拉伸与轧制预变形对2519A铝合金组织与力学性能的影响

Effects of stretching and rolling pre-deformation on microstructures and mechanical properties of 2519A aluminum alloy

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472MPa、404MPa、15.6%和472MPa、417MPa、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。

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 ofθ′phase.But the inordinate deformation leads to an inhomogeneous distribution ofθ′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 andθ′phase distribution.