Enhancing fatigue life by ductile-transformable multicomponent B2 precipitates in a high-entropy alloy

• Published in: Nature communications Vol. 12; no. 1; p. 3588
• Main Authors: Feng, Rui, Rao, You, Liu, Chuhao, Xie, Xie, Yu, Dunji, Chen, Yan, Ghazisaeidi, Maryam, Ungar, Tamas, Wang, Huamiao, An, Ke, Liaw, Peter. K.
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 11.06.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 147/135; 147/143; 639/301/1023/1026; 639/301/1023/303; Alloys; Catastrophic failure analysis; Chemical precipitation; Crack initiation; Crack propagation; Deformability; Deformation; Deformation mechanisms; Electron microscopy; Entropy; Failure mechanisms; Fatigue failure; Fatigue life; Formability; High entropy alloys; Humanities and Social Sciences; Intermetallic phases; Martensitic transformations; MATERIALS SCIENCE; mechanical properties; Metal fatigue; metals and alloys; Monte Carlo simulation; multidisciplinary; Neutron diffraction; Phase transitions; Plasticity; Precipitates; Precipitation hardening; Science; Science (multidisciplinary); Strengthening; Twinning
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-021-23689-6

Catastrophic accidents caused by fatigue failures often occur in engineering structures. Thus, a fundamental understanding of cyclic-deformation and fatigue-failure mechanisms is critical for the development of fatigue-resistant structural materials. Here we report a high-entropy alloy with enhanced fatigue life by ductile-transformable multicomponent B2 precipitates. Its cyclic-deformation mechanisms are revealed by real-time in-situ neutron diffraction, transmission-electron microscopy, crystal-plasticity modeling, and Monte-Carlo simulations. Multiple cyclic-deformation mechanisms, including dislocation slips, precipitation strengthening, deformation twinning, and reversible martensitic phase transformation, are observed in the studied high-entropy alloy. Its improved fatigue performance at low strain amplitudes, i.e., the high fatigue-crack-initiation resistance, is attributed to the high elasticity, plastic deformability, and martensitic transformation of the B2-strengthening phase. This study shows that fatigue-resistant alloys can be developed by incorporating strengthening ductile-transformable multicomponent intermetallic phases. A fundamental understanding of fatigue-failure mechanisms is key to develop robust structural materials. Here the authors report a high entropy alloy with enhanced fatigue life by ductile transformable multicomponent B2 precipitates, as revealed by combined experimental and simulation methods.