Differentiating the mechanical response of hierarchical magnesium nano-composites as a function of temperature

The effect of temperature change on quasi-static mechanical response of monolithic Mg alongside hierarchical Mg/Al–Al2O3 nano-composites synthesized through powder metallurgy route followed by microwave assisted rapid sintering technique and hot extrusion in 25–200 °C temperature range is investigated here. It was observed that in the case of both monolithic Mg and hierarchical Mg/Al–Al2O3 nano-composites, due to temperature increase, strength compromised while failure strain tremendously increased. The asymmetry in tension and compression also tends to vanish as temperature increases. These observed variations in strength and ductility were ascribed to the activity of non-basal slip systems and dynamic recovery at high temperature. It was also observed that presence of composite Al–Al2O3 particles (level-I particles) significantly assisted in improving mechanical response of Mg either at ambient or elevated temperature. Considering the crystallographic texture, the different mechanical response of Mg due to presence of level-I particles as a function of temperature is differentiated here.

► Presence of Al–Al2O3 particle weakens the basal and accentuates the prismatic texture.
► Mg/0.972Al–0.66Al2O3 shows the best mechanical properties in all temperatures.
► Transition from twinning to slip dominated flow occurs at T > 100 °C.
► Tension–compression asymmetry tends to vanish as temperature increase.