Development of high performance Mg–TiO₂ nanocomposites targeting for biomedical/structural applications

Highlights: • Mg–TiO₂ composites are synthesized for the first time using solidification route. • Overall tensile response of Mg can be improved if vol.% of TiO₂ is at least 2%. • 0.2% CYS and compressive fracture strain of Mg are improved by nano TiO₂ addition. • Presence of TiO₂ in pure Mg reduces tensile compression asymmetry. - Abstract: Near dense low volume fraction Mg–TiO₂ nanocomposites are synthesized using disintegrated melt deposition technique followed by hot extrusion. The microstructural characterization of the nanocomposites reveal significant reduction in grain size of pure magnesium with addition of titanium dioxide with a maximum of ∼47% reduction with 2.5 vol.% TiO₂ nano addition. The X-ray diffraction studies indicate weakening of dominating basal texture of pure magnesium with addition (0.58, 0.97 and 1.98) vol.% TiO₂ nanoparticulates. The room temperature tensile properties of the synthesized nanocomposites reveal that a minimum of ∼2 vol.% TiO₂ nanoparticulates are required for strength improvement in the tensile properties of pure magnesium. With addition of 2.5 vol.% TiO₂, proof stress, ultimate tensile strength and fracture strain of pure magnesium increased by ∼37%, ∼9% and ∼31% respectively. The tensile fracture strain of the synthesized nanocomposites was found to surpass that of pure magnesium and a maximum fracture strain of ∼12% with the addition of 1.98 vol.% TiO₂ was obtained. With addition of TiO₂ nanoparticulates, the room temperature compression properties of the synthesized nanocomposites reveal an increase in the 0.2% compressive yield strength and fracture strain of pure magnesium with decrease in the ultimate compressive strength. With addition of 2.5 vol.% TiO₂, the 0.2% compressive yield strength and the fracture strain of pure magnesium increased by ∼83% and ∼33% respectively with ∼7.5% decrease in ultimate compressive strength. With the addition of TiO₂ nanoparticulates, the level of anisotropy/asymmetry of pure magnesium measured using tensile compression asymmetry values was found to be lower than that of the synthesized pure magnesium and a minimum of ∼1 for Mg 0.58 vol.% TiO₂ nanocomposite was observed