Aluminum alloy containing beta ''phase and theta 'phase simultaneously and preparation method thereof

The invention relates to an aluminum alloy simultaneously containing a beta ''phase and a theta 'phase and a preparation method thereof, and belongs to the technical field of aluminum and aluminum alloy casting. According to the method, the strength of the aluminum alloy (especially the ZL114A aluminum alloy) is improved through beta ''phase and theta 'phase synergistic strengthening for the first time. The preparation method provided by the invention comprises the following steps: smelting a ZL114A alloy, and adding 0.33-0.55 wt% of Cu into the ZL114A alloy; casting a resin sand mold to obtain a cast ingot, carrying out solution treatment on the cast ingot, quenching after solution treatment, and then carrying out artificial aging treatment to obtain a product; the aging temperature of the artificial aging is 163-185 DEG C, and the heat preservation time is 7-12 hours. According to the method, the strengthening effect of Cu in the ZL114A alloy can be fully exerted, the phenomenon of beta ''phase and theta 'p