Deformation Mechanisms Coupled with Phase Field and Crystal Plasticity Modeling in a High-temperature Polycrystalline Ni-based Superalloy

Abstract

Physics-based modeling of disk superalloys is inherently complex due to the strong influence of microstructure on properties, as well as the multitude of deformation mechanisms operative at elevated temperatures. The present contribution will focus on the effects of monotonic and cyclic loading conditions, and the underlying deformation mechanisms will be discussed. Detailed substructure analysis of deformed specimens was conducted with scanning transmission electron microscopy diffraction-contrast methods. These characterization efforts have led to a series of phase field simulations in which the interaction of various deformation modes with experimentally measured precipitate configurations can be explored and critical parameters quantified. Additionally, these results have been incorporated into a novel, dislocation-densitybased crystal plasticity model that has been calibrated based on a single crystal response, and enables the computationally efficient modeling of polycrystalline behavior.

Gas Bubble Evolution in Polycrystalline UMo Fuels Under Elastic-Plastic Deformation: A Phase-Field Model With Crystal-Plasticity

“…In the absence of irradiation damage, a number of microstructure-dependent plastic and creep deformation models have been developed (Deutchman et al, 2012;Cottura et al, 2016;Wu and Sandfeld, 2017;Yang et al, 2018). A homogenized crystal plasticity FEM Model (Deutchman et al, 2012), which uses crystal plasticity parameters (such as activation energy, passing stress and activation volume) provided by a dislocation-density based crystal plasticity modeling, was developed to study the effect of various microstructures (precipitate shape and volume fraction, and channel width) on plastic deformation in Ni based superalloys. An empirical constitutive model-based phase-field model (Tsukada et al, 2011), which uses the von Mises yield criterion for plastic deformation and a simple creep evolution equation, was developed to study the evolution of microstructure and inelastic (plastic and creep) deformation during high temperature creep in nickel-based superalloys.…”