Micromechanical viscoplastic stress-strain model with grain boundary sliding. Final report

摘要

This project was initiated to develop and experimentally verify a self-consistent micromechanics model of polycrystalline Hastelloy-X. A viscoplastic constitutive model was developed for the estimation of the overall mechanical behavior of Hastelloy-X polycrystalline metal from a knowledge of the single crystal behavior. The deformation behavior of the polycrystal was derived from that of single crystals by using a self-consistent method. The single crystal behavior was developed by summing postulated slip on crystallographic slip systems. Plasticity and creep were modeled using a unified viscoplastic model which includes the interaction between these phenomena at elevated temperatures. The validity of the model was directly tested by critical experiments on Hastelloy-X in both the single crystal and polycrystalline versions.