Microstructure, mechanical properties and fracture behavior of peak-aged Mg34Y32Nd31Gd alloys under different aging conditions

The morphology of precipitates and grain boundaries of peak-aged Mg34Y32Nd31Gd alloys under different aging conditions were analyzed by transmission electron microscopy (TEM), and the mechanical properties and fracture behavior of the studied alloys both at room and elevated temperatures were investigated. The β′′ and β′ phases are the main precipitates of the alloys peak-aged at 200 °C and 225 °C, while the alloy peak-aged at 250 °C mainly consists of β1 and β phases. Discussion on relationship between precipitates and mechanical properties, fracture behavior reveals that the precipitatesʹ density, kind and arrangement are the dominating factors influencing the mechanical properties, and the combined influence of grain boundary structure and precipitation hardening determine the fracture mechanism of Mg34Y32Nd31Gd alloys.