2008 Volume 48 Issue 9 Pages 1280-1284
An ab initio study was carried out on interfacial energies and misfit strain energies at coherent interfaces between Fe(bcc structure) and MCs(NaCl structure, M=Ti, Zr, Hf). The interfacial energies at relaxed interfaces, Fe/TiC, Fe/ZrC and Fe/HfC, were 0.263, 0.153 and 0.271 J/m2, respectively. The influence of bond energy was estimated using the discrete lattice plane/nearest neighbor broken bond model. It was found that the dependence of interfacial energy on the type of carbide was closely related to changes of the bond energies between Fe, M and C atoms before and after formation of the interfaces Fe/MC. The misfit strain energies in Fe/TiC, Fe/ZrC and Fe/HfC systems were 0.390, 1.692 and 1.408 eV per 16 atoms (Fe; 8 atoms and MC; 8 atoms). The misfit strain energy became larger when the difference in lattice parameters between the bulk Fe and the bulk MCs increased.
