Effect of addition of mutually soluble and insoluble metallic elements on the microstructure, tensile and compressive properties of pure magnesium

In the present study, pure magnesium incorporated with metallic elements was synthesized using the disintegrated melt deposition technique followed by hot extrusion. The metallic elements added include: (i) mutually soluble element, aluminium (Al), (ii) insoluble element, titanium (Ti) and (iii) a combination of mutually soluble and insoluble elements (Al and Ti). The addition of the combination of elements was carried out into two ways: (a) addition after prior ball milling and (b) direct addition. The developed Mg-based materials were investigated for their microstructural and mechanical properties. Microstructural investigation revealed significant grain refinement due to metallic addition. The evaluation of mechanical properties showed significant improvement in microhardness, tensile and compressive properties of all the Mg-materials when compared to pure magnesium. The addition of individual elements resulted in the formation of Mg–3Al alloy and Mg–5.6Ti composite, and improved both the strength and ductility. When the elements were ball milled, Al3Ti intermetallic was formed due to solid state reaction resulting in Mg–(3Al + 5.6Ti)BM composite, which was absent during direct addition (Mg–3Al–5.6Ti). The Mg–(3Al + 5.6Ti)BM composite showed the highest strength, however at the expense of ductility, while the Mg–3Al–5.6Ti showed relatively lower strength properties. The observed difference in behaviour between Mg–3Al–5.6Ti and Mg–(3Al + 5.6Ti)BM is primarily attributed to the Al3Ti intermetallic phase formation and the change in morphology and distribution of the metallic elements due to the ball-milling process.