High-strength high-heat-resistance low-scandium sliver added Al-Cu-Mg-series alloy and thermal treatment process thereof

Abstract

The invention discloses a high-strength high-heat-resistance low-scandium sliver added Al-Cu-Mg-series alloy and a thermal treatment process thereof. Cu and Mg in the alloy are main alloyed elements;Sc, Zr, Si, Ag, Ti, Mn and V are micro-alloyed elements; mass percentage content of Fe in impurities is properly broadened, and the rest of impurities including Ni and Zr need to strictly control; forthe alloy with Mg content greater than 0.3%, thermal deformation is performed before homogenization to avoid hot cracking tendency, and then homogenization is performed again. Ageing treatment comprises combination of natural ageing and artificial ageing; a micro structure and strength are improved by relevance of cluster-precipitation behaviors; and while usage amount of dear scandium and sliverelements is controlled to be smaller than 0.2%, room-temperature tensile strength of the target alloy can be higher than 470 MPa, and tensile strength at a temperature of 300 DEG C and a temperatureof 400 DEG C is separately greater than 160 MPa and 100 MPa.

Description

technical field [0001] The invention relates to the technical field of nonferrous metals, in particular to a high-strength and high-heat-resistant low-scandium silver Al-Cu-Mg alloy and a heat treatment process thereof. Background technique [0002] 2xxx series (Al-Cu) alloys, as a typical representative of age-strengthable aluminum alloys, have excellent comprehensive mechanical properties, and are generally considered to be a series of better heat resistance among aluminum-based alloys. Usually, different contents of Mg need to be added to 2xxx series alloys to improve their age hardening properties. Taking the classic 2024 alloy as an example, its main alloying elements include Cu: 3.8%-4.9%, Mg: 1.2%-1.8%, and other elements such as Mn and Si. The main role of Mg in it is to combine with Cu to form Cu-Mg co-clusters to make the alloy harden rapidly during natural aging, or to combine the supersaturated solid solution (SS) of the Al-Cu binary system—GPB zones— The θ”—θ’...

AI Technical Summary

Problems solved by technology

However, although the use of elements such as Ag and Sc can effectively improve the performance, its expensive addition cost prohibits most commercial aluminum alloys.

At the same time, the preliminary research work on heat-resistant Al-Cu-Mg-Ag-based alloys and Al-Sc-based alloys has been carried out abroad for more than ten years, and a large amount of data and technical experience have not been disclosed.

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