一种新型超高强铝锂合金板材的组织与力学性能

Structures and Mechanical properties of a super-high strength Al-Li alloy

摘要:

研究了课题组开发的一种新型超高强铝锂合金的组织与力学性能。结果表明：该合金具有优异的常规力学性能,典型T8热处理时抗拉强度600 MPa以上,延伸率超过10%。10 mm厚热轧板材及2 mm厚冷轧薄板T8峰时效(150oC)时析出强化相相均为T1相(Al2CuLi)与q￠相(Al₂Cu),且两种厚度板材中析出相分数和尺寸均相当,但10 mm厚热轧板材T8峰时效抗拉强度比2 mm厚冷轧薄板高50~70 MPa左右。力学性能的差异主要来源于固溶处理后变形织构分数的不同；经固溶处理后10 mm厚热轧板材变形织构体积分数远高于2 mm冷轧薄板。

关键词:铝锂合金;强度;微观组织;织构

Abstract:

The structures and mechanical properties of a new super-high strength Al-Li alloy developed by this group were investigated. The alloy possessed excellent properties, of which the tensile strength was greater than 600 MPa, and the elongation higher than 10%. After T8 aging, the strengthening precipitates in both cold-rolled sheet with 2 mm thickness and hot-rolled plate with 10 mm thickness were T1(Al₂CuLi) and q￠(Al₂Cu), and their fraction and size were basically same in the two plates with different thickness. The strength of T8-aged plate with 10 mm thickness was 50~70 MPa higher than that the T8-aged sheet with 2 mm thickness. This strength enhancement was originated from the texture fraction after solution treatment. The volume fraction of the deformation texture in the solutionized hot-rolled plate with 10 mm thickness was much higher.

Key words:Al-Li alloy; strength; micro-structure; deformation texture