Sibo Xu

Deformation behaviour of hot extruded Mg alloy AZ31 during compressive deformation

Abstract Deformation behaviour of a hot extruded Mg–3Al–1Zn alloy subjected to uniaxial compression at room temperature was investigated. Microstructure evolution showed that the amount of lenticular shaped extension twins increased with the increase in true strain when it was lower than ∼4% but decreased when it was higher than ∼4%. Previous studies indicated that detwinning occurred. However, we have demonstrated in the present paper that no detwinning occurred, but a process of twin growth and coalescence, leading to an analogous detwinning phenomenon observed in the optical micrographs because most of the matrixes were consumed. A strong texture evolution occurred in this process, and the reorientation produced by strong twinning was mainly responsible for strain hardening when compressed along the extrusion direction.

Continuation of twins across grain boundary in extruded Mg–3Al–1Zn alloy

Abstract Paired twins in an extruded Mg–3Al–1Zn alloy are investigated by using electron backscattered diffraction in the current paper. The results show that these paired twins are discovered at low misorientation grain boundaries. The twin variant (1–102)[−1101] is operated in the paired twins. Additionally, a macroscopic angle exists in the paired twins and is determined by the c axis misorientation of the grains.

Modified twinning behaviour induced by texture evolution in hot rolled Mg–3Al–1Zn alloy

Abstract Compressive deformation along the rolling direction (RD) of a hot rolled Mg–3Al–1Zn alloy is applied to investigate the texture evolution and the recompressive yield strength (RYST) along the transverse direction (TD). Preferential orientation of the basal and prismatic planes is generated by the plastic deformation. Precompression along RD results in one plane of {10–10} aligned nearly perpendicular to the normal direction to the rolling plane. As the compressive strain along RD increases, the RYST shows an earlier raised and later decreased trend. The modified twinning mechanism is investigated using X-ray diffraction and electron backscattered diffraction observations. The results reveal that {10–12} twinning in the matrix dominates the recompression along TD, while the formation of {10–12}–{10–12} twins becomes comparatively easier to occur in the previous {10–12} twins for large precompressed samples.