dynamics (MD) simulations were performed to systematically investigate the interfacial reactions, atomic migration, and structural evolution during titanium friction on SiC surfaces. The results demonstrate that Ti atoms diffuse into the SiC lattice, while Si and C atoms migrate toward the Ti layer, leading to the formation and evolution of Ti-Si and Ti-C bonds at the friction interface. These tribochemical interactions disrupt the stable Si-C bonding network, promote atomic rearrangement, and accelerate lattice amorphization, thereby facilitating friction-induced material removal. Compared with the Si-terminated surface, the C-terminated surface exhibits stronger Ti-C chemical affinity, resulting in enhanced interfacial diffusion, more severe amorphization, and pronounced graphitization. Moreover, increasing the indentation depth mainly enhances mechanical deformation, whereas higher sliding velocity and temperature promote atomic activation and interfacial chemical reactions. This work reveals the synergistic mechanism of tribochemical bonding and structural transformation during titanium-assisted SiC removal, providing fundamental insights and theoretical guidance for the development of high-efficiency and low-damage ultra-precision machining technologies for SiC.