Modeling for Predicting Flow Stress of Al-14Cu-7Ce Alloy at Elevated Temperature

Isothermal hot compression tests of annealed Al-14Cu-7Ce alloy were carried out on Gleeble-3500 system in the temperature range from 573 K to 823 K and the stain rate range from 0.001 s(-1) to 1 s(-1). The resulted true stress-true strain data were employed to establish a constitutive equation for predicting high temperature flow stress. The results show that the flow stress follow well the rate equation (epsilon) over dot = A D(L)Gb/KT [sinh (alpha(L)sigma/G](n). The effect of strain was taken into account by fitting of polynomials into the material parameters A, alpha(L), and n. The proposed constitutive equation can predict precisely high temperature flow stress of Al-14Cu-7Ce alloy. The control mechanism of hot deformation is dislocation climb.