Effects of the extrusion on the mechanical properties of Mg-Zn-Y alloy reinforced by quasicrystalline particles

Abstract

Mg alloys stand on the center of investigation due to their high potential of application to the structural area as well as the functional materials field, corresponding to the low density and abundance. Mg alloys are playing an important role in the automotive, aircraft and electronic industries because of their high specific strength. However, crystalline Mg based alloys usually exhibit poor corrosion resistance and are mechanicalIy brittle as a result of the hexagonal close-packed (HCP) crystal structure of magnesium. The problem has been modified by an addition of rare earth elements and reported a remarkable improvement in the properties. In 1993, astable icosahedral quasicrystal phase in Mg- Zn-Y temary alloys was frrst found by Luo . icosahedral quasicrystal phases (I-phase), with their unusual quasi-periodic lattice structure, have unique properties, such as high hardness, high corrosion resistance, low coefficient offriction, low surface energy, etc. In this work, Mg-Zn-Y alloy powders were prepared by industrial gas atomization technique. The microstructure and mechanical properties of Mg-Zn-Y alloy powders reinforced with icosahedral quasicrystalline particles (I-phase) were investigated after extrusion at 673 K. The effects of extrusion ratio and elemental composition on the microstructure and mechanical properties of the alloy were analyzed a?1d the strengthening effect of 1 -phase was discussed. The results show that the I-phase is significantly refmed on extrusion. At room temperature, the alloy extruded ratio at 20: I exhibits better tensile mechanical properties as compared to the alloy extruded ratio at 10: 1. The Yield strength of20:1 at room temperature is 390 MPa, UTS 480MPa and elongation about 14%‘At 10:1, a UTS of 400 MPa is obtained.