Properties of a light structural magnesium IMV7-1 type alloy of the Mg – Y – Gd – Zr system with the additions of cerium-group rare-earth metals such as samarium, neodymium, and lanthanum

Abstract

The effect of small additions of cerium-group rare-earth metals such as samarium (Sm), neodymium (Nd) and lanthanum (La) on the properties of a light high-strength structural magnesium IMV7-1 type alloy of the Mg – Y – Gd – Zr system, where yttrium (Y) and gadolinium (Gd) are yttrium-group rare earth metals, has been studied. It is established that the presence of small quantities of samarium in the IMV7-1 alloy contributes to an increase in its strength properties upon heat treatment (aging) and makes it possible to reduce the time to reach the maximum strengthening. In the case where two other cerium-group rare earth metals, neodymium and lanthanum, are present in the IMV7-1 type alloy, the strengthening upon heat treatment (aging) is also observed, but to a much lesser extent. It has also been established that, as the contents of the main alloying elements (yttrium and gadolinium) are simultaneously increased and samarium is added, the maximum strengthening of the alloys under study gradually increases, and the time to its achievement decreases. The fact that the alloying with samarium results in substantially higher strengthening of the IMV7-1 type alloy than that provided by neodymium and lanthanum is explained by a much higher solubility of samarium compared to these of neodymium and lanthanum in solid magnesium.