HIGH-STRENGTH ALUMINUM ALLOY FOR ELECTRONIC PRODUCT OUTER PARTS AND PREPARATION METHOD FOR HIGH-STRENGTH ALUMINUM ALLOY

摘要

A high-strength aluminum alloy for electronic product outer parts and a preparation method for the high-strength aluminum alloy. The aluminum alloy is prepared from the following components according to the mass percent: 4.5-5.5% of Zn, 0.8-1.0% of Mg, 0.3-0.5% of Cu, 0.05-0.15% of Mn, 0.01-0.03% of Y, 0.04-0.06% of Ti, 0.005-0.01% of Sr, less than or equal to 0.1% of Fe, less than or equal to 0.1% of Si, and the balance of Al and inevitable other impurities. The preparation method comprises the steps of preparing an aluminum alloy solution by smelting, performing spraying and refining in a furnace, performing online refinement and modification, performing online degassing and filtration, performing semi-continuous casting, homogenizing cast ingots, heating and extruding, and performing online quenching and artificial aging. According to the method, the cleanliness of the aluminum alloy and the uniformity of compositions are increased, Fe-enriched phases and continuous intercrystalline reticular MgZn₂ phases are refined and modified, and the defects of black lines, black dots and the like of an oxidation film are eliminated, so that recrystallized fine equiaxed grains are obtained by extruding the aluminum alloy, textural stripes and piebald of the oxidation film are eliminated, and the quality of the oxidation film is improved. The aluminum alloy has high strength, good plasticity, and excellent oxidizing and coloring effects, and is suitable for manufacturing outer structural parts of various electronic products.