Al-Mg-Si-RE aluminum alloy and preparation method thereof

The invention provides an Al-Mg-Si-RE aluminum alloy, which is prepared from the following components in percentage by mass: 0.25 to 0.45 percent of Mg, 6.5 to 7.5 percent of Si, 0.0055 to 0.1 percent of RE, 0.1 to 0.2 percent of Be, 0.05 to 0.5 percent of a refiner and 90 to 93.0 percent of Al, and the refiner is at least one of Ti, C and B. The Al-Mg-Si-RE aluminum alloy has the advantages that the Al-Mg-Si-RE aluminum alloy is prepared from the following components in percentage by mass: 1 percent of Al, 1 percent of Mg, 1 percent of Si, 1 percent of RE, 0.1 to 0.2 percent of Be, 0.05 to 0.5 percent of a refiner and 90 to 93.0 percent of Al; the invention further provides a preparation method of the Al-Mg-Si-RE aluminum alloy. After the Al-Mg-Si-RE aluminum alloy is subjected to heat treatment, the Al-Mg-Si-RE aluminum alloy can obtain extremely high tensile strength and elongation percentage, namely tensile strength gt; the ductility is gt under the pressure of 370 MPa; 8%. In GB T 1173-2013, after T6 is