Ultrahigh-strength and ductile CoCrFeNi-based high-entropy alloys manufactured by laser powder bed fusion with multiple strengthening mechanisms

Wu，Zhining1; He，Minglin2; Cao，Hailin2; Wang，Shanshan1; Chen，Ruiguang1; Cao，Boxuan1; Shi，Rongpei1; Liu，Xingjun1; Yu，Suzhu1; Wang，Shuai2; Bai，Jiaming2; Wei，Jun1

2023-07-01

10.1016/j.jmrt.2023.06.110

Journal of Materials Research and Technology   Impact Factor & Quartile

2238-7854

2214-0697

Laser powder bed fusion (L-PBF) has been proposed as a potential manufacturing process of high-entropy alloys involving rapid cooling rate and compositional element tuning. It, to some extent, compensates for the lack of strength of face-centered cubic (FCC) CoCrFeNi alloy by introducing high-density dislocations and generating hierarchical structures. In this study, the CoCrFeNi-based alloy was manufactured by L-PBF with the minor addition of BC micro-particles and their properties and microstructure were evaluated. Nano-sized precipitates consisting of the boride and varying carbides were found in the form of a core-shell structure. An in-site transformation of carbides appeared around the core of the precipitate due to a large temperature gradient in the melt pool during manufacturing. The tensile yield and ultimate strength of CoCrFeNi–BC alloy (1249.5 MPa and 1421.0 MPa) are double that of CoCrFeNi matrix (624.5 MPa and 691.1 MPa) at room temperature with competitive ductility. The exceptional mechanical properties can be mainly ascribed to precipitate hardening, dislocation hardening and grain refinement, as well as the particle-dislocation interaction.

CoCrFeNi-based high-entropy alloy Laser powder bed fusion Nano-size precipitates Strengthening mechanism Tensile properties

SCI

English

Corresponding

National Natural Science Foundation of China[52201257];

Materials Science ; Metallurgy & Metallurgical Engineering

Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:001092001500001

ELSEVIER

2-s2.0-85163565615

Scopus

1.School of Materials Science and Engineering,Harbin Institute of Technology (Shenzhen),Shenzhen,518055,China
2.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,1088 Xueyuan Avenue,518055,China

Wu，Zhining,He，Minglin,Cao，Hailin,et al. Ultrahigh-strength and ductile CoCrFeNi-based high-entropy alloys manufactured by laser powder bed fusion with multiple strengthening mechanisms[J]. Journal of Materials Research and Technology,2023,25:2948-2960.

Wu，Zhining.,He，Minglin.,Cao，Hailin.,Wang，Shanshan.,Chen，Ruiguang.,...&Wei，Jun.(2023).Ultrahigh-strength and ductile CoCrFeNi-based high-entropy alloys manufactured by laser powder bed fusion with multiple strengthening mechanisms.Journal of Materials Research and Technology,25,2948-2960.

Wu，Zhining,et al."Ultrahigh-strength and ductile CoCrFeNi-based high-entropy alloys manufactured by laser powder bed fusion with multiple strengthening mechanisms".Journal of Materials Research and Technology 25(2023):2948-2960.