A discrete lattice plane analysis of coherent f.c.c./B1 interfacial energy

Abstract

A discrete lattice plane, nearest neighbor, broken bond model with constant bond energies, which had been used to calculate the energy of coherent interphase boundaries in substitutional alloys, was extended to a ternary substitutional–interstitial system to study the chemical interfacial energy between a f.c.c. solid solution and a B1(NaCl) compound. When the regular solution interaction coefficient of substitutional (metal) atoms is positive, interstitial (non-metallic) atoms which have different bond energies with the two metal atoms tend to increase both the composition difference and the interfacial energy. Even when the interaction coefficient of metal atoms is negative, a miscibility gap and a gradual composition change across the interface occur. The anisotropy of the interfacial energy varies widely according to the magnitude of interaction between the metal and the non-metallic atoms.