Effect of cooling rate on microstructure and mechanical properties of AlCrFe2Ni2 medium entropy alloy fabricated by laser powder bed fusion

Tianyi Han; Jiaying Chen; Zongfan Wei; Nan Qu; Yong Liu; Danni Yang; Sicong Zhao; Zhonghong Lai; Meng Jiang; Jingchuan Zhu

Journal of Materials Research and Technology (Jul 2023)

Effect of cooling rate on microstructure and mechanical properties of AlCrFe2Ni2 medium entropy alloy fabricated by laser powder bed fusion

Tianyi Han,
Jiaying Chen,
Zongfan Wei,
Nan Qu,
Yong Liu,
Danni Yang,
Sicong Zhao,
Zhonghong Lai,
Meng Jiang,
Jingchuan Zhu

Affiliations

Tianyi Han: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
Jiaying Chen: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
Zongfan Wei: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
Nan Qu: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
Yong Liu: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China
Danni Yang: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China
Sicong Zhao: School of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China
Zhonghong Lai: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; Center of Analysis, Measurement and Computing, Harbin Institute of Technology, Harbin 150001, China
Meng Jiang: State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001, China; Corresponding author.
Jingchuan Zhu: School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China; National Key Laboratory for Precision Hot Processing of Metals, Harbin Institute of Technology, Harbin 150001, China; Corresponding author.

Journal volume & issue: Vol. 25
pp. 4063 – 4073

Abstract

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The mechanical properties and serviceability of the alloy fabricated by laser powder bed fusion (L-PBF) additive manufacturing (AM) strongly depend on the phase composition and microstructure, which are affected by the thermal condition of the process, such us cooling rate. In this study, AlCrFe2Ni2 medium entropy alloy (MEA) was fabricated by L-PBF under varying cooling rate via changing process parameters. The phase transformation, microstructure and mechanical properties were experimentally investigated using X-ray diffraction (XRD), scanning transmission electron microscopy (TEM), scanning electron microscope (SEM) and electron backscatter diffraction (EBSD). The cooling rate was numerically calculated using a well-tested multi-physic thermal fluid model. The results showed that cooling rate had a significant effect on phase composition, microstructure and mechanical properties. The as-built MEA with lower cooling rate showed a nano-size structure composed of BCC and ordered B2 phases and a higher yield strength of 2055 MPa. While for the higher cooling rate, the as-built MEA showed a homogeneous structure consisted of single ordered B2 phase and a lower yield strength of 1544 MPa. The threshold value of cooling rate for phase transformation was between 4.9 × 106 K/s and 6.0 × 106 K/s. Through the strengthening mechanism analysis, it was crucial to achieve the nano-size dual-phase microstructure by manipulating cooling for obtaininng desirable mechanical properties in L-PBF AMed AlCrFe2Ni2 MEA.

Published in Journal of Materials Research and Technology

ISSN: 2238-7854 (Print); 2214-0697 (Online)
Publisher: Elsevier
Country of publisher: Netherlands
LCC subjects: Technology: Mining engineering. Metallurgy
Website: https://www.journals.elsevier.com/journal-of-materials-research-and-technology/

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