Mechanistic investigation of alloying elements Cr, Ni, Ti doping effects on TiC/Fe interfacial properties

The interfacial bonding failure of TiC/γ-Fe has emerged as a critical bottleneck restricting the performance enhancement of composite materials. The formation energy, interfacial adhesion work, electronic properties, and d-band center of both doped and clean interfaces were investigated by first-principles calculations. The results show that the Ti-doped interface exhibits the highest stability, attributed to its lowest formation energy (−0.15 eV) at the TiC/γ-Fe interface. The interfacial adhesive work follows the order: Cr-doped interface (6.53 J/m 2 ) > Ti-doped (6.39 J/m 2 ) > Ni-doped (5.15 J/m 2 ), revealing that the interfacial bonding strength was significantly enhanced by Cr and Ti doping. Electronic structure analysis reveals that Cr-C bond exhibit predominantly covalent characteristics. The bonding strength of the Fe-C bond at the interface was enhanced by Cr doping., while both Cr- and Ti-doped interfaces demonstrate more pronounced charge transfer compared to clean systems, thereby strength of interfacial bonding was enhanced. A significant positive correlation was identified between the d-band center and adhesive work, suggesting that the change of surface d-band center provides an effective pathway to enhance strength of interfacial bonding. The computational results elucidate the fundamental mechanisms the whereby interfacial bonding strength of TiC/γ-Fe was enhanced by Cr and Ti doping, offering both theoretical guidance and effective modulation strategies for researches the interfacial performance of composite materials.