Characterization and 3D Modeling of Microstructure and Texture in Two-phase Titanium Alloys

This work explores the processing-microstructure-property relationships in two-phase titanium alloys such as Ti-6Al-4V that are used for aerospace applications. The motivation is reduction of the buy-to-fly ratio of titanium alloys. Microstructures produced by the conventional Vacuum Arc Remelting (VAR) method are compared with the relatively new Electron Cold Beam Hearth (EBCH) melting. Microstructure and texture of the two sources of materials are characterized using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and Electron Backscatter Diffraction (EBSD). To model their properties, three-dimensional synthetic digital microstructures are generated based on the experimental characterization data. An open source software package, DREAM.3D, is used to create heterogeneous two-phase microstructures that are representative of titanium alloys. Crystal plasticity models based on the fast Fourier transform algorithm (FFT) are used to simulate the deformation response of the material at both microscopic level and continuum level. A data driven approach is followed to understand and model the processing-microstructure-property relationships in Ti-6Al-4V alloy.