Mechanical and creep properties of Mg-4Y-3RE and Mg-3Nd-1Gd magnesium alloy

A study has been undertaken to reveal the microstructure, mechanical and creep properties of two Mg-4Y-3RE and Mg-3Nd-1Gd magnesium alloys. The relationship between the ageing parameters, microstructure, mechanical and creep properties was specified. Structure investigations showed that the mechanical properties maximum during the ageing at 200°C/16h (Mg-3Nd-1Gd alloy) and at 250°C/16h (Mg-4Y-3RE alloy) resulted from the formation of fine β" and β′ precipitates in the α-Mg solid solution. Further ageing led to decrease of the mechanical properties due to formation of β₁ and β phases in Mg-4Y-3RE alloy or only β phase in Mg-3Nd-1Gd. The creep tests of the Mg-3Nd-1Gd alloy at temperature 200°C in the stress range 90-150MPa show the larger creep strain and steady-state creep rate than the Mg-4Y-3RE alloy.