Phase transitions of eutectic high entropy alloy AlCoCrFeNi2.1 under shock compression

TL;DR

This study investigates the phase transitions of eutectic high entropy alloy AlCoCrFeNi2.1 under shock compression up to 400 GPa using experiments and simulations, revealing phase stability and structural evolution insights.

Contribution

It provides new experimental and simulation data on the structural evolution of AM-EHEA AlCoCrFeNi2.1 under extreme pressures, enhancing understanding of its phase stability.

Findings

Detection of fcc and bcc phases at various pressures

Identification of pure- and mixed-phase regions

Insights into phase stability under high pressure

Abstract

High entropy alloys (HEAs) are a new class of metals that exhibit unique mechanical performance. Among HEAs, additively manufactured eutectic high entropy alloys (AM-EHEAs) have recently emerged as candidate materials for use in extreme conditions due to their simultaneous high strength and ductility. However, the deformation and structural evolution of AM-EHEAs under conditions of high pressure have not been well characterized, limiting their use in extreme applications. We present dynamic compression experiments and molecular dynamics simulations studying the structural evolution of AM-EHEA AlCoCrFeNi2.1 when compressed to pressures up to 400 GPa. Our in-situ X-ray diffraction measurements capture the appearance of fcc and bcc phases at different pressure conditions, with pure- and mixed-phase regions. Understanding the phase stability and structural evolution of the AM EHEA offers new insights to guide the development of high-performance complex materials for extreme conditions.