# Phase Diagram of Carbon Nickel Tungsten: Superatom Model

## TL;DR

This study combines first-principles calculations and Monte Carlo simulations to predict the phase diagram and carbon solubility in C-Ni-W alloys, providing insights into alloy behavior at various temperatures.

## Contribution

It introduces a superatom model based on DFT data for efficient phase diagram prediction of C-Ni-W alloys, advancing computational materials science methods.

## Key findings

- Predicted carbon solubility limits at different temperatures.
- Mapped phase diagrams of C-Ni-W alloys.
- Validated superatom model against ideal mixing approximation.

## Abstract

Carbon solubility in face-centered cubic Ni-W alloys and the phase diagram of C-Ni-W are investigated by means of first principle calculations and semi-grand canonical Monte Carlo simulations. With density functional theory (DFT) total energies as fitting data, we build a superatom model for efficient simulation. Multi-histogram analysis is utilized to predict free energies for different compositions and temperatures. By comparing free energies of competing phases, we are able to predict carbon solubility and phase diagrams of C-Ni-W at different temperatures. A simple ideal mixing approximation gives qualitatively similar predictions.