Disordering of L1₂ Phase in High‐Entropy Alloy Deformed at Cryogenic Temperature

Abstract

Recently, novel high‐entropy alloys (HEAs) of Al–Co–Cr–Fe–Ni–Ti systems containing face‐centered cubic (FCC) matrix and γ′ precipitates (L12 phase) have been studied. They show superior mechanical properties at room (298 K) and cryogenic temperatures (77 K). Herein, microstructure deformation and fracture after tensile strain are investigated. The results show that multiple‐layered stacking faults occur after the tensile test at 77 K, which can increase the yield strength and ultimate tensile strength by 20% and 24%, respectively. The γ′ precipitates become disordered after the alloy deforms at 77 K, which decreases the formation barrier of mechanical twinning and increases ductility at 77 K by 27%.

Strengthening of Fe50Mn25Ni10Cr15 Medium‐Entropy Alloys by Mo Addition for Cryogenic Applications

“…to further improve the cryogenic mechanical properties of these FCC H/MEAs. [ 11–13 ] Unfortunately, these H/MEAs rely on expensive Co element, thus the high raw material cost hinders the large‐scale industrial applications of H/MEAs. [ 6,9,14,15 ] Therefore, numerous efforts are still need to be devoted to exploring cost‐effective H/MEAs.…”