First-Principles Study on the Structural Stability and Segregation Behavior of γ-Fe/Cr2N Interface with Alloying Additives M (M = Mn, V, Ti, Mo, and Ni)

This study investigated the structural stability and electrochemical properties of alloying additives M (M = Mn, V, Ti, Mo, or Ni) at the gamma-Fe(111)/Cr2N(0001) interface by the first-principles method. Results indicated that V and Ti were easily segregated at the gamma-Fe(111)/Cr2N(0001) interface and enhanced interfacial adhesive strength. By contrast, Ni and Mo were difficult to segregate at the gamma-Fe(111)/Cr2N(0001) interface. Moreover, the results of the work function demonstrated that alloying additives Mn reduced local electrochemical corrosion behavior of the gamma-Fe(111)/Cr2N(0001) interface by cutting down Volta potential difference (VPD) between clean gamma-Fe(111) and Cr2N(0001), while alloying additives V, Ti, Mo, and Ni at the gamma-Fe(111)/Cr2N(0001) interface magnified VPD between clean gamma-Fe(111) and Cr2N(0001), which were low-potential sites that usually serve as local attack initiation points.