The Effect of Strain Rate and Temperature on the Deformation of Die Cast AM60B 950425

A number of emerging automotive applications of die cast Mg-Al alloys involve components such as seats, steering wheels and instrument panel supports. These components may be subjected to strain rates as high as 200 s^-1 during an automobile collision. Deformation and fracture behavior during high rates of loading are, therefore, of considerable interest. However, little work has been done to measure the effect of elevated strain rates or temperature on the energy absorption properties of the Mg-Al alloys. Thus, in an effort to provide additional information, the present work reports that the mean yield strength and strain hardening rates for die cast AM60B appear to be a strong function of strain rate from 10^-3 s^-1 to 10³ s^-1 and temperature from -196 to 25 °C. Both the total energy absorption and total deflection of AM60B Charpy impact bars increased with increasing temperature in the range from -196 to 300 °C. Furthermore, the normalized total energy absorption / total deflection averaged 1.2 kJ/mm over the entire temperature range. However, the energy absorption for a specific deflection decreases over this same temperature range.