Effect of grain refinement on the strength and corrosion of AZ31 magnesium alloy following severe plastic deformation

The quest for ever higher performance in structural applications has resulted in the outgoing development of new or improved materials with novel crystallographic textures, microstructures, and compositions. However, commercial applicability of such materials depends heavily on the development of economical and robust manufacturing methods. Due the promise of excellent properties such as superplasticity, high strength, good ductility, enhanced high cycle fatigue life, and good corrosion resistance, interest has grown in nanostructure bulk materials. Those materials are defined most often as materials exhibiting nano-crystalline grain structures and particle sizes below 100 nm in at least one dimension. In recent years, bulk nanostructure materials processed by methods of severe plastic deformation (SPD) such as Equal Channel Angular Extrusion (ECAE), have attracted the growing interest of specialists in materials science. The main object of this research is to compare the mechanical properties and corrosion behavior of Magnesium alloy, AZ31, after Extrusion and Severe Plastic Deformation by ECAE process. The ECAE process can produce intense and uniform deformation by simple shear and provides a convenient procedure for introducing an ultra fine grain size into a material. The samples were prepared by using hot extrusion methods. Hardness and potentiodynamic polarization tests were carried out on the extruded rods, and the microstructure was examined using optical, electron microscopy (SEM) and EDS.