Influence Of Partial Substitution Of Cr By Al On Microstructure And Mechanical Behavior Of Fe30Ni35Cr35 Multi-principal Element Alloy

Abstract

Influence of partial substitution of Cr by Al on microstructure and mechanical behavior of Fe30Ni35Cr35 multi-principal element alloy (MPEA) was investigated. In detail, Co-free Fe30Ni35Cr(35-x)Alx (x = 10, 12.5, 13.75 and 15 at.%) MPEAs were prepared by a vacuum arc melting process, subsequently, microstructure and tensile properties of these MPEAs were carefully studied. The as-cast Fe30Ni35Cr(35-x)Alx alloys are composed of face-centered cubic (FCC) and body-centered cubic (BCC) phases with spherical B2 nano-precipitates embedded in the BCC phase and B2 lamellar structure surrounding the BCC phase simultaneously. In particular, Al content strongly influences the solidification process of these alloys; with increasing Al content, the initial morphology varied from columnar dendritic grains (10 < x < 13.75) to equiaxed grains with Widmanstätten structures (x = 15) and resulted in increased tensile strength and hardness with reduced ductility. The as-cast Fe30Ni35Cr21.25Al13.75 alloy exhibits the best mechanical properties in Fe30Ni35Cr(35-x)Alx alloys with an ultimate tensile strength (UTS) of ∼1111.8 ± 11.4 MPa and a total elongation of ∼20.7 ± 2.1%. Furthermore, our study demonstrates outstanding combinations of ductility and strength in multi-phase MPEAs, ascribing to various complementary strengthening mechanisms, such as hetero-deformation induced (HDI) hardening and precipitation strengthening, which influence the work hardening and dislocation movement at different tensile strains.

Department(s)

Materials Science and Engineering

Comments

National Natural Science Foundation of China, Grant 52103360

Keywords and Phrases

Deformation mechanism; Hetero-deformation induced hardening; Multi-principal element alloys; Precipitation strengthening; Tensile properties

International Standard Serial Number (ISSN)

0042-207X

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2023 Elsevier, All rights reserved.

Publication Date

01 Sep 2023

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