Effect of Holmium and Ytterbium on Age Hardening of High-Strength Magnesium Alloy IMV7-1 of the Mg – Y – Gd – Zr System

Abstract

The kinetics of decomposition of supersaturated magnesium solid solution and of the accompanying hardening of the latter at 200°C in cast alloy IMV7-1 of the Mg – Y – Gd – Zr system alloyed with two rare-earth metals, i.e., holmium and ytterbium, is studied. Holmium and ytterbium are introduced into IMV7-1 by substituting two other rare-earth metals, i.e., yttrium and gadolinium. It is shown that the presence of holmium and ytterbium instead of yttrium and gadolinium does not change the decomposition behavior of the supersaturated solid solution but decelerates this process and lowers the effect of age hardening.