Coupling the semi-solid treatment and hot extrusion to strengthen a Mg-Zn-Gd alloy containing I-phase

Through a novel deformation process with coupling the semi-solid treatment and extrusion, a Mg-1.5Zn-0.25Gd (at.%) alloy exhibit ultimate tensile strength (UTS) of 444 Mpa, yield strength (YS) of 408 MPa and elongation of 12.5%. The microstructure and mechanical properties of the Mg-Zn-Gd alloy were investigated. The results indicated that the initial micro particle-shaped icosahedral quasicrystal phase(I-phase) was changed into lamellar-like eutectic with a thickness of 80 +/- 10 nm after semi-solid treatment and then sharply broken into nano particles during the following extrusion process. The high strength obtained is attributed to the large amounts of nano-sized I-phase particles and the accompanying bimodally-grained magnesium matrix. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A Mg-1.5Zn-0.25Gd alloy underwent microstructural changes through semi-solid treatment and extrusion, resulting in high strength due to the presence of nano-sized I-phase particles and bimodally-grained magnesium matrix.