Inhomogeneous strain associated with Lüders band propagation in an FeCo-2V alloy

The inhomogeneous strains associated with Lüders bands in FeCo-2V have been studied. Mechanical testing revealed distinct elastic, Lüders band propagation, and work-hardening regimes. Digital Image Correlation (DIC) strain maps confirmed localised deformation during band propagation, transitioning to homogeneous plasticity post-saturation. Electron Backscatter Diffraction Kernel Average Misorientation (EBSD-KAM) analysis showed elevated misorientation angles in deformed regions, correlating with increased dislocation density. Synchrotron X-ray diffraction (XRD) showed peak broadening during Lüders band propagation, attributed to dislocation-induced lattice distortions that were quantified through Williamson-Hall analysis. The results demonstrate that Lüders bands in FeCo-2V arise from dislocation accumulation, with uniform peak width regions in XRD maps correlated with band propagation, while post-plateau work-hardening increased average peak widths. These findings provide insights into strain localisation in FeCo-2V.