Tailoring Microstructure And Tensile Properties Of Low-cost AlCrFeNi-based High-entropy Alloys Via Co And/or Ti Addition

Abstract

Al-Cr-Fe-Ni high-entropy alloys (HEAs) have low cost but suffer from intrinsic brittleness, leading existing research to concentrate on compressive properties. This study explores alloying strategies to improve tensile properties for these HEAs. Minor elements including 5 at.% Co, 5 at.% Co + 3 at.% Ti, and 5 at.% Co + 5 at.% Ti are added to investigate their impact on microstructure, tensile properties, and solidification behavior for Fe30Ni35Cr21.25Al13.75 HEA. The addition of both Co and Ti has a synergistic effect on the alloys; however, it does not alter the types of phases present, as the face-centered cubic (FCC), body-centered cubic (BCC), and B2 phases are maintained. Specifically, the increase of Ti content promotes the transformation of the primary phase from FCC to BCC and causes the BCC phase to undergo spinodal decomposition. The addition of Co alone decreases the strength, whereas the synergistic combination of Co and Ti enhances the yield strength (from ∼571 MPa to ∼625 MPa) and ultimate tensile strength (from ∼1112 MPa to ∼1288 MPa). Nonetheless, the total elongation is only reduced by 1.5% with this combination. Specially, introducing 5% Ti into the alloy instantly renders it brittle. These results provide valuable insights into improving the mechanical properties and understanding the solidification behavior of low-cost Al-Cr-Fe-Ni HEAs through synergistic alloying.

Department(s)

Materials Science and Engineering

Comments

National Natural Science Foundation of China, Grant 2021QN02C766

Keywords and Phrases

High-entropy alloys; Solidification behavior; Tensile properties; Thermodynamic calculation

International Standard Serial Number (ISSN)

1044-5803

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

01 Dec 2023

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