2519铝合金的低温拉伸力学性能

利用拉伸测试、扫描电镜与透射电镜等手段，研究室温和液氮温度下2519铝合金板材的拉伸力学性能。研究结果表明：当变形温度由293K降至77K时，合金纵向抗拉强度由493．64MPa升至607．35MPa，提高了23．1％，屈服强度由454．83MPa上升到516．53MPa，提高了13．7％；合金低温横向抗拉强度与屈服强度分别提高了23．6％和20．0％。低温变形时合金横向、纵向伸长率均稍有提高。这是由于在低温变形过程中平面滑移受抑制，加工硬化指数增加，变形均匀性增强，导致材料的强度增加，塑性提高。

Tensile properties of 2519 aluminum alloy at low temperature

Tensile properties of 2519 aluminum alloy at low temperature were investigated by means of tensile properties test, scanning electron microscopy and transmission electron microscopy. The results show that when temperature is lowered from 293 K to 77 K, the ultimate tensile strength of the specimens in longitudinal direction is drastically increased from 493.64 MPa to 607.35 MPa, while the yield strength is increased from 454.83 MPa to 516.53 MPa. The ultimate tensile strength and yield strength of the specimens in longitudinal direction are increased drastically by 23. 1 % and 13. 7%, while those of the specimens in transverse direction are increased by 23.6% and 20.0%, respectively. And the ductility of those specimens deformed at 77 K is increased a little. Deformed at low temperature, planar slip is inactivated in order that deformation homogeneity and strain hardenability are both strengthened.