Microstructure evolution and mechanical properties of quasicrystal-reinforced Mg–Zn–Gd alloy processed by cyclic extrusion and compression

• CEC method was firstly applied on Mg–Zn–Gd alloy and enhanced its mechanical properties greatly.
• The growing up of nanoscale I-phase during deformation was firstly observed.
• The texture weakening effect of I-phase was proved to exist and contributed to the ductility.

Mg–1.5Zn–0.25Gd (at.%) alloy reinforced by icosahedral quasicrystalline phase (I-phase) was fabricated and subjected to cyclic extrusion and compression (CEC) at 350 °C to investigate the microstructure evolution during CEC and its effect on the mechanical properties. It is observed that, during CEC, the microstructure of the alloy was greatly refined by dynamic recrystallization (DRX), large numbers of I-phase particles precipitated and then grew up, the texture of the alloy was obviously weakened. These changes in microstructure improved the mechanical properties of the alloy significantly and the alloy processed by 8 passes CEC exhibited outstanding plasticity of 31.4% and moderate yield strength of 161 MPa.