Creep behaviors of highly pure aluminum at lower temperatures

We have carried out experiments on the creep behaviors of pure aluminums at lower temperatures from a phenomenological viewpoint. The creep curves are classified into three regions; the transient, steady-state and terminal ones. The creep curve changes from a logarithmic to a constant strain rate curve at a higher applied stress. The creep curves yield a constant creep rate for a long period though lattice diffusion is less active at 293 K. The creep rate depends upon the applied stress. Cyclic stressing has an effect on the creep life of the materials. Both increasing and decreasing the applied stress reduce the rupture time. Since the steady-state creep is associated with the stable structure, is takes time to shift to the new structure built under the different applied stress. The hysteresis effect does some damage to the creep life of the pure aluminum.