Dynamic Thermomechanical Behavior of Fine-Grained Mg Alloy AMX602

Abstract This paper details the dynamic mechanical behavior of a fine-grained Mg alloy, AMX602 (Mg-6%Al-0.5%Mn-2%Ca), produced via the Spinning Water Atomization Process (SWAP), followed by compaction and extrusion, to obtain a fully dense plate. The rapid cooling from melt of SWAP results in a coarse powder with a fine-grained microstructure, and the consolidation of this powder followed by extrusion produces a relatively weak rolling texture. The mechanical behavior of the plate was measured in dynamic compression at different temperatures, quasi-static and dynamic tension at room temperature, and under dynamic shear at room temperature. In each case the behavior was probed in the different loading directions corresponding to the processing directions–extrusion, transverse, and normal. AMX602 has relatively high strength and modest ductility. Increasing the temperature increases the compressive strain-to-failure only a small amount, while reducing the flow stresses. In tension, however, the ductility in the normal direction is essentially zero, but modest in the other two directions. The large anisotropy and tension/compression asymmetry of typical rolled Mg alloys is significantly reduced in this material, and the anisotropy reduces further as the temperature increases. The dynamic shear response was measured for different shear planes but there was large specimen-to-specimen variation, however the resistance to shear localization is relatively poor. Despite the high strength of AMX602, the limited ductility hinders its performance in ballistic scenarios and restricts usage.