Enhanced strength and ductility of laser powder bed fused NbMoTaW refractory high-entropy alloy via carbon microalloying

Jintao Xu; Ran Duan; Kai Feng; Chengcheng Zhang; Qingjun Zhou; Pan Liu; Zhuguo Li

Additive Manufacturing Letters (Dec 2022)

Enhanced strength and ductility of laser powder bed fused NbMoTaW refractory high-entropy alloy via carbon microalloying

Jintao Xu,
Ran Duan,
Kai Feng,
Chengcheng Zhang,
Qingjun Zhou,
Pan Liu,
Zhuguo Li

Affiliations

Jintao Xu: Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
Ran Duan: Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
Kai Feng: Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai, 200240, China; Corresponding authors.
Chengcheng Zhang: Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China
Qingjun Zhou: Capital Aerospace Machinery Corporation Limited, Beijing, 100076, China
Pan Liu: State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
Zhuguo Li: Shanghai Key Laboratory of Materials Laser Processing and Modification, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China; Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration, Shanghai, 200240, China; Corresponding authors.

Journal volume & issue: Vol. 3
p. 100079

Abstract

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NbMoTaW refractory high-entropy alloy (RHEA) shows outstanding mechanical properties at ultra-high temperatures, while room-temperature brittleness limits its application. In this study, carbon (C) microalloying was employed to improve the room-temperature brittleness resistance of NbMoTaW RHEA fabricated using laser powder bed fusion (LPBF). The addition of 0.5-at% C leads to good formability and remarkable microalloying effects. Nano-NbC precipitates distributed at grain boundaries and dislocations effectively refined the grain size. The yield strength, ultimate compression strength, and ductility were successfully improved up to 1725 MPa, 1782 MPa, and 7.0%, respectively. Nano-NbC carbide precipitates in the form of diffusion transformation during multiple reheating was verified by thermodynamics, kinetics calculations, and microstructure characterization. C microalloying endowed NbMoTaW RHEA with remarkable enhancements of strength and ductility, which suggested a strategy for designing strong and ductile RHEA through LPBF.

Published in Additive Manufacturing Letters

ISSN: 2772-3690 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Technology (General): Industrial engineering. Management engineering
Website: https://www.journals.elsevier.com/additive-manufacturing-letters/

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