Gd-Lu-containing aluminum alloy section bar for space flight and aviation and preparation method thereof

Abstract

The invention discloses a Gd-Lu-containing aluminum alloy section bar for space flight and aviation and a preparation method thereof. The Gd-Lu-containing aluminum alloy section bar comprises, by weight, 5.2-6.4% of Zn, 1.8-2.6% of Mg, 1.5-2.0% of Cu, 0.3-0.6% of Mn, 0.25-0.35% of Cr, 0.1-0.3% of Si, 0.15-0.25% of Fe, 0.05-0.1% of Ti, 0.04-0.08% of Zr, 0.2-0.4% of Gd, 0.1-0.2% of Lu and the balance Al. Gd and Lu rare earth elements are added into an Al-Zn-Mg-Cu series aluminum alloy and through alloying, alloy as-cast grains are refined, strengthening phase precipitation density is improved, strengthening phase distribution is uniform, recrystallization is inhibited, crystal boundary movement is prevented, re-crystal grain growth is inhibited, alloy strength is substantially improved and stress corrosion resistance and welding performances of the alloy are improved. Gd and Lu replace Sc and are added in the Al-Zn-Mg-Cu series aluminum alloy so that a production cost is not greatly improved and alloy strength is greatly improved. The Gd-Lu-containing aluminum alloy section bar can be widely used in the field of space flight and aviation.

Description

technical field [0001] The invention relates to an aluminum alloy profile containing Gd and Lu for aerospace and a preparation method thereof, belonging to the field of aluminum alloy materials. Background technique [0002] Al-Zn-Mg-Cu series aluminum alloy belongs to ultra-high-strength deformed aluminum alloy, which has the advantages of high specific strength and specific stiffness, good corrosion resistance and high toughness, and is one of the most important structural materials in the aviation field. . With the continuous development of aerospace technology, the requirements for its strength are getting higher and higher. At present, most Al-Zn-Mg-Cu aluminum alloys use the addition of rare earth element Sc instead of Zr, or compound addition of (Sc+Zr) elements, which can not only inhibit recrystallization, form a very fine and dispersed substructure, but also strengthen through precipitation. Therefore, the strength of the alloy is greatly increased, and various p...

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Problems solved by technology

At present, most Al-Zn-Mg-Cu aluminum alloys use the addition of rare earth element Sc instead of Zr, or compound addition of (Sc+Zr) elements, which can not only inhibit recrystallization, form a very fine and dispersed substructure, but also strengthen through precipitation. It can greatly increase the strength of the alloy and improve various properties of the alloy, but there is no report on the simultaneous application of Gd and Lu in Al-Zn-Mg-Cu aluminum alloys