Slip transfer, slip blocking and slip-to-twin transfer at grain boundaries in a WE43 Mg alloy

• Slip transfer/blocking in WE Mg alloy was analyzed by means of 2D (EBSD, ST-MLRA) and 3D (DCT) experimental techniques. • Slip transfer events were tightly gathered in the high-compatibility region where both the Luster-Morris parameter ( m ) and the LRB factor exceeded 0.9. • Slip blocking was dominant (80.4 %) and slip to twin transfer occurred at high misorientation angles (>20°). • The integration of 3D grain morphology with actual slip system identification provides a comprehensive framework for evaluating intergranular deformation in Mg alloys. Slip transfer/blocking at grain boundaries was studied in a WE43 Mg alloy through a combined experimental approach involving electron backscatter diffraction (EBSD), slip trace modified lattice rotation analysis (ST-MLRA), and diffraction contrast tomography (DCT). Slip (basal slip) transfer occurred exclusively across low-angle grain boundaries (<20°), while slip blocking was dominant (80.4 %), and slip to twin transfer typically occurred at higher misorientation angles. Among the geometric descriptors analyzed, low values of κ (angle between slip directions), ψ (angle between slip plane normals), and θ (angle between the traces of the incoming and outgoing slip planes with the GB plane) were consistently associated with the slip transfer cases. Notably, slip transfer events were tightly gathered in the high-compatibility region where both the Luster-Morris parameter ( m′ ) and the LRB factor exceeded 0.9, suggesting that both serve as robust criteria for basal slip transmission across grain boundaries. The integration of 3D grain morphology with actual slip system identification provides a comprehensive framework for evaluating intergranular deformation in Mg alloys.