DEFORMATION AND FAILURE MODES OF RAPIDLY SOLIDIFIED, ULTRA-FINE GRAIN, AMX602 AND ZAXE1711 MAGNESIUM ALLOYS

摘要

This paper characterizes microstructure, mechanical properties, and the plastic flow and fracture behaviors of the high strength and high ductility, ultra-fine grain (UFG), magnesium alloys AMX602 (Mg-5.4Al-0.39Mn-1.77Ca) and ZAXE1711 (Mg-7.28Al-1.20La-1.18Ca-0.93Zn). Rapidly solidified processed (RSP) powders produced by Spinning Water Atomization (SWAP) were formed into compacts that were subsequently extruded into flat bars. Specific characteristics of the mechanical properties, and deformation and failure modes and features are revealed in response to loading conditions in tension, compression, shear, and impact. The material behaviors are shown with numerical and stress-strain test data, and power law hardening constitutive plastic flow parameters. Fracture modes and features are shown with optical and SEM microscopy. The ZAXE1711 alloy reveals lower yield strength, a high rate of strain hardening, greater ultimate strength and impact toughness, and more homogeneous less localized plastic flow and fracture.