Improvement of microstructure and mechanical properties of Mg–8Gd–3Y by adding Mg3Zn6Y icosahedral phase alloy

Mg–Zn–Y quasicrystal alloy (QA) particles reinforced composite was prepared using an adscititious method, and characterized using scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and tensile testing technique at room temperature. Experimental results indicate that α-Mg columnar dendrite gradually becomes fine equiaxed dendrite and ellipsoidal cellular dendrite as more Mg–Zn–Y QA particles are added into the matrix alloy. Thread-like Mg24(Gd,Y)5 phases and rod-like Mg5(Gd,Y) phases are replaced by lamellar Mg24(Zn,Gd,Y)5 compounds and granule Mg3Zn6(Y,Gd) quasicrystal I-phases. The ultimate tensile strength and yield strength of the composite increase by about 45 MPa and 20 MPa respectively when the amount of QA particles added increases from 3% to 15%. It can therefore be concluded that the microstructure and mechanical properties of Mg–8Gd–3Y alloy can be improved by adding QA particles.