Thermal deformation behavior, microstructural evolution involving LPSO phases and strengthening mechanisms of the Mg-9Gd-2Er-0.5Zn alloy

This work systematically investigates the thermal deformation behavior, microstructural evolution involving LPSO phases, and strengthening mechanisms of the Mg-9Gd-2Er-0.5Zn alloy under conditions of 648–773 K and 0.001–1 s⁻¹. The results show that, under low Z conditions, non-basal slip shears grain boundary (GBs) blocky LPSO (B-LPSO) phases into smaller blocks, enhancing dynamic recrystallization (DRX) via particle-stimulated nucleation mechanism. Moderate Z conditions feature coexisting intragranular lamellar LPSO (L-LPSO) and GB B-LPSO phases: L-LPSO inhibits DRX and basal slip activating, while B-LPSO promotes DRX, yielding a bimodal microstructure. High Z conditions induce severe stress concentration at GB B-LPSO networks, reducing ductility. The extruded Mg-9Gd-2Er-0.5Zn alloy achieves a UTS of 397 MPa, YS of 360 MPa, and El of 12.5 %, with strengthening mechanisms further analyzed.

Duke Scholars

Author Zhaohui Wang Pathology