First Principle Calculation of NbC Precipitation Competition between TiC Particle and Ferrite Matrix

Abstract

The electronic structure, cohesive energy and interfacial energy of ferrite (100)/NbC (100) and TiC (100)/NbC (100) interfaces have been investigated by the first-principles calculation. Moreover, the heterogeneous nuclei mechanism of NbC particle was also analyzed. The results showed that the stacking sequences have a great influence on the cohesive energy and equilibrium interfacial separation of the above-mentioned interfaces. Compared with C-terminated interfaces, the cohesive energy of Nb-terminated ones is lower while the equilibrium interface distance is larger. Among the two C-terminated interface structures, the interfacial energy between the NbC and ferrite is 4.54 J/m², which is larger than that of NbC/TiC interface (1.80 J/m²). Therefore, NbC particles prefer heterogeneous nucleation on TiC particles surface rather than the ferrite matrix, which agrees well with the experimental result.

Keywords

first-principle calculation / interface energy / cohesive energy / precipitation