Influence of processing route on microstructure and mechanical properties of two Mg–Ni–Y–RE alloys

The effect of the processing route on the microstructure and mechanical properties of two Mg–Ni–Y–CeMM alloys has been evaluated. The alloys processed by a powder metallurgy route presented higher strength, thanks to the finer grain size and more homogeneous dispersion of second-phase particles. In the alloys prepared by hot extrusion of as-cast rods, hardening induced by coarse second-phase particles was higher due to load transfer from the magnesium matrix towards the particles. Irrespective of the processing route, the absence of decohesion between the different interfaces in the Mg–Ni–Y–CeMM alloys evidenced their inherent strong nature.

► Processing of fine-grained Mg–Ni–Y–CeMM alloys by powder metallurgy (PM).
► Microstructural changes resulting from the use of different processing routes.
► Major contribution to the strength in PM alloys is due to the fine grain size.
► Large load transfer contribution in alloys prepared by conventional techniques.
► Inherent strong interfaces between the phases constituting Mg–Ni–Y–CeMM alloys.