Microstructure and mechanical properties of a Mg-Zn4.3Y0.7 alloy powder reinforced by quasi-crystalline particles

Abstract

Rapidly solidified (RS) Mg-Zn4.3Y0.7 alloy powders were prepared by using a gas atomization device, followed by the warm extrusion. The microstructure and mechanical properties were analyzed by Scanning Electron Microscopy (SEM) and Energy Dispersive Spectroscopy (EDS), and the constituent phases were characterized using X-ray diffraction (XRD). The microstructure of the powders indicated that the icosahedral Mg3YZn6 (I-Phase) quasi-crystals were distributed in the alpha-Mg matrix. I-phases on the order of 0.5 mu m were generally formed along the grain boundaries. The powders were extruded with an area reduction ratio to identify the extrusion behavior. As the extrusion ratio increased from 10:1 to 15:1 and 20:1, the microstructures had a more uniform distribution of the I-phase and showed increased mechanical properties, such as tensile strength and elongation.