Effects of alloying elements X (Cr, Mn, Mo, Ni, Si) on the interface stability of TiC (001)/γ-Fe (001) in TiC/316L stainless steel composite formed by selective laser melting: first principles and experiments

TiC/316L stainless steel composite was prepared by selective laser melting (SLM). The effects of alloying elements X (Cr, Mn, Mo, Ni, Si) in 316L stainless steel on the stability of TiC (001)/gamma-Fe (001) interface were calculated by the first principle. The results showed that alloy elements easily replace the Fe atom at the interface, and all of them have the tendency to segregate to the interface. The adhesion work, bond length, interlayer distance, and electronic properties were calculated; it was found that the interface models of Cr4, Mn4, Mo4, Ni1, and Si1 are more conducive to improve the interface bonding strength, and the Cr-, Mn-, and Mo-doped interfaces are more stable than other interfaces. Both X1 and X4 structures represent the doping of an alloy atom but only in different crystallographic sites. Therefore, the introduction of Cr, Mn, Mo, Ni, and Si will promote the heterogeneous nucleation of Fe on TiC and enhance the heterogeneous nucleation potential of TiC and improve the interfacial bonding strength of TiC/316L stainless steel composite.