A kind of heat treatment method of al-cu-li alloy pre-aging re-solution re-aging

Abstract

The invention discloses a heat treatment method for Al-Cu-Li alloy pre-aging, re-solution and re-aging, which belongs to the field of material heat treatment. Starting from controlling the heat treatment process system and its parameters, the Al-Cu-Li alloy extruded plate is conventionally Solution, pre-aging, heavy solution and re-aging treatments. The conventional solid solution and heavy solution treatment temperature is 515±10°C, heat preservation for 60-90 minutes, and then water quenching, and the quenching transfer time is <5s. The temperature for pre-aging and re-aging treatment is 160-180°C, keep warm for 24-48 hours, and air-cool after taking it out. Re-solution treatment can reduce the strength of the alloy, improve the plasticity of the alloy, and is beneficial to the orthopedic and reprocessing processes; re-aging treatment can effectively control the type, density and distribution of precipitates, and improve the strength of the alloy. Coupled with the coarsening of discontinuous grain boundary precipitates and the increase of copper content in the alloy, the performance of stress corrosion resistance, intergranular corrosion and electrochemical corrosion is improved under the premise of maintaining the strength of the alloy. Increased plasticity. The process is simple and easy and is not limited by the thickness of the plate.

Description

technical field [0001] The invention relates to a heat treatment method for Al-Cu-Li alloy pre-aging heavy solution re-aging, which belongs to the technical field of metal material heat treatment, in particular to the technical field of aluminum alloy heat treatment. Background technique [0002] The information disclosed in this background section is only intended to increase the understanding of the general background of the present invention, and is not necessarily taken as an acknowledgment or any form of suggestion that the information constitutes the prior art already known to those skilled in the art. [0003] As an emerging lightweight alloy material, Al-Cu-Li alloy has been favored for its high elastic modulus, high specific strength and specific stiffness, high damage tolerance, low density, and good weldability. Widely used in aviation, aerospace and military fields, it has become the main substitute material for 2xxx and 7xxx series aluminum alloys. [0004] Al-...

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Problems solved by technology

However, the inventors found that the alloy used in this research has undergone pre-stretch deformation treatment, and the alloy has been subjected to pre-stretch deformation again during the re-aging process. Although the performance of the alloy can be improved, in the actual application process, the pre-deformation will change. The initial shape of the structural parts affects the dimensional accuracy of the structural parts, which may make the structural parts unusable, so the aging treatment system is not practical for structural parts in practical applications

In addition, the aging system does not indicate its role in balancing the strength and corrosion resistance of the alloy, and does not analyze and study the stress corrosion resistance and electrochemical corrosion resistance of the alloy after the process, nor does it give information about the crystal Mechanistic Explanation of the Characteristic Evolution of Boundary Precipitated Phases

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