An alternative in-grain misorientation axes analysis for slip activity: A case study in a magnesium alloy

Abstract

Electron backscatter diffraction (EBSD)-based in-grain misorientation axes (IGMA) analysis is widely employed to elucidate dislocation slip activity in deformed materials. This work introduces an alternative, long-range IGMA method using non-consecutive pairs, in contrast to the conventional short-range method using consecutive pairs. By expanding the evaluation distance between two pixels to allow for the presence of more grain-scale stochastically stored dislocations (SSDs) of opposite sign and their mutual cancellation, the long-range method enhances the detection of grain-scale geometrically necessary dislocations (GNDs) that are essential for maintaining grain continuity upon deformation but may be overlooked by the short-range IGMA method. We validate this approach on a highly textured Mg-3Al-1 Zn (AZ31) alloy compressed along two directions and identified different slip systems accounting for grain-scale lattice curvature of each case. The work underscores the complementary value of integrating spatially and angularly separated non-consecutive pairs into IGMA analyses for deformation of polycrystals.