Microstructure and texture studies on twin-roll cast AZ31 (Mg–3wt.%Al–1wt.%Zn) alloy and the effect of thermomechanical processing

摘要: Abstract The microstructure and texture of the twin-roll cast (TRC) AZ31 (Mg–3 wt.%Al–1 wt.%Zn) sheet, with a thickness 6 mm, have been investigated. TRC exhibits dendritic columnar equiaxed grains. These contain Al–Mn Mg–Al–Zn second-phase particles that are approximately 1 μm in size. This heterogeneous structure is attributed to effect cooling rate, which varies from 325 °C/s on surface ∼150 °C/s mid-thickness sheet. No segregation, but certain degree macrosegregation observed persists after annealing rolling. Recrystallization at 420 °C leads bimodal grain-size distribution, while fine-grain obtained rolling annealing. sheet basal textures (i) as-received, (ii) rolled (iii) rolled-annealed conditions. However, post-annealing produces relatively random has not previously conventional randomization particle-stimulated nucleation new grains structure. preliminary evaluation mechanical properties indicates such treatment slightly increases ultimate tensile strength (UTS), significantly improves elongation.