冷变形对2219铝合金环轧件组织和力学性能的影响

Effect of Cold-Deformation on Mechanical Property and Microstructure of 2219 Aluminum Alloy Ring Rolled Pieces

摘要: 本文采用维氏硬度计、拉伸力学性能测试，透射电镜(TEM)、扫描电镜(SEM)等实验分析手段，研究了2219环轧件在不同冷变形条件下的组织和力学性能。结果表明：随着冷变形程度的增加，合金达到峰值时效的时间明显缩短，其峰值硬度逐渐增加；材料的抗拉强度和屈服极限随时冷变形量的增加先增加后略微下降，冷变形量为3%时性能最佳，抗拉强度为426.54 MPa (轴向)、436.62 MPa (切向)、445.67 MPa (径向)和屈服强度为323.88 MPa (轴向)、334.35 MPa (切向)、336.72 MPa (径向)；随着冷变形量的增加，合金塑性整体呈下降趋势，以切向降低最为显著。随着冷变形程度的增加，合金析出相逐渐增长加厚，第二相粒子位错运动机制由切过机制转换为绕过机制。综合考虑，当变形量为3%时性能最佳。

Abstract: The effect of cold-deformation about 2219 aluminum alloy ring rolled pieces was investigated by Vicker hardness TEM, SEM, and mechanical testing. Study shows that hardness and time of peak-aging gradually increase following the adding of cold-deformation. Yield strength or tensile strength increases firstly and then maintains as the cold-deformation adding. At deformation 3%, it has best properties with the tensile strength: 426.52 MPa (axial direction), 436.62 MPa (tangent direction) and 445.67 MPa (radial direction), and yield strength: 323.88 MPa (axial direction), 334.35 MPa (tangent direction), 336.72 MPa (radial direction). The elongation will decrease along with the cold-deformation adding, which is particularly significant along tangent direction. As cold-defor- mation increases, precipitation of alloy becomes longer and wider, the mechanism of dislocation changes to Orowan from the cross precipitation. In general, forge pieces have best prop-erties at 3% deformation.