Effect of Yttrium Addition on Microstructure and Hardness of Cast EV31A Magnesium Alloy

Abstract

The effect of the rare earth (RE) element Y on the microstructure and hardness of (Mg–0.5Zn–0.5Zr–2.8Nd –1.5Gd) wt% Mg alloy investigated. 1 wt. % Y was added and compared with the base alloy. The microstructure results show the refinement of the grain by the addition of Y and the grains became smaller about 31.8 % and the volume fraction was increases 11.1% %, which led to the increment of hardness from 48.33 HV (as-cast EV31A) to 53.71 HV (as-cast EV31A +1 Y). Energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) results showed that the base alloy mainly contained α-Mg matrix and Mg-(Nd, Gd) as a second phase crystallized along the grain boundaries and addition of (Y) yttrium resulted in the formation of the new phase, Mg-Zn-Y-phase was found as a new ternary phase, where Y combined with the original second phase.

The yttrium substitution impact on mechanical properties of biodegradable Mg66Zn30Ca4 alloy

“…The main goal was to improve the mechanical and corrosion properties by microalloying with yttrium (Y). The positive effect of Y on the microstructure and hardness of various systems of Mg-based alloys was observed [15,16]. In the case of Mg-Cu amorphous alloy, adding Y improved NaCl corrosion resistance [17].…”

Microstructure and Mechanical Properties of Magnesium ZRE1 (Mg-Zn-Zr) Alloy with Rare Earth Element (Samarium) Addition

“…ZRE1 is one of many Mg alloys available in the market nowadays. ZRE1 is an Mg alloy containing RE metal with the addition of zinc and zirconium, forming Mg-RE-Zn-Zr (Ahmad et al, 2017a). The detailed chemical composition of the ZRE1 alloy is shown in Table 1.…”

“…Currently, ZRE1 is used in the aerospace industry for intermediate casings on Tay engines, gearboxes of RB211 engines, and gearboxes of Tay engines (Materialstechnology, 2019). Research by (Ahmad et al, 2017a) explored the effect of Praseodymium (Pr) addition on the microstructure and hardness of cast ZRE1 Mg alloy. They reported that 1 wt.% Pr addition on ZRE1 cast alloy reduces the grain size of ZRE1 alloy by around 37%.…”

The Influence of Holmium on the Microstructure and Hardness of Mg-Nd-Gd-Zn-Zr Alloys

“…However, magnesium alloys generally show medium strength with restricted ductility at room temperature due to their hexagonal close pack structure [2]. In the recent years, magnesium alloys containing rare earth elements (RE) have received a considerately significant attention in the industry due to high mechanical strength [3] compared to the without rare earth element addition.…”

“…Solution strengthening is significantly affected by the large solubility of the heavy rare earth in magnesium at high temperature. Therefore, a lot of researches activities and developing new magnesium with heavy rare earth elements have been carried out [3,[13][14][15]. Holmium (Ho) is the one of an important element in heavy rare earth elements.…”