Determining material parameters using phase-field simulations and experiments

• DOI: 10.1016/j.actamat.2017.02.056
• Publication Date: 2017-02-22T19:32:31Z
• Authors: Jin Zhang; Stefan O. Poulsen; John W. Gibbs; Peter W. Voorhees; Henning F. Poulsen
• Keywords: Phase-field method; Al alloys; Temporal evolution; Polymers and Plastics; Coarsening; 0103 physical sciences; Metals and Alloys; Ceramics and Composites; X-ray tomography; 01 natural sciences; Electronic, Optical and Magnetic Materials

Abstract A method to determine material parameters by comparing the evolution of experimentally determined 3D microstructures to simulated 3D microstructures is proposed. The temporal evolution of a dendritic solid-liquid mixture is acquired in situ using x-ray tomography. Using a time step from these data as an initial condition in a phase-field simulation, the computed structure is compared to that measured experimentally at a later time. An optimization technique is used to find the material parameters that yield the best match of the simulated microstructure to the measured microstructure in a global manner. The proposed method is used to determine the liquid diffusion coefficient in an isothermal Al-Cu alloy. However, the method developed is broadly applicable to other experiments in which the evolution of the three-dimensional microstructure is determined in situ. We also discuss methods to describe the local variation of the best-fit parameters and the fidelity of the fitting. We find a liquid diffusion coefficient that is different from that measured using directional solidification.