High Temperature Inelastic Deformation Under Uniaxial Loading: Theory and Experiment

Abstract

The elevated temperature, uniaxial inelastic deformation behavior of a Ni-base alloy, B1900 + Hf, has been investigated by performing isothermal tensile, creep, cyclic, stress relaxation, and thermomechanical fatigue tests. The range of strain rates examined are 10−7 to 10−2 s−1 , while the test temperatures range from 25°C to 1093°C. This extensive constitutive data base has been used for evaluating the unified constitutive models of Bodner-Partom and of Walker which apply for the small strain regime. Comparison of test results with independent model predictions indicates good agreement over a broad range of loading conditions demonstrating the applicability of the unified constitutive equation approach for describing the strongly nonlinear, time, and temperature-dependent response of metals under a wide range of deformation and thermal histories. Thus, the results give confidence that the unified approach is an effective and efficient approach in which complex, history-dependent, thermo-viscoplastic flow can be represented within a single inelastic strain-rate term.