A technique-synergy for the mesoscale, three-dimensional modeling and simulation of metal alloys
Kiran Narayanan (KAUST), Tamer El Sayed (KAUST)
Computational Materials Design via Multi-scale Modeling
Wed 10:45 - 12:15
Barus-Holley 190
An approach that employs a synergy of microstructural characterization, quantification and simulation techniques is used to develop a high fidelity, three-dimensional model of the microstructure of Aluminum Alloy 6061 (AA 6061). First, the secondary intermetallic phase particles present in the alloy are identified using high-resolution TEM imaging as well as an investigation of the elemental distributions using Energy-Dispersive X-ray Spectroscopy (EDXS). Second, Electron Backscatter Diffraction (EBSD) and EDXS, are used in conjunction with Focused Ion Beam (FIB) tomography, in order to characterize a 50umx50umx35um volume of the material. The EBSD data is reconstructed using a novel procedure that uses the information from the segmentation of secondary phase particles to re-index the data at voxels belonging to phases other than the aluminum matrix, and then performs region-growing based on mis-orientation of grains. After reconstruction, a microstructural quantification module is used to quantify the distribution of secondary phase particles, and, texture and morphology of the primary phase. Finally, the reconstructed microstructure is discretized and simulations are performed using the Crystal Plasticity - Finite Element Method (CPFEM) to study to uniaxial compression of the alloy. In contrast to conventional microstructural modeling techniques that rely on image-based, qualitative information along with a morphological measure such as grain size, the approach developed in this study provides a tool that enables high fidelity, 3-D modeling of real microstructures of metal alloys. It is a step towards realizing accurate predictions from meso-scale models and contributes towards the overarching goal of simulation-based design of materials [1]. Reference [1] D.L. McDowell, D. Backman, Simulated-Assisted Design and Accelerated Insertion of Materials, in Computational Methods for Microstructure-Property Relationships, Springer (2011) 617-647.