Publication detail

Microstructure and mechanical properties of Ni1,5Co1,5CrFeTi0,5 high entropy alloy fabricated by mechanical alloying and spark plasma sintering

MORAVČÍK, I. ČÍŽEK, J. ZAPLETAL, J. KOVACOVA, Z. VESELY, J. MINÁRIK, P. KITZMANTECH, M. NEUBAUER, E. DLOUHÝ, I.

English title

Microstructure and mechanical properties of Ni1,5Co1,5CrFeTi0,5 high entropy alloy fabricated by mechanical alloying and spark plasma sintering

Type

journal article in Web of Science

Language

en

Original abstract

The present work is focused on synthesis and mechanical properties evaluation of non-equiatomic Ni1,5Co1,5CrFeTi0,5, ductile single phase high entropy alloy (HEA) with excellent mechanical properties (bend strength Rmb = 2593 MPa, tensile strength Rm = 1384 MPa, tensile elongation to fracture of 4.01%, and elastic modulus of 216 GPa) surpassing those of traditional as-cast HEA. For the alloy production, a combination of mechanical alloying (MA) process in a planetary ball mill and spark plasma sintering (SPS) for powder densification was utilized. The tensile properties of a bulk material produced by a combination of MA+SPS are characterized for the first time. The feedstock powder and corresponding bulk material microstructure, elemental and phase composition, and mechanical properties were investigated by scanning (SEM) and transmission (TEM) electron microscopy, energy-dispersive X-ray spectroscopy (EDX), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), aswell as impulse excitation of vibration, Vickers microhardness and tensile and bend strength tests, respectively. The structure of the samples consisted of single-phase FCC high entropy solid solution of extremely fine-twinned grains and oxide inclusions inherited from the original powder feedstock. Dimple-like morphology corresponding to ductile fracture mode has been observed on the fracture surfaces, with crack initiation sites on the inclusions phases.

English abstract

The present work is focused on synthesis and mechanical properties evaluation of non-equiatomic Ni1,5Co1,5CrFeTi0,5, ductile single phase high entropy alloy (HEA) with excellent mechanical properties (bend strength Rmb = 2593 MPa, tensile strength Rm = 1384 MPa, tensile elongation to fracture of 4.01%, and elastic modulus of 216 GPa) surpassing those of traditional as-cast HEA. For the alloy production, a combination of mechanical alloying (MA) process in a planetary ball mill and spark plasma sintering (SPS) for powder densification was utilized. The tensile properties of a bulk material produced by a combination of MA+SPS are characterized for the first time. The feedstock powder and corresponding bulk material microstructure, elemental and phase composition, and mechanical properties were investigated by scanning (SEM) and transmission (TEM) electron microscopy, energy-dispersive X-ray spectroscopy (EDX), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), aswell as impulse excitation of vibration, Vickers microhardness and tensile and bend strength tests, respectively. The structure of the samples consisted of single-phase FCC high entropy solid solution of extremely fine-twinned grains and oxide inclusions inherited from the original powder feedstock. Dimple-like morphology corresponding to ductile fracture mode has been observed on the fracture surfaces, with crack initiation sites on the inclusions phases.

Keywords in English

Multi principal element alloy Tensile strength Fracture Ductility

Released

16.01.2017

Publisher

ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND

Location

OXON, ENGLAND

ISSN

1873-4197

Volume

119

Number

1

Pages from–to

141–151

Pages count

10

BIBTEX


@article{BUT135301,
  author="Igor {Moravčík} and Jan {Čížek} and Josef {Zapletal} and Zuzana {Kovacova} and Jozef {Vesely} and Peter {Minárik} and Michael {Kitzmantech} and Erich {Neubauer} and Ivo {Dlouhý},
  title="Microstructure and mechanical properties of Ni1,5Co1,5CrFeTi0,5 high entropy alloy fabricated by mechanical alloying and spark plasma sintering",
  year="2017",
  volume="119",
  number="1",
  month="January",
  pages="141--151",
  publisher="ELSEVIER SCI LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND",
  address="OXON, ENGLAND",
  issn="1873-4197"
}