Nano-graining a particle-strengthened high-entropy alloy

• Main Authors: Lee, Dong-Hyun, Park, Jeong-Min, Yang, Guanghui, He, Junyang, Lu, Zhaoping, Suh, Jin-Yoo, Kawasaki, Megumi, Ramamurty, Upadrasta, Jang, Jae-il
• Other Authors: School of Mechanical and Aerospace Engineering
• Format: Article
• Language: English
• Published: 2021
• Subjects: Engineering::Mechanical engineering; High-entropy Alloy; Particle Strengthening
• Online Access: https://hdl.handle.net/10356/151737
• Institution: Nanyang Technological University

The possibility of further enhancing the strength of a (CoCrFeNi)₉₄Ti₂Al₄ high-entropy alloy (HEA), which is already strengthened by Ni₃(Ti,Al) second-phase particles, by grain refinement through high-pressure torsion (HPT) is examined. Concomitant with nanograin formation, HPT was found to induce particle dissolution and structural transformation of the remnant particles. Nanoindentation experiments of nanocrystalline HEA, with and without particles in the pre-HPT microstructure, suggests that grain boundary strengthening is the dominant strengthening mechanism.