Investigation of anisotropic creep-ageing behaviour of Al-Cu-Li alloy AA2050

Abstract

Creep age forming (CAF) of an Al-Cu-Li alloy (AA2050-T34) considering its anisotropic creep-ageing behaviour has been experimentally and numerically investigated in this study. A series of uniaxial creep-ageing tests of AA2050-T34 has been carried out in both tension and compression conditions. The creep-ageing results in longitudinal and transverse samples show some anisotropic behaviour in both the room temperature yield strength and the creep strain, in which more strengthening occurs at the intermediate stage and less creep strain is produced in the transverse samples than the longitudinal samples under the same loading condition. It is also found that compressive loading results in much higher anisotropic behaviour than tensile loading. A material model has been adopted for the creep-ageing of AA2050 and shows a good fit to experimental data. Based on the model, a four-point bending virtual test has been developed in PAM-STAMP for simulating the CAF process of AA2050. The results indicate that the anisotropic behaviour contributes an apparent effect on both creep-aged properties and springback of the CAF process and need be considered for CAF manufacture of AA2050 components.