(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 通过硬度测试、拉伸测试、透射电镜分析以及织构测试等手段，研究拉伸和冷轧两种不同预变形方式对2519A铝合金165 ℃时效后组织与力学性能的影响。结果表明：适当的变形量均使θ′相尺寸细小、密度增加，而变形量过大使θ′相分布变得较不均匀，合金强度提高不大，而塑性降低；6%拉伸预变形和7%冷轧预变形使合金板材峰值时效抗拉强度、屈服强度和伸长率分别为472 MPa、404 MPa、15.6%和472 MPa、417 MPa、9.4%，二者的抗拉强度基本相同，但前者的屈服强度低、塑性高；两种预变形方式下板材织构类型相同，取向密度无明显差别；合金板材屈服强度和伸长率的差别由第二相θ′相的数量、尺寸和分布所确定。
关键字: 铝合金；2519A铝合金；拉伸预变形；冷轧预变形；力学性能；显微组织；织构
microstructures and mechanical properties of 2519A aluminum alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of stretching and rolling pre-deformation on the microstructures and mechanical properties of 2519A alloy plate aged at 165 ℃ were investigated by hardness test, tensile test, transmission electron microscopy(TEM) and texture measurement. The results show that for both of the pre-deformation methods, proper pre-deformation leads to the quantity increasing and refinement of θ′ phase. But the inordinate deformation leads to an inhomogeneous distribution of θ′ phase, which decreases the elongation. For the 6% pre-stretching elongation and 7% pre-cold cooling deformation, the tensile strength, yield strength and elongation are 472 MPa, 404 MPa, 15.6% and 472 MPa, 417 MPa, 9.4%, respectively. Both of their tensile strengths are equivalent, but the yield strength of the pre-stretched alloy plate is lower, while the elongation is higher. The texture components and orientation density of the pre-stretched and pre-rolled alloy plates are almost the same, therefore, the yield strength of the alloy plate is determined by the quantity, size and θ ′ phase distribution.
Key words: aluminum alloy; 2519A aluminum alloy; pre-stretching; cold rolling pre-deformation; mechanical properties; microstructure; texture
