Quantification of variation range of enrichment ratio to interface segregation

Abstract A kinetic model is illustrated to reveal the intrinsic variation of enrichment ratio. The variation range is quantified by considering the interface layer and the sub-interface layer as well as the interface and the bulk as closed systems and by extending the thermodynamic theory of grain-boundary segregation. Enrichment ratio is proved to lie between the beginning and the equilibrium enrichment ratios. Surface segregation of Mg in Al-Mg alloy and grain-boundary segregation of P in interstitial-free steel are in excellent agreement to the quantified variation range, confirming the quantification is reliable. Future directions are suggested as well.