Rare-earth aluminum alloy and preparation method thereof

The invention provides a rare earth aluminum alloy and a preparation method of the rare earth aluminum alloy. The rare earth aluminum alloy comprises the following compositions in percentage by weight: 0.7-1.3 wt percent of Si, 0.4-1.0 wt percent of Mn, 0.6-1.2 wt percent of Mg, 0.1-0.2 wt percent of Re, Fe larger than 0 wt percent and no more than 0.5 wt percent, Cr larger than 0 wt percent and no more than 0.25 wt percent, Zn larger than 0 wt percent and no more than 0.2 wt percent, Ti larger than 0 wt percent and no more than 0.1 wt percent, Cu larger than 0 wt percent and no more than 0.1 wt percent and the balance of aluminum. According to the rare earth aluminum alloy provided by the invention, because a small number of rare earth elements are added in an aluminum alloy and can have stronger affinity with gas and many nonmetals, and a compound with high melting point is produced, the rare earth aluminum alloy has the certain actions of dehydrogenation, refining and purification; and meanwhile, the rare earth elements can also be selectively adsorbed to an interface of a grown crystal grain to block the growth of the crystal grain and enable the crystal grain to be refined, thus strengthening the strength of the aluminum alloy and improving the processing performance of the aluminum alloy.