Chemo-mechanical phase-field simulations of eutectoid transformationFriday (25.09.2020) 12:50 - 13:05 M: Modelling and Simulation 1 Part of:
The phase-field method is a powerful numerical simulation technique which is capable of providing comprehensive understanding of microstructural evolution. An essential feature of these evolutions is microscopic solid-state phase transformations which are strongly driven by several different driving forces. In order to capture the interplay of chemo-mechanical configurational forces in the interfacial regions adequately, this work employs a thermodynamically consistent multiphase-field approach for diffusion driven phase transformation processes coupled with a mechanical model which satisfies the mechanical jump conditions on singular interfaces [Schneider2018, Tschukin2019]. From a chemical point of view, the model is able to account quantitatively for the diffusion-driven effects by incorporating CALPHAD based parameters [Choudhury2012].
In this work specifically, the pearlitic transformation in ferrous materials is intensively investigated. Zener's modeling of pearlite transformation in steels can be seen as the pioneering work of many microstructure evolution modeling approaches [Zener1946]. Although being well established, the model yields deviations from experimentally observed growth kinetics which cannot be ignored. Since the eutectoid transformation inarguably deals with substantial lattice mismatches between the phases, it can only be entirely understood by regarding the interplay of strain- and diffusion-driven transformation processes [Steinbach2012]. Hence, the incorporation of an extended chemo-mechanical potential enables an accurate formalism to capture coupled transformation phenomena. An in-depth analysis of the emerging stress-driven diffusion mechanisms and growth kinetics of pearlitic colonies is performed in this work to further close the gap between experimental and numerical findings in eutectoid transformation.