Elevated temperature deformation of die cast Mg alloy AZ91D

The elevated temperature deformation behaviour of die cast magnesium alloy AZ91D has been investigated using slow strain rate and constant load creep testing. It was found that thin section (1 mm) die cast specimens were more resistant to elevated temperature deformation than thick (6 mm) specimens. Heat treatment prior to testing also improved the creep properties. These effects are explained in terms of microstructural differences between samples with different thickness and in terms of changes that occur in the material at elevated temperatures.