Al-Zn-Mg-Cr-Mn-Zr-Er medium-strength and high-toughness aluminum alloy plate and preparation method thereof

Abstract

The invention discloses a preparation method of an Al-Zn-Mg-Cr-Mn-Zr-Er medium-strength and high-toughness aluminum alloy plate. The Al-Zn-Mg-Cr-Mn-Zr-Er medium-strength and high-toughness aluminum alloy plate is prepared from the alloy components: 3.0-4.0% of Zn, 1-2% of Mg, 0.2-0.4% of Mn, 0.1-0.3% of Cr, 0.1-0.3% of Zr, 0.1-0.3% of Er, 0.1-0.5% of Si, less than 0.01% of Cu and the balance of Aland other impurities, and the content of single impurity is not more than 0.1%. The preparation process includes the steps that an alloy prepared according to the composition design is smelted, casted and poured into an ingot with a diameter of 300 mm to 500 mm, the temperature is directly raised to 460 DEG C without homogenization heat treatment after stress relief annealing of the ingot is completed at 220 DEG C to 300 DEG C, after temperature is kept for 3 to 6 hours, hot extruding is carried out, and an aluminum alloy plate with a thickness of 6 to 10 mm is prepared under the condition that the extrusion ratio exceeds 16, wherein the extruded aluminum alloy plate has the tensile strength of more than 350 Mp, the yield strength of more than 300 Mp, the elongation of more than 15% and the ISSRT of less than 0.03 at normal temperature after solid solution aging treatment.

Description

technical field [0001] The invention belongs to the preparation of aluminum alloy plates and belongs to the technical field of preparation and processing of light metal materials, in particular to an Al-Zn-Mg-Cr-Mn-Zr-Er medium-strength and high-toughness aluminum alloy plate and a preparation method thereof. Background technique [0002] At present, the closest existing technology: 7-series aluminum alloys are mainly composed of Zn and alloying elements. According to the performance requirements of the alloy, it is also necessary to add an appropriate amount of Cu and Mg. Therefore, the so-called 7-series aluminum alloys are mainly Al - Zn-Mg-Cu alloy. At present, due to the advantages of low density, high strength and easy processing and forming, the 7-series aluminum alloy has been widely used in the fields of transportation and aerospace. [0003] With the world's high standards for energy and the environment, in order to achieve energy conservation and environmental pr...

AI Technical Summary

Problems solved by technology

[0005] To sum up, the problems existing in the existing technology are: the composition of the aluminum alloy needs to be continuously optimized, the alloy composition of the medium-strength and high-toughness aluminum alloy needs to be further optimized, the development of Cu-free, low-Zn medium-strength and high-toughness 7-series aluminum alloy varieties, adding Trace rare earth and transition group elements, control the proportion of microalloying elements, and obtain high-performance medium-strength and high-toughness 7-series aluminum alloy sheets

The alloy production process is complex and the production efficiency is relatively low, especially the homogenization heat treatment, which takes a long time. Therefore, it is necessary to continue to discuss the preparation process, optimize the heat treatment system, improve production efficiency, and achieve energy conservation and environmental protection on the basis of optimizing alloy elements.

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