ALUMINUM ALLOY PRODUCT ADAPTED TO PRODUCE STRUCTURE PIECE AND PRODUCING METHOD THEREOF

摘要

An aluminium alloy product for manufacturing structural components, made from direct chill casting ingots comprises, based on wt%: Zn 7.5 ˆ¼ 8.7, Mg 1.1 ˆ¼ 2.3, Cu 0.5 ˆ¼ 1.9, Zr 0.03 ˆ¼ 0.20, the balance being Al, incidental elements and impurities, wherein the levels of Zn, Mg, Cu, and Zr in the aluminum alloy products satisfy the expressions of (a) 10.5 ‰¤ Zn + Mg + Cu ‰¤11.0; (b) 5.3 < (Zn / Mg) + Cu ‰¤ 6.0; and (c) (0.24 - D / 4800) ‰¤ Zr ‰¤ (0.24 - D / 5000), wherein D is the minimum length of a line section connecting any two points on the periphery of the cross section of the ingot and passing through the geometrical center of the cross section, and 250 mm ‰¤ D ‰¤ 1000 mm. The aluminum alloy products have a superior combination of strength and damage tolerance, and exhibit homogeneous and consistent performance on the surface, at various depths under the surface, and in the core of the product. The present invention further provides a method of producing the aluminum alloy products.