Preparation method of al-cu-li-x aluminum-lithium alloy surface delithiation layer

Abstract

The invention discloses a preparation method of a surface deintercalation layer of an Al-Cu-Li-X aluminium-lithium alloy. According to the method, by using a principle that lithium elements on the near-surface layer of the aluminium-lithium alloy are diffused to the surface of the alloy to carry out oxidization in the process of high-temperature heating, and a uniform deintercalation layer is formed on the near-surface layer of the alloy through controlling the heating temperature and the heat preservation time, so that the intergranular corrosion and the occurrence of exfoliation corrosion are effectively inhibited on the premise of not affecting the mechanical properties; and the method is also a necessary process of surface aluminium-clad rolling for aluminium alloys. The method comprises the steps of low-temperature long-period heat-preservation deintercalation treatment; and high-temperature solution treatment. An applicable aluminium-lithium alloy disclosed by the invention comprises the following components by weight percent: 2.0-5.0% of Cu, 0.8-2.5% of Li, 0.20-0.60% of Mn, 0.20-0.80% of Zn, 0.04-0.20% of Zr, 0.20-0.80% of Mg, 0.1-0.7% of Ag, less than or equal to 0.10% of Si, less than or equal to 0.10% of Fe, less than or equal to 0.12% of Ti, less than or equal to 0.05% of other single impurities, less than or equal to 0.15% of total impurities, and the balance of Al. According to the method, the corrosion resistance of Al-Cu-Li-X series alloys can be significantly improved.

Description

technical field [0001] The invention relates to a method for preparing a delithiated layer on the surface of an Al-Cu-Li-X aluminum-lithium alloy, which belongs to the surface treatment technology of an aluminum alloy. layer, so that the corrosion resistance of the alloy is improved. Background technique [0002] Al-Cu-Li-X series age-strengthened aluminum-lithium alloy has the characteristics of damage resistance, high specific strength and high specific modulus. By adopting special pre-stretching and heat treatment processes, good strength, fracture toughness and durability can be obtained. Corrosion and damage resistance and other comprehensive properties have increasingly become a hot spot in the research and development of aluminum-lithium alloys at home and abroad. Among them, T3 and T4 state thin plates have excellent formability and damage resistance and are regarded as the most potential aircraft skin materials, but the alloys in these two states have a certain ten...

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Problems solved by technology

Among them, T3 and T4 state thin plates have excellent formability and damage resistance and are regarded as the most potential aircraft skin materials, but the alloys in these two states have a certain tendency of intergranular corrosion. The preferred T8 state is used instead of the T3 / T4 state. Because the T8 treatment has higher requirements on the amount of pre-stretch deformation and aging process, and the formability and damage resistance of the T8 state are much lower than that of the T3 / T4 state, which limits the thin plate as a mask. Application of leather material

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