(中南大學 材料科學與工程學院，長沙 410083)
摘 要: 通過硬度測試、拉伸測試、透射電鏡分析以及織構(gòu)測試等手段，研究拉伸和冷軋兩種不同預變形方式對2519A鋁合金165 ℃時效后組織與力學性能的影響。結(jié)果表明：適當?shù)淖冃瘟烤功取湎喑叽缂毿 ⒚芏仍黾樱冃瘟窟^大使θ′相分布變得較不均勻，合金強度提高不大，而塑性降低；6%拉伸預變形和7%冷軋預變形使合金板材峰值時效抗拉強度、屈服強度和伸長率分別為472 MPa、404 MPa、15.6%和472 MPa、417 MPa、9.4%，二者的抗拉強度基本相同，但前者的屈服強度低、塑性高；兩種預變形方式下板材織構(gòu)類型相同，取向密度無明顯差別；合金板材屈服強度和伸長率的差別由第二相θ′相的數(shù)量、尺寸和分布所確定。
關(guān)鍵字: 鋁合金；2519A鋁合金；拉伸預變形；冷軋預變形；力學性能；顯微組織；織構(gòu)
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
