Solid-solution pre-treatment method for improving strength and plasticity and toughness of aluminum lithium alloy thin sheet and heat treatment method thereof

Abstract

The invention provides a solid-solution pre-treatment method for improving strength and plasticity and toughness of an aluminum lithium alloy thin sheet. The method is characterized in that the solid-solution pretreatment is carried out on the aluminum lithium alloy in a temperature increase rate controlling manner, wherein the temperature increase rate of the solid-solution pre-treatment is 2 to 15 DEG C per minute; the initial temperature in temperature increase of the solid-solution pre-treatment is 20 to 25 DEG C, and the end temperature in the temperature increase of the solid-solution pre-treatment is 500 to 510 DEG C. According to the solid-solution treatment method, the aluminum lithium alloy is treated by temperature increase at the rate of 2 to 15 DEG C per minute, thus influencing the form and distribution of recrystallized grain to generate a textured structure form. Therefore, the comprehensive mechanical property of the aluminum lithium alloy thin sheet can be improved, and the strength and the plasticity and toughness can be improved.

Description

technical field [0001] The invention relates to the technical field of aluminum-lithium alloys, in particular to a solid-solution pretreatment method for improving the strong plasticity of aluminum-lithium alloy thin plates and a heat treatment method thereof. Background technique [0002] The strong plasticity of metal refers to the simultaneous improvement of the strength and plasticity of the material after cold processing or heat treatment. [0003] Al-Li alloys have become the most ideal structural materials for aerospace due to their low density and excellent mechanical properties. According to the application requirements of different aerospace backgrounds, designing aluminum-lithium alloys with different properties is the development direction of aluminum-lithium alloys. Use the comprehensive mechanical properties of materials or reduce the density of aluminum-lithium alloys through structural weight reduction, reduce rocket launch costs, increase thrust-to-weight r...

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Problems solved by technology

[0004] With the development of application requirements and the improvement of metallurgical technology, aluminum-lithium alloys have experienced three stages of development, of which the first stage spans from the 1950s to the 1960s. The alloy was applied to the wing skin and tail level stabilizer of the early warning aircraft, achieving a weight reduction of 6%, but the level of plasticity and toughness was too low; the second stage spanned from the 1970s to the late 1980s, with 1420 Alloys are low-density, medium-strength, damage-resistant, and high-strength aluminum-lithium alloys, but there are problems with severe alloy anisotropy and low levels of plasticity and toughness; the third stage began in the 1990s, with high-strength weldable The 1460 alloy and the low-anisotropy AF / C-489 alloy are represented by alloys with special advantages in a certain aspect. At present, the fourth generation of aluminum-lithium alloys is being developed internationally, hoping to improve the alloy's strong plasticity and toughness in a targeted manner. and molding performance

[0005] With the development of the aerospace industry, the demand for weight reduction and enhancement of aluminum-lithium alloys is increasing, but the strength and plastic toughness of aluminum-lithium alloys processed by existing technologies cannot meet the higher mechanical requirements of aluminum-lithium alloys in the aerospace industry. Performance requirements limit the wide application of aluminum-lithium alloys in the aerospace field

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