Tensile and Fatigue Behavior of High Pressure Die Cast AE44 Magnesium Alloy at Elevated Temperatures

Tensile and cyclic behavior of high pressure die cast AE44 magnesium alloy have been studied at room temperature and elevated temperatures up to 350°C. Anelastic behavior has been found in both tensile and cyclic deformation at the temperature below 150°C. With increasing temperature, the anelasticity disappears, and tensile and cyclic behaviors become similar to other engineering materials, such as steels and aluminum alloys, i.e. the total strain contains only elastic strain and plastic strain. A method to determine the yield strength at 0.2% plastic strain (σ0.2) is proposed. By using the proposed method, the yield strength σ0.2 is higher than that determined using the traditional method, which is more suitable to the materials that do not exhibit anelasticity. It is believed that the anelasticity is closely related to twinning in Mg alloy, which disappears at elevated temperatures.