Hot deformation behaviour of as-cast Mg–2Zn–1Mn alloy in compression: a study with processing map

The deformation behaviour of as-cast Mg–2Zn–1Mn alloy in the temperature range 300–500 °C and in the strain rate range 0.001–100 s−1 has been studied using processing maps. For obtaining the processing map, the variation of the efficiency 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. The map exhibited a domain of dynamic recrystallization (DRX) occurring at 450 °C and 0.1 s−1 which are the optimum parameters for hot working of the alloy. The material exhibits grain boundary cracking domain with a higher efficiency at temperatures higher than 450 °C and at lower strain rates. At strain rates higher than 3 s−1, the material undergoes flow localization which has to be avoided in mechanical processing for obtaining consistent properties.