Effect of individual and combined addition of micro/nano-sized metallic elements on the microstructure and mechanical properties of pure Mg

In this study, the effects of the addition of individual micro- and nano-sized metallic elements (micron-Ti and nano-Cu) and their combination on the microstructure and mechanical properties of pure Mg were investigated. The materials were produced by rapid microwave sintering assisted powder metallurgy technique followed by hot extrusion. From the microstructural characterization and mechanical property evaluation, it was identified that the solid solubility, size and the method of addition of elements significantly influenced the properties. While the insoluble micron-Ti enhanced the strength and reduced the ductility due to weak interface, the addition of nano-Cu with relative solid solubility enhanced the strength due to the formation of Mg2Cu intermetallics and retained the ductility. The positive effect of their combined addition was found to be more pronounced when they were pre-processed, rather than their direct addition. The change in particle morphology, Ti3Cu intermetallic formation and good interfacial bonding with the matrix achieved due to pre-processing contributed towards its superior strength and ductility.

► Pure Mg incorporated with metallic elements has been successfully synthesized. ► Addition of metallic elements to pure Mg improves the strength properties at the expense of ductility. ► Combined addition of micro-Ti and nano-Cu to pure Mg with and without ball milling was carried out. ► Prior ball milling of micro-Ti and nano-Cu result in the formation of Ti3Cu intermetallic phase and elimination. ► Mg–(5.6Ti + 3Cu)BM, showed better strength and ductility compared to Mg–5.6Ti–3Cu.