High fracture toughness of extruded Mg–Zn–Y alloy by the synergistic effect of grain refinement and dispersion of quasicrystalline phase

The fracture toughness of an extruded Mg–2.6 at.% Zn–0.4 at.% Y alloy with a grain size of 1 μm and containing quasicrystalline icosahedral phase was determined to be 32.5 MPa m1/2, which is much higher than conventional wrought magnesium alloys. Microstructural observations showed that the quasicrystalline phase pinned many dislocation movements and prevented void nucleation because of its coherent interface with the matrix.