Effects of Specimen Thickness and Non-Isothermal Process on Creep Behavior of AA2024 Aluminum Alloy

Abstract

Fiber metal laminate (FML) is a kind of lightweight material that has garnered much attention in recent years due to its excellent properties under tensile, flexure, and impact conditions. However, little attention has been paid to the evolution of aluminum alloy during the FML forming process. In this paper, the effects of specimen thickness and the non-isothermal process on creep behavior of AA2024 aluminum alloy, which is generally used in FMLs, were systematically studied in terms of creep strain, mechanical properties, and microstructure. The results show that the microstructure and mechanical properties of the aluminum alloy layer are greatly affected by the creep age during the FML forming process, but the specimen thickness has little effect on the creep behavior under experimental conditions. During the non-isothermal process, the creep strain generated during the heating stage is about 40% of total strain. Compared with the isothermal process, the creep strain of the non-isothermal process increases by 20–40%, and the apparent activation energy Qc is larger. According to the creep behavior of AA2024 aluminum alloy during the non-isothermal process, a creep constitutive model was established to accurately simulate the deformation of FMLs.

Keywords

• AA2024 aluminum alloy
• thickness effect
• creep age forming
• microstructure
• non-isothermal constitutive modeling