Two-stage forced solution treatment method for high strength deformed aluminum alloy

Abstract

This invention discloses a double-stage forced solutionizing method for manufacturing a high-strength flexible alumina alloy. The method comprises the steps of: (1) performing a first stage solutionizing method at 430-460 deg.C for 1-3 h; and (2) performing a second stage solutionizing method at 460-500 deg.C for 1-3 h. The method can ensure the remelting of the precipitated phase during performing and hot-pressing processes, while recystallization and crystal grain growth can be avoided. Therefore, the precipitated phase can be uniform and fine during the subsequent aging treatment. The alumina alloy manufactured by this method has improved ultimate tensile strength and yield strength (by 3-10%), elongation percentage (by 1-5%), fracture ductility, fatigue resistance and stress corrosion resistance.

Description

technical field [0001] The invention relates to a two-stage forced solid solution treatment method suitable for high-strength deformed aluminum alloys, especially high-alloyed high-strength deformed aluminum alloys. Background technique [0002] 7xxx series high-strength deformed aluminum alloy is AlZnMgCu series aluminum alloy, which is the highest strength aluminum alloy, so it is also called ultra-high-strength aluminum alloy, and it is also a typical aging-strengthened aluminum alloy. Only through reasonable heat treatment can a large amount of precipitation be formed in the alloy Phases can achieve the purpose of strengthening and toughening. High-strength aluminum alloys are mainly strengthened through aging precipitation. The increase in the degree of supersaturation will increase the number of aging precipitation phases and increase the strengthening effect. [0003] The heat treatment process has a great influence on the properties of the alloy, especially the stren...

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Problems solved by technology

Its purpose is to make the material reach the limit of strength, but the 7075 or B95 alloy aged to the maximum strength exposes some fatal shortcomings during use: resistance to stress corrosion cracking, resistance to exfoliation corrosion and low fracture toughness (sensitive to stress concentration ), resulting in poor reliability of the material

When the material undergoes solution treatment, if the temperature exceeds the melting point or solidus temperature of the low-melting eutectic phase, it is prone to overburning, resulting in a decrease in material performance

However, the low-melting eutectic phase in the material is a multi-phase eutectic combination phase. At high temperature, the dissolution thermodynamics and kinetic conditions of each phase are different, and each phase will not dissolve back at the same time, but there is a certain order of dissolution back. When After a certain phase in the low-melting eutectic phase is completely dissolved, the eutectic temperature of the remaining eutectic phase will increase. At this time, even if the temperature reaches or exceeds the melting point of the initial low-melting eutectic phase, eutectic remelting will not occur, and The traditional single-stage solid solution system is difficult to fully dissolve the precipitated phases in the alloy structure, thus affecting the properties of the material

[0009] In recent years, some researchers have conducted research on continuous temperature rise solution treatment, but in industrial production due to continuous production and energy saving requirements, it is difficult to achieve continuous temperature rise treatment, so it has not been practically applied

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