Characteristics of superplasticity domain in the processing map for hot working of an Al alloy 201420vol.%Al 2O 3 metal matrix composite

Abstract

The processing map for hot working of Al alloy 201420vol.%Al 2O 3 particulate-reinforced cast-plus-extruded composite material has been generated covering the temperature range 300–500 °C and the strain rate range 0.001–10 s −1 based on the dynamic materials model. The efficiency η of power dissipation given by 2m (m + 1) , where m is the strain rate sensitivity, is plotted as a function of temperature and strain rate to obtain a processing map. A domain of superplasticity has been identified, with a peak efficiency of 62% occurring at 500 °C and 0.001 s −1. The characteristics of this domain have been studied with the help of microstructural evaluation and hot-ductility measurements. Microstructural instability is predicted at higher strain rates above (1s −1) and lower temperatures (less than 350 °C).