Creep constitutive model of 7050⁃T7451 aluminum alloy based on damage mechanics

The creep behavior of 7050-T7451 aluminum alloy under different temperatures and stresses was studied by the uniaxial tensile creep test. Based on continuum damage mechanics, a constitutive model describing the creep behavior of aluminum alloy at high temperature was established. The model took into account the precipitation coarsening, dislocation multiplication/annihilation and microvoid formation during the creep process, and introduced the corresponding damage factor evolution formula to reflect these three damage processes. In addition, the model took into account the additional damage caused by stress increase to reveal the effect of stress on the creep damage. Based on the comparative analysis of the test results and the predicted results, it was verified that the established physical constitutive model can accurately describe the creep behavior of 7050 aluminum alloy under different temperatures and stresses.