This study investigated the effects of equal-channel angular pressing (ECAP) on the microstructure and mechanical behaviour of pure magnesium across different pass numbers (1, 4, 8) and deformation temperatures (225, 325, 425°C). After one pass at 325°C, initial coarse columnar grains (∼1 × 3 mm) were refined to equiaxed grains averaging ∼25 µm, with minimal further refinement at higher passes, indicating microstructural stabilisation. Misorientation analysis revealed a stable grain-boundary character, with average angles of approximately 40°. Texture analysis showed {0001} basal plane tilting from 20° to 40° relative to the extrusion direction with increasing passes, attributed to sample rotation during ECAP. Yield strength increased from 12 MPa (as-cast) to 60 MPa after one pass but decreased to 41 MPa after eight passes due to dynamic recovery and texture softening, while elongation-to-failure rose from 8% to 16.7%. Deformation temperature critically influenced outcomes: at 225°C, one pass yielded finer grains (15–25 µm) compared to ∼85 µm at 425°C, resulting in superior properties (75 MPa yield strength, 15% elongation). These results demonstrate that ECAP effectively tailors microstructure and texture, enabling synergistic improvement in strength and ductility, particularly at lower processing temperatures.
