Work

Ultra-Low Temperature Mechanical Response of Laser Powder Bed Fusion–Processed C-Containing CoCrFeMnNi High-Entropy Alloy

Year: 2026

Type: article

Abstract: This study examined the microstructure and tensile behavior, from room temperature to 4.2 K, of a carbon-containing CoCrFeMnNi high-entropy alloy (HEA) fabricated by laser powder bed fusion (LPBF). Microstructural analysis revealed that the LPBF-built HEA comprised a single face-centered cubic (FCC) phase and exhibited epitaxial grain growth along the build direction. Dislocation cell structures and Cr-rich carbides were also observed within the grains. Tensile testing demonstrated a monotonic increase in both yield strength and ultimate tensile strength with decreasing temperature, and the LPBF-fabricated HEA consistently exhibited higher strength than its wrought counterpart across the entire temperature range investigated. Deformation twins were identified in all tested specimens, with the twin fraction increasing markedly at 4.2 K. These findings suggest that the excellent mechanical performance of the LPBF-fabricated carbon-containing CoCrFeMnNi HEA under ultra-low-temperature conditions is attributable to the combined effects of process-inherent microstructural features and pronounced deformation twinning.

Source: Hanguk bunmal jaeryo hakoeji

DOI: 10.4150/jpm.2026.00101

Authors: Jae-Yong Cheon, Seong-June Youn, Young-Sang Na, Young-Kyun Kim

Institution: Korea Institute of Materials Science

Language: English

Topic: High Entropy Alloys Studies

Subfield: Mechanical Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: hybrid

Funders: National Research Foundation of Korea, Korea Institute of Materials Science

Awards: G3696649767, G4609034824