SIMPLIFIED STATISTICAL-MODEL FOR COMPETITIVE SEGREGATION KINETICS - APPLICATION TO THE FE-6AT-PERCENT-SI ALLOY SURFACE

From the statistical model of S. Hofmann and J. Erlewein which describes the segregation kinetics in binary solutions, the authors have developed a simplified statistical model for ternary solutions, taking into account the interactions between atoms. They have introduced an approximation which reduces to three the number of equations required for each segregating species; this allows a gain in computer time. This model was used to interpret the competitive segregation kinetics between phosphorus and silicon recorded by Auger spectrometry at the surface of a polycrystalline Fe-6at.%Si alloy at 923 K. Good agreement was achieved between experimental and calculated curves with a vaporization energy of phosphorus of 311.41 kJ mol-1 and a surface P-Si repulsive energy of 23 kJ mol-1.