Effect of temperature and strain rate on compressive response of extruded magnesium nano-composite

The hot deformation behaviour of extruded magnesium-zinc oxide nano composite has been studied using hot compression test. The test was conducted in the temperature range of 250-400 °C and in the strain rate range of 0.01 to 1.5 s−1.The processing map was obtained using the power dissipation efficiency with the functions of temperature and strain rate. The workability and instability domains were observed in the processing map for a nano composite. The optical microscopy (OM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images were used to confirm the formation of dynamic recrystallization (DRX), dynamic recovery (DRY) and instability regions. The workability region of the composite was identified at a working temperature of 400 °C and the strain rate of 0.01 s−1 from the processing map. The instability regions were observed at higher strain rates (>0.1 s−1) and temperatures (250-400 °C).