A precipitation-strengthened high-entropy alloy for additive manufacturing

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

8 Scopus Citations
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Author(s)

  • Kexuan Zhou
  • Feng He
  • Junjie Li
  • Jincheng Wang

Detail(s)

Original languageEnglish
Article number101410
Journal / PublicationAdditive Manufacturing
Volume35
Online published25 Jun 2020
Publication statusPublished - Oct 2020

Abstract

As newly developed metallic materials, several high-entropy alloys (HEAs) have been fabricated via additive manufacturing (AM) and have been found to exhibit more uniform microstructures and better mechanical properties than their as-cast counterparts. However, current additive-manufactured HEAs are relatively unsatisfactory in terms of strength owing to the inevitable micropores or microcracks that occur during their processing. A significant challenge is to further increase the mechanical properties of single-solid-solution HEAs for AM. In light of this, in the present study, a precipitation-strengthened Ni2.1CoCrFeNb0.2 HEA was designed that is particularly easy to print for use in AM. Bulk samples without observed defects were successfully produced by direct laser deposition. The as-deposited Ni2.1CoCrFeNb0.2 HEA showed an excellent strength-ductility combination. After proper heat-treatments, the tensile strength increased dramatically to ∼ 1127 MPa with a tensile elongation of ∼ 17 %, which is the best performance in the reported AM-fabricated HEAs. The precipitation of the γ″ phase was quantitatively analyzed to reveal the excellent strengthening effect in this new AM-fabricated HEA. In the present study, a superior precipitation-reinforced HEA with fully dense microstructures was successfully developed for AM. These results open up new possibilities for the further development of AM-fabricated HEAs.

Research Area(s)

  • Additive manufacturing, Coherent nanoparticles, High-entropy alloy, Mechanical properties, Precipitation hardening