Kinetics of hot deformation in Mg/Nano-Al2O3 composite

The hot deformation behavior of extruded Mg/nano-Al₂O ₃ composite has been studied in the temperature and strain rate ranges of 300-500°C and 0.0003-10 s^-1. In the lower strain rate regime (-1), the apparent activation energy evaluated is much higher than that for lattice self-diffusion. At higher strain rates, the behavior of the composite is similar to that of the matrix material and is controlled by grain boundary self diffusion. The prior particle boundaries in the composite, which are decorated by the nano-alumina particles, are stable and only kink under compression parallel to the extrusion direction.