A finite difference method was used to investigate the effect of misfit strains, and kinetic barriers to the establishment of local thermodynamic interfacial equilibrium, upon the behavior of a coherent interface in a binary diffusion couple. Impediments to the transformation of one phase into another, and to attaining interface chemical equilibrium, were considered by using a matrix of interfacial kinetic coefficients which coupled thermodynamic driving forces to interfacial velocity and fluxes. It was found that interfacial kinetic barriers resulted in a decrease in the interfacial velocity, a change in power-law time-dependence, and large shifts in the time-dependent interfacial compositions (sometimes by up to 20at% from the time-independent equilibrium values). The interfacial compositions could shift into 2-phase or single-phase fields; depending upon various parameters, such as the initial compositions of the phases which made up the diffusion couple.

Effect of Interfacial Kinetic Barriers on Interface Motion in Binary Diffusion Couples W.C.Johnson: Metallurgical and Materials Transactions A, 1998, 29[8], 2021-6