Insights from a minimal model of dislocation-assisted rafting in single crystal Nickel-based superalloys

TL;DR

This paper presents a minimal 2D coupled phase-field and dislocation dynamics model that explains early-stage rafting in single crystal Nickel-based superalloys, revealing microstructural interactions without phenomenological parameters.

Contribution

It introduces a novel, parameter-free model that captures the microstructural evolution during creep in superalloys, advancing understanding of dislocation-precipitate interactions.

Findings

Reveals microstructural mechanisms during early rafting

Shows interaction between phases and dislocations

Predicts realistic creep behavior without fitting parameters

Abstract

Nickel-based superalloys play a major role in many technologically relevant high temperature applications. Understanding and predicting the evolution of the phase microstructure during high temperature creep together with the evolution of the dislocation microstructure is a challenge that up to date has not yet been fully accomplished. Our two-dimensional coupled phase-field/continuum dislocation dynamics model explains microstructural mechanisms which are important during the early stage of rafting in a single crystal system. It shows how $\gamma/\gamma'$ phases and dislocations interact giving rise to realistic creep behavior; no phenomenological fit parameters are required.