Aluminum-lithium alloy and heat treatment process thereof

Abstract

The invention provides an aluminum-lithium alloy and a heat treatment process thereof, the aluminum-lithium alloy is an alloy with a high Cu/Li ratio, and the heat treatment process is two-stage homogenization heat treatment. The first-stage homogenization heating rate of the two-stage homogenization heat treatment is 8-12 DEG C/min, the homogenization temperature is 465-480 DEG C, the heat preservation time is 14-18 h, the second-stage homogenization heating rate is 3-5 DEG C/min, the homogenization temperature is 490-505 DEG C, and the heat preservation time is 20-30 h; after two-stage homogenization heat treatment, the volume fraction of residual phases in the aluminum-lithium alloy does not exceed 0.7%, and the residual phases are Al-Cu-Fe-Mn phases with high melting points, so that low-melting-point phases in an aluminum-lithium alloy ingot are eliminated to the greatest extent, a uniform fire state structure with uniformly distributed alloy elements is obtained, and the subsequent processing performance is improved.

Description

technical field [0001] The invention relates to the technical field of aluminum-lithium alloy and heat treatment thereof, in particular to an aluminum-lithium alloy and a homogenization heat treatment process thereof. Background technique [0002] Aluminum-lithium alloy has a huge market prospect in the field of aviation and aerospace because of its light weight and high strength. Adding Cu element in aluminum-lithium alloy will lead to weight increase of aluminum-lithium alloy, but it can improve the comprehensive performance of aluminum-lithium alloy and make the application prospect more broad. With the increase of Cu element content, the composition segregation of the ingot intensifies, and the volume fraction of the primary phase increases. How to better eliminate the composition segregation and dissolve the low melting point phase through proper homogenization annealing has become an urgent problem to be solved in the development of aluminum-lithium alloys in my countr...

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Problems solved by technology

[0003] The patent with the publication number CN 112831736 A discloses a two-stage homogenization annealing process for 2099 Al-Li alloy, which preferably eliminates the primary phase in the 2099 Al-Li alloy ingot. However, in this technical solution, the 2099 Al-Li alloy is cast The Cu content of the ingot is low, and the relevant heat treatment system is not suitable for Al-Li alloys with high Cu content

[0004] The patent with the publication number CN 112281035 B discloses a method for preparing an alloy with excellent comprehensive performance. The uniform heat treatment system is carried out at 510°C-530°C for 70-80h. However, the long-term high-temperature heat treatment increases energy consumption, and then increase carbon emissions

[0005] The patent with the publication number CN 109666830 B discloses a deformed aluminum-lithium-copper-zinc alloy and its preparation method. Single-stage homogenization heat treatment at 500°C for 36 hours cannot guarantee the homogenization effect. In addition, the Cu / Li ratio is small, the primary phase is less, and its heat treatment process is not suitable for aluminum-lithium alloys with higher Cu / Li ratio

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