투과전자현미경을 이용한 분말압출 Mg-Zn-Y 합금의 미세조직 연구

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. However, the intrinsic low strength and corrosion resistance have limited the industrial appllication of Mg alloys. The problem has been modified by an addition of rare earth elements and reported a remarkable improvement in the properties. The typical composition bearing the high strength is Mg-Zn-Y, leading to high strength and hardness, low friction coefficient and low interfacial energy in both the ambient and elevated temperature. The improvement is corresponding to the homogeneous distribution of metastable icosahedral phase (I-phase) in the Mg phases. In this work, Mg95-Zn4.3Y0.7 powders were obtained using industrial gas atomization technique. The microstructures and phases of atomized Mg?Zn?Y alloy powders were investigated by means of scanning electron microscopy (SEM), energy-dispersive spectrum (EDS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Icosahedral phase occurred as particles about half micron size at grain boundaries and as nano-sized precipitates in the matrix.