Aluminum alloy extruded sectional material at grade of 700 MPa

Abstract

The invention provides an aluminum alloy extruded sectional material at the grade of 700 MPa. The sectional material is composed of, by weight, 7.8%-10.3% of Zn, 1.3%-2.0% of Mg, 1.3%-2.0% of Cu, 0.08%-0.15% of Zr, 0-0.15% of Si, 0-0.15% of Fe, 0-0.05% of other single impurities, 0-0.15% of other impurities, and the balance Al. The alloy components are subjected to burdening. The raw materials are melted and poured to form alloy ingots with required specifications after furnace refining and standing. The alloy ingots are subjected to an optimal extrusion technique to be formed after optimized three-grade homogenization, and the alloy ingots can be used for machining parts after heat treatment. The novel aluminum alloy extruded sectional material is even in microscopic structure and stable in performance; the ultimate tensile strength can be over 700 MPa, and meanwhile the elongation rate is higher than 8% and the fracture toughness is up to 26 MPa.m<1/2>, so that the requirement for aerospace material selection at present is met, and the aluminum alloy extruded sectional material can be widely applied to the fields of nuclear industry, transportation, weapons and the like at the same time.

Description

technical field [0001] The invention relates to an aluminum alloy extruded profile, in particular to a 700MPa grade aluminum alloy extruded profile. Background technique [0002] In recent years, with the improvement of aluminum metallurgical equipment technology and metallurgical basic technology, high purification and high alloying have made it possible to manufacture 600MPa aluminum alloys through traditional melting and casting technology, and have been industrialized. Aluminum alloys include 7150 aluminum alloy (Al-7.6%Zn-1.8%Mg-2.0%Cu-0.10%Zr), 7055 aluminum alloy (Al-8%Zn-2.0%Mg-2.2%Cu-0.10%Zr) and the like. [0003] At present, the powder metallurgy method can also produce aluminum alloys above 700MPa, or even 800MPa, but it is difficult for industrial application due to various conditions. At present, some domestic patent documents can also produce aluminum alloys above 700MPa by adding high-content Zn elements and T77 three-stage aging process. If the Zn content e...

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Problems solved by technology

[0003] At present, the powder metallurgy method can also produce aluminum alloys above 700MPa, or even 800MPa, but it is difficult for industrial application due to various conditions.

At present, some domestic patent documents can also produce aluminum alloys above 700MPa by adding high-content Zn elements and T77 three-stage aging process. If the Zn content exceeds 10%, there is a problem that the ingot is easy to crack and difficult to form. Realize industrial application

In addition to the difficulty of ingot forming in high alloying, a lot of coarse non-equilibrium eutectic phases will be formed in the grain and grain boundaries. It is difficult to completely eliminate them by traditional homogenization and solid solution processes, and it is also difficult to obtain alloy properties. big improvement

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