Journal of Alloys and Compounds2022，Vol.91512.DOI:10.1016/j.jallcom.2022.165400

Hierarchical eutectic structure and superior mechanical property in low cobalt content AlCo0.2CrFeNi2.1 alloy by laser metal deposition

Feng, Chong Liu, Xiaochun Wang, Jiang Chai, Xiaoyu Sun, Zhonggang Tao, Xiaoma Chen, Fuwen Xu, Guanglong Cui, Yuwen
Journal of Alloys and Compounds2022，Vol.91512.DOI:10.1016/j.jallcom.2022.165400
✕
  • NSTL
  • Elsevier

Hierarchical eutectic structure and superior mechanical property in low cobalt content AlCo0.2CrFeNi2.1 alloy by laser metal deposition

Feng, Chong 1Liu, Xiaochun 2Wang, Jiang 3Chai, Xiaoyu 1Sun, Zhonggang 1Tao, Xiaoma 4Chen, Fuwen 1Xu, Guanglong 1Cui, Yuwen1
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作者信息

  • 1. Nanjing Tech Univ
  • 2. Changsha Univ Sci & Technol
  • 3. Guilin Univ Elect Technol
  • 4. Guangxi Univ
  • 折叠

Abstract

The fabrication of AlCo0.2CrFeNi2.1 high entropy alloy via laser metal deposition (LMD) was motivated and implemented by the demand for overcoming the strength-ductility trade-off of the as-cast alloys due to the Co concentration. The microstructure features of AlCo0.2CrFeNi2.1 alloy were characterized by scanning electron microscopy, X-ray diffraction, transmission electron microscopy, and electron back-scattered diffraction. The mechanical properties were evaluated by a tensile test at room temperature. The synergy of reduced Co content and LMD process led to the formation of hierarchical eutectic microstructures consisting of columnar grains, eutectic colonies, alternately arranged fcc(L12)+B2 lamellae, and coherent Cr-rich nanoprecipitates in B2. The growth direction of those eutectic structures was found to be mainly parallel to the building direction (BD). The fcc(L12)/B2 eutectics agreed well with the Kurdjumov-Sachs orientation relationship of [110}B2//[111}L12, and < 111 > B2// < 110 > L12. The LMD fabricated AlCo0.2CrFeNi2.1 exhibited anisotropic mechanical properties when stretched in BD and transverse direction (TD). An excellent combination of the ultimate tensile strength (1246 MPa) and ductility (17.1%) was achieved in the BD, better than the as-cast counterpart. The elevated mechanical properties could be attributed to the high cooling rate solidification induced microstructural refinement. The same interlamellar spacing in BD and TD embraced a nearly equal ability to block dislocation movement and gave rise to the similar yield tensile strength. The differences in grain/colony size induced boundary strengthening in BD and TD were evaluated to account for the remarkable changes in ultimate tensile strength as well as ductility. (c) 2022 Elsevier B.V. All rights reserved.

Key words

Laser metal deposition (LMD)/AlCo 0/2 CrFeNi 2/1/Microstructure features/Tensile property/Strengthening/HIGH-ENTROPY ALLOY/STRENGTHENING MECHANISMS/MICROSTRUCTURE EVOLUTION/DUCTILITY/PLASTICITY/DEFORMATION/BEHAVIOR/DESIGN

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出版年

2022
Journal of Alloys and Compounds

Journal of Alloys and Compounds

EISCI
ISSN：0925-8388
被引量5
参考文献量106
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