Abstrakt
Two magnesium alloys containing yttrium and rare-earth elements were processed by equal channel angular pressing (ECAP) to explore the effect of the small addition of zirconium on the resulting microstructures. The composition of the alloys was Mg?3.8wt%Y?2.6 wt%RE?0.45 wt%Zr (WE43) and Mg?4.1wt%Y?2.8wt%Nd (WN43), respectively.
It is shown that small Zr addition facilitates the formation of small secondary phase particles. The particles become smaller, and their distribution is denser.
Consequently, the grain nucleation processes are more active, grain growth is suppressed, and the final grain size is smaller. The faster nucleation rate affects the texture formation during ECAP as well.
It is shown that this effect is independent of the initial microstructural condition concerning both the grain size and the presence/distribution of secondary phase particles. The positive impact of Zr was proven employing scanning and transmission electron microscopy, texture measurements by X-ray diffraction and further reflected in the improved strength of the material in terms of microhardness and compression testing.
It was shown that, in this way, the microstructure and texture of MgRE alloys could be effectively tailored by small Zr additions.