# Artificial Neural Network Approach for Hardness Prediction in High-Entropy Alloys

## TL;DR

This paper uses an artificial neural network to predict the hardness of high-entropy alloys based on their composition, achieving high accuracy and identifying key elements that influence hardness.

## Contribution

The novel contribution is the development of an accurate ANN model with a user-friendly interface for hardness prediction in HEAs.

## Key findings

- The ANN model achieved 99.84% and 99.3% correlation coefficients for training and testing datasets.
- Al, Cr, and Mn increase hardness by stabilizing hard phases like BCC and B2.
- W increases hardness through lattice distortion and intermetallic compound formation.

## Abstract

High-entropy alloys (HEAs) are highly concentrated, multicomponent alloys that have received significant attention due to their superior properties compared to conventional alloys. The mechanical properties and hardness are interrelated, and it is widely known that the hardness of HEAs depends on the principal alloying elements and their composition. Therefore, the desired hardness prediction to develop new HEAs is more interesting. However, the relationship of these compositions with the HEA hardness is very complex and nonlinear. In this study, we develop an artificial neural network (ANN) model using experimental data sets (535). The compositional elements—Al, Co, Cr, Cu, Mn, Ni, Fe, W, Mo, and Ti—are considered input parameters, and hardness is considered as an output parameter. The developed model shows excellent correlation coefficients (Adj R2) of 99.84% and 99.3% for training and testing data sets, respectively. We developed a user-friendly graphical interface for the model. The developed model was used to understand the effect of alloying elements on hardness. It was identified that the Al, Cr, and Mn were found to significantly enhance hardness by promoting the formation and stabilization of BCC and B2 phases, which are inherently harder due to limited active slip systems. In contrast, elements such as Co, Cu, Fe, and Ni led to a reduction in hardness, primarily due to their role in stabilizing the ductile FCC phase. The addition of W markedly increased the hardness by inducing severe lattice distortion and promoting the formation of hard intermetallic compounds.