The influence of Mn content on Fe2B properties and its impact at the αZ‐Fe16C2 /Fe2B interface

Fe–B alloy is widely used in the field of wear resistance, and the collaborative performance of their precipitated phases and the matrix is of significant interest. This study utilizes first-principles calculations to investigate the influence of Mn on the thermodynamic and mechanical properties of the Fe2B precipitated phase within Fe–B alloys, as well as the role of Mn in regulating the interface between the matrix αz-Fe16C2 and the Fe2B precipitated phase. The computational results reveal that the formation enthalpy remains negative at varying Mn concentrations. The Poisson's ratio of Fe2B is measured at 0.2245. However, under Mn doping, the Poisson's ratio varies with Mn content, with Fe3Mn5B4 exhibiting the highest Poisson's ratio, reaching 0.3157, representing a remarkable 40.62% increase. Interface performance calculations indicate that the interface energy of αz-Fe16C2/Fe2B is 0.4172 eV/Å2, with an adhesive energy of −0.1984 eV/Å2. Upon Mn doping at the interface, the doped interface energy decreases to −3.5393 eV/Å2, and the doped adhesive energy increases to 1.6975 eV/Å2, significantly enhancing interface binding. In conclusion, Mn has the capacity to improve the ductility of Fe2B and enhance the interface binding between the matrix and the precipitates, consequently increasing the wear resistance of Fe–B alloys.