断续时效对2519A铝合金组织和力学性能的影响

Effects of interrupted ageing on microstructure and mechanical properties of 2519A aluminum alloy

通过硬度试验、拉伸试验、扫描电镜以及透射电镜研究断续时效对2519A铝合金板材微观组织和力学性能的影响。研究表明:2519A铝合金经断续时效(T9I6)后,其屈服强度、抗拉强度和伸长率分别为501 MPa、540 MPa和14%,相比于2519A-T87状态铝合金的450 MPa、480 MPa和9%,分别提高了51 MPa、60 MPa和5%。在断续时效过程中,低温保温可以使基体内不断形成大量临界尺寸的密集、细小的GP区,而使时效相也趋于细小、密集,从而提高了合金的力学性能。

The effect of interrupted ageing on the microstructure and mechanical properties of 2519A aluminum alloy was studied by means of hardness, tensile test, SEM and TEM. After the T9I6 heat treatment, the yield strength, tensile strength and elongation of 2519A aluminum alloy can reach 501 MPa, 540 MPa and 14%, respectively. Compared to T87 temper, which is 450 MPa, 480 MPa and 9%, respectively, the mechanical properties of 2519A-T9I6 increases by 51 MPa, 60 MPa and 5%, respectively. During the process of interrupted aging, keeping the alloy in a lower temperature contributes to forming the numerous, finer and denser GP zone with critical size. So, the following precipitated phase will also be finer and denser, which results in the increasing mechanical properties of 2519A aluminum alloy.