Effect of different solute diffusivities on precipitate coarsening in ternary alloys

According to Gibbs phase rule, ternary two phase alloys have a single degree of freedom at equilibrium at a given temperature. Thus, multiple precipitate-matrix equilibrium compositions are possible at the interface. From Philippe-Voorhees' (PV) theory (Philippe and Voorhees, 2013), it is known that during coarsening in multicomponent alloys, precipitate-matrix compositions at the interface during coarsening are not just dependent on the Gibbs-Thomson effect but also on the relative mobilities of the solute elements. Our computer simulations, based on a phase field model, show that this effect of different solute diffusivities on size-dependent particle composition is more pronounced in alloys richer in the slower diffusing solute. (C) 2018 Elsevier B.V. All rights reserved.