Abstrakt
Successive precipitation processes in solution treated Mg3Y3Nd alloy were studied by electrical resistometry, by differential scanning calorimetry and by microhardness. The results were compared to those in the commercial WE43 alloy.
Five various phases known from the Mg-Gd- and Mg-Nd-type decomposition sequences form, dissolute or transform in the Mg3Y3Nd alloy. The main difference in the WE43 precipitation sequence is the absence of the 131 phase particles.
Electron microscopy confirmed that not the phase type of hardening particles but their morphology, size and orientation to the matrix determine the hardening effectiveness. Differential scanning calorimetry revealed exothermic effects connected to precipitation processes.
Apparent activation energies of individual precipitation processes correspond to those in the MgTbNd and in MgNd alloys.