PHYSICALLY CONSISTENT METHOD FOR THE PREDICTION OF CREEP BEHAVIOR OF METALS.

A physically consistent method, which considers the deformation mechanisms, the active and latent hardening in single crystals, and their transient and steady creep, is proposed to predict the creep behavior of polycrystalline materials. This method consists of two steps: first, the material constants of single crystals are determined from the tensile creep data of the polycrystal, and then these constants are used to predict the creep properties of the same polycrystal under required loading conditions. This method simultaneously satisfies the requirements of equilibrium and compatibility over the grain boundaries, and is self-consistent. The proposed method was applied to calculate the creep strains of a 2618-T61 Aluminum alloy under pure shear, combined stress and nonradial loading; the results obtained were in good agreement with the test data.