Phase Transitions of Eutectic High Entropy Alloy AlCoCrFeNi _2.1 Under Shock Compression

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. Dynamic compression experiments and molecular dynamics simulations are presented to study the structural evolution of AM EHEA AlCoCrFeNi 2.1 when compressed to pressures up to 400 GPa. In situ X‐ray diffraction measurements capture the appearance of face‐centered cubic and body‐centered cubic 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.