Identification of NdH2 particles in solution-treated Mg–2.5%Nd (wt.%) alloy

In present work, the NdH2 precipitates in Mg–2.5%Nd (wt.%) alloy were identified by various microstructural analyzing techniques including OM, XRD, TEM with EELS, SEM with EDS, etc. It was revealed that the as-cast alloy contained α-Mg solid solution and eutectic phase Mg12Nd, while there were NdH2 particles at or near the grain boundaries in 540 °C/6 h solution-treated state. As widely acknowledged, they worsen its mechanical property, especially, the cracking and fracture behaviors. Synchronously, the formation of hydride NdH2 is proved to be favored and practicable based on thermodynamics theory.