Physics-Based Machine-Learning Approach for Modeling the Temperature-Dependent Yield Strengths of Medium- or High-Entropy Alloys

TL;DR

This paper introduces a physics-based bilinear log model for predicting the temperature-dependent yield strength of medium- and high-entropy alloys, aiding high-temperature alloy design and reliability assessment.

Contribution

The paper presents a physics-informed bilinear log model with a break temperature for accurate YS prediction across temperature regimes, improving upon black-box machine learning approaches.

Findings

The model accurately predicts YS and ultimate strength across various HEA compositions.

The break temperature Tbreak is consistent for YS and ultimate strength.

Refractory HEAs exhibit superior strength compared to nickel-based superalloys.

Abstract

Machine learning is becoming a powerful tool to predict temperature-dependent yield strengths (YS) of structural materials, particularly for multi-principal-element systems. However, successful machine-learning predictions depend on the use of reasonable machine-learning models. Here, we present a comprehensive and up-to-date overview of a bilinear log model for predicting temperature-dependent YS of medium-entropy or high-entropy alloys (MEAs or HEAs). In this model, a break temperature, Tbreak, is introduced, which can guide the design of MEAs or HEAs with attractive high-temperature properties. Unlike assuming black-box structures, our model is based on the underlying physics, incorporated in form of a priori information. A technique of global optimization is employed to enable the concurrent optimization of model parameters over low- and high-temperature regimes, showing that the break temperature is consistent across YS and ultimate strength for a variety of HEA compositions. A high-level comparison between YS of MEAs/HEAs and those of nickel-based superalloys reveal superior strength properties of selected refractory HEAs. For reliable operations, the temperature of a structural component, such as a turbine blade, made from refractory alloys may need to stay below Tbreak. Once above Tbreak, phase transformations may start taking place, and the alloy may begin losing structural integrity.