Abstract
Mg-based alloys with rare-earth alloying elements are promising hardenable lightweight materials with good mechanical properties even at elevated temperatures. Ductility and strength of these alloys can be improved by grain refinement.
Ultra fine grained Mg alloys with gram size around 100 nm were successfully prepared by high-pressure torsion. Ultra-fine-grained structure can enhance diffusivity of alloying elements due to the significant volume fraction of grain boundaries.
As a consequence, precipitation effects in ultra-fine-grained alloys may occur faster than in corresponding coarse-grained materials. This phenomenon was examined in this work by comparison of the precipitation sequence in Mg-Tb-Nd and Mg-Gd alloys with ultra-fine-grained structure and corresponding coarse-grained alloys.