First principle study of tib2 (0001)/γ‐fe (111) interfacial strength and heterogeneous nucleation

Abstract

TiB2/316L stainless steel composites were prepared by selective laser melting (SLM), and the adhesion work, interface energy and electronic structure of TiB2/γ‐Fe interface in TiB2/316L stainless steel composites were investigated to explore the heterogeneous nucleation potential of γ‐ Fe grains on TiB2 particles using first principles. Six interface models composed of three different stacking positions and two different terminations were established. The B‐terminated‐top 2 site interface (“B‐top 2”) was the most stable because of the largest adhesion work, smallest interfacial distances, and smallest interfacial energy. The difference charge density and partial density of states indicated that a large number of strong Fe‐B covalent bonds were formed near the “B‐top 2” interface, which increased the stability of interface. Fracture analysis revealed that the bonding strength of the “B‐top 2” interface was higher than that of the Fe matrix, and it was difficult to fracture at the interface. The interface energy at the Ti‐poor position in the “B‐top 2” interface model was smaller than that of the γ‐Fe/Fe melt, indicating that TiB2 had strong heterogeneous nucleation potency for γ‐Fe.