Exploring the impact of cooling rates and pressure on fragility and structural transformations in iron monatomic metallic glasses: Insights from molecular dynamics simulations

Abstract

In this study, we investigate Fe metallic glass under pressures from 0 to 20 GPa and cooling rates of 5 × 1012 to 1014 K/s using molecular dynamics (MD) simulations with an embedded-atom potential (EAM). Increasing pressure enhances brittleness, indicating a higher barrier energy for the glass transition. Higher pressures narrow the glass transition region, resulting in a shorter relaxation range. At pressures above 10 GPa, especially with a cooling rate of 5 × 1012 K/s, crystal nucleation is promoted, and short-range order strengthens, primarily body-centered cubic structure (bcc) clusters. Certain pressure-cooling rate combinations show significant increments. Pressure affects density and interatomic distance, while cooling rate changes have minimal effects.