Research status of rheo squeeze casting of magnesium alloy

Rheo squeeze casting technology is a kind of squeeze casting technology, in which the semi-solid slurry is poured into the mold cavity. Because of the combination of the advantages of semi-solid forming technology and squeeze casting technology, this process has attracted people’s attention in recent years, and has been used to produce aluminum alloy auto parts. The existing research and application focus on aluminum alloy, while the rheo squeeze casting technology of magnesium alloy is in the preliminary stage. Zhang et al. Prepared semi-solid slurry of az91-2wt.% CA alloy by bubble stirring process, and then carried out squeeze casting.

The results show that the primary α – Mg, β – mg12al12 and al2ca phases in the rheo squeeze casting alloy are refined, and the room temperature tensile yield strength, tensile strength and elongation of the alloy are increased by 48.3%, 39.1% and 106.2% compared with those of the metal mold casting alloy, and by 27%, 22.8% and 83.3% compared with those of the squeeze casting alloy, respectively. The semi-solid slurry of Mg – re (65% Ce and 35% LA) – Zn – y alloy was prepared by ultrasonic and squeeze casting. The results show that with the increase of pressure, the microstructure of the alloy is refined, the solubility of solute atoms in α – Mg is increased, the rare earth rich phase is evenly distributed along the grain boundaries, and the mechanical properties are gradually improved.

The rheo squeeze casting mg-9al-zn alloy was studied by Guo et al. It is found that the rheo squeeze casting process can obtain complete castings. Compared with the conventional squeeze casting alloy, the microstructure of rheo squeeze casting alloy is fine, the second phase is evenly distributed, and the casting defects are reduced, so the mechanical properties of rheo squeeze casting alloy are relatively high. In addition, the solid fraction of semi-solid slurry determines the α – Mg grain size, the distribution and volume fraction of β – mg12al12 phase, which affects the mechanical properties of the alloy.