Abstract
A technique is introduced to extend traditional polarized-light microscopy to obtain quantitative c-axis orientation images of reflective non-cubic crystal grains such as α-titanium. The technique is based on multiple generalized illumination and detection states in a laser polarimeter and a physical model mapping resulting image irradiance to crystal orientation, and is demonstrated by comparing relative-orientation images with EBSD orientation maps of a Ti-6Al-4V sample. The new technique is shown to be somewhat more tolerant than EBSD to mechanically-induced surface roughness and deformation, although grain contrast for a Ti-7Al sample was found to be only weakly correlated with roughness as measured by an AFM.