Application of a microstructural characterization uncertainty quantification framework to Widmanstätten α-laths in additive manufactured Ti-6Al-4V

This work applies statistical analysis and uncertainty quantification tools developed for characterizing virtual microstructures in three dimensions to a two-dimensional experimental investigation of Ti-6Al-4V Widmanstätten α-lath thicknesses obtained from back-scattered electron (BSE) or electron back-scatter diffraction (EBSD) images on two thin-walled samples manufactured via the LENS® process. The Materials Image Processing and Automated Reconstruction (MIPAR™) software optimizes unique recipes for conversion of the BSE or EBSD images to binary data, and subsequently computes the inverse of the linear intercept for each α-lath. Mean α-lath thicknesses and discrete probability density functions (PDFs) of inverse intercepts are used to make quantitative comparisons of α-lath structures at different heights throughout the thin walls. Real-time thermal data collected during the LENS® experiment is then compared to quantitative microstructural results in order to determine trends between α-lath structures, thermal gradients, and melt pool areas across experimental process parameters.