Ultrastrong duplex high-entropy alloy with 2 GPa cryogenic strength enabled by an accelerated martensitic transformation. (October 2019)

• Record Type: Journal Article
• Authors: Kim, Dong Geun; Jo, Yong Hee; Yang, Junha; Choi, Won-Mi; Kim, Hyoung Seop; Lee, Byeong-Joo; Sohn, Seok Su; Lee, Sunghak
• Is Part Of: Scripta materialia. Number 171(2019)
• Page Start: 67
• Page End: 72
• Publication Date: 2019-10
• Subjects: High-entropy alloy -- Phase stability -- Transformation induced plasticity -- Strain hardening -- Cryogenic strength; Materials -- Periodicals; Metallurgy -- Periodicals; Metalen; Legeringen; Materiaalkunde; Metals, metalworking and machinery industries; Metals; Electronic journals; 620.11
• DOI: 10.1016/j.scriptamat.2019.06.026
• Languages: English
• ISSNs: 1359-6462

Abstract

Abstract: The existing deformation-induced martensitic transformation mostly focuses on overcoming the trade-off of cryogenic strength-ductility; however, an enhancement of cryogenic strength further is still challenging. We present a concept to yield a cryogenic strength of 2 GPa in a duplex V10 Cr10 Co30 Fe50 alloy. We adopt a thermodynamic calculation to reduce the stability of metastable face-centered-cubic (FCC) matrix, significantly promoting the martensitic transformation. In conjunction with the chemically driven promotion, the duplex structure including athermal body-centered-cubic (BCC) martensite enables mechanical strain partitioning to accelerate the transformation further. This finding could be an appropriate design strategy to develop new ultrastrong alloys for cryogenic applications. Graphical abstract: Unlabelled Image