Elemental Doping-Induced Bonding Modulation at VC/Fe Interfaces

Multicomponent wear-resistant ferroalloys are indispensable in mining, metallurgy, power generation, construction materials, and machinery manufacturing, with their wear resistance largely governed by the distribution and stability of carbides. However, under severe service conditions, carbides can readily detach from the matrix, thereby limiting the overall lifetime of the alloy. Moreover, the segregation behavior of alloying elements at the matrix-carbide interface, which is critical to interfacial bonding strength and system stability, remains insufficiently understood. Herein, using vanadium carbide (VC) as a case study, we systematically investigate the influence of doping elements on the stability of the γ-Fe/VC interface in Fe-based alloys by means of first-principles calculations. Two representative γ-Fe/VC interface configurations, namely the top-site and 4-fold configurations, have been investigated. The results confirm the top-site as the more stable configuration. Using this model, we systematically evaluated the effects of Cr, Mn, Mo, Ni, Si, and Ti dopants on interfacial stability. Mo, Ni, and Si preferentially segregate to the γ-Fe side, with Mo exhibiting the strongest stabilizing effect. While Cr and Mn segregate at the interface with limited strengthening effects, Ti exhibits a strong carbide-forming tendency, strengthening atomic-scale bonding. These findings advance our understanding of how alloying elements segregate at the interface and provide theoretical guidance for the design of next-generation multicomponent ferroalloys with improved performance.