Quantitative Phase-Field Modeling of Faceted Crystal Dissolution Processes

This article showcases a systematic and generalized phase-field modeling approach for addressing the phenomenon of faceted crystal dissolution in different crystalline solids, in two and three dimensions. A thermodynamically consistent phase-field model was adapted to account for anisotropies in the surface energy and kinetic mobility associated with the crystal surface that evolves during dissolution. Two significant and novel aspects of this work are: (I) the proposed general prescription of anisotropy parameters and (II) quantitative process simulation, within the phase-field modeling framework. The prescription allows us to simulate dissolution in different crystal–liquid systems, where the crystal may exhibit arbitrary growth and dissolution facets. Moreover, the order of precedence and relative velocities of facets can be precisely controlled. To demonstrate the procedure of quantitative modeling, we considered the system of α-quartz in silica-undersaturated solution under the physical conditions from previous experiments and determined other input model parameters from the existing literature. Further, the missing anisotropy parameters were retrieved based on simulations of dissolving single crystals. Following the proposed prescription and the procedure of parameter-set generation, dissolution processes in other crystal–liquid systems under different physical conditions can be modeled. The general applicability, capabilities, and performance of this model in capturing diverse system-specific dissolution behavior are demonstrated through representative numerical examples.