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Effect of Al content on oxidation behavior of AlxCoCrFeNi (x=0,0.3,0.6,1mole) arc-melted high entropy alloys

Bhattacharya, Rahul LU ; Murty, B.S. ; Fabijanic, Daniel and Hodgson, Peter (2016) National Metallurgist Day, Annual Technical Meeting 2016
Abstract
One of the most anticipated properties of high entropy alloys (HEA) is excellent oxidation resistance. AlxCoCrFeNi (x=0,0.3,0.6,1 mole) HEAs were synthesized by arc melting route, followed by 4 remelting operations to ensure compositional homogenization. Alloys with x = 0 and 0.3 show single phase FCC structure and x = 1 have intricate BCC+B2 structure, whereas x = 0.6 have dual phases – FCC and BCC. Subjected to oxidation in air at 1000°C and 1150°C for 24 hours, CoCrFeNi (x = 0) developed a continuous Cr2O3 layer, while for Al0.3CoCrFeNi, aCr2O3 surface layer and internal Al2O3 was observed. Under the same test conditions, AlCoCrFeNi exhibited a continuous protective Al2O3 surface layer. Al0.6CoCrFeNi having dual phase structure develops... (More)
One of the most anticipated properties of high entropy alloys (HEA) is excellent oxidation resistance. AlxCoCrFeNi (x=0,0.3,0.6,1 mole) HEAs were synthesized by arc melting route, followed by 4 remelting operations to ensure compositional homogenization. Alloys with x = 0 and 0.3 show single phase FCC structure and x = 1 have intricate BCC+B2 structure, whereas x = 0.6 have dual phases – FCC and BCC. Subjected to oxidation in air at 1000°C and 1150°C for 24 hours, CoCrFeNi (x = 0) developed a continuous Cr2O3 layer, while for Al0.3CoCrFeNi, aCr2O3 surface layer and internal Al2O3 was observed. Under the same test conditions, AlCoCrFeNi exhibited a continuous protective Al2O3 surface layer. Al0.6CoCrFeNi having dual phase structure develops Cr2O3 surface and internal Al2O3 over FCC dendritic regions and single Al2O3 surface oxide layer over the BCC interdendritic region. Oxidation resistance increases with increase in Al content. AlCoCrFeNi shows the best oxidation resistance, with a 5 micron thick, adherent, continuous and protective Al2O3 surface layer even at 0.89T m (1150°C) when exposed for
24h. The oxidation resistance of Al0.6CoCrFeNi and AlCoCrFeNi synthesized by arc
melting is far superior to that of Inconel 718 and Inconel 600 superalloys, in terms of oxide layer thickness, adherence, stability and protective behavior. This is due to their higher Al content, which remains dissolved in the alloy phases, owing to configurational entropy stabilization. (Less)
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author
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publishing date
type
Contribution to conference
publication status
published
subject
keywords
High entropy alloys, oxidation behaviour, Mechanical alloying, Spark plasma sintering, High resolution transmission electron microscopy, Scanning electron microscope (SEM), X ray diffraction, EDS, EBSD, Scanning Transmission Electron Microscopy, GDOES, Powder metallurgy (PM), Physical Metallugy, Thermodynamics and kinetics, Sintering, Microstructural evolution, Mechanical properties, Annealing, Heat treatment, Casting, Furnace control, CALPHAD
pages
1 pages
conference name
National Metallurgist Day, Annual Technical Meeting 2016
conference location
Kanpur, India
conference dates
2016-11-11 - 2016-11-14
language
English
LU publication?
no
id
68a1dc37-cd99-4190-b831-d87ad363626d
date added to LUP
2025-09-23 21:55:00
date last changed
2025-10-09 10:56:20
@misc{68a1dc37-cd99-4190-b831-d87ad363626d,
  abstract     = {{One of the most anticipated properties of high entropy alloys (HEA) is excellent oxidation resistance. AlxCoCrFeNi (x=0,0.3,0.6,1 mole) HEAs were synthesized by arc melting route, followed by 4 remelting operations to ensure compositional homogenization. Alloys with x = 0 and 0.3 show single phase FCC structure and x = 1 have intricate BCC+B2 structure, whereas x = 0.6 have dual phases – FCC and BCC. Subjected to oxidation in air at 1000°C and 1150°C for 24 hours, CoCrFeNi (x = 0) developed a continuous Cr2O3 layer, while for Al0.3CoCrFeNi, aCr2O3 surface layer and internal Al2O3 was observed. Under the same test conditions, AlCoCrFeNi exhibited a continuous protective Al2O3 surface layer. Al0.6CoCrFeNi having dual phase structure develops Cr2O3 surface and internal Al2O3 over FCC dendritic regions and single Al2O3 surface oxide layer over the BCC interdendritic region. Oxidation resistance increases with increase in Al content. AlCoCrFeNi shows the best oxidation resistance, with a 5 micron thick, adherent, continuous and protective Al2O3 surface layer even at 0.89T m (1150°C) when exposed for<br/>24h. The oxidation resistance of Al0.6CoCrFeNi and AlCoCrFeNi synthesized by arc<br/>melting is far superior to that of Inconel 718 and Inconel 600 superalloys, in terms of oxide layer thickness, adherence, stability and protective behavior. This is due to their higher Al content, which remains dissolved in the alloy phases, owing to configurational entropy stabilization.}},
  author       = {{Bhattacharya, Rahul and Murty, B.S. and Fabijanic, Daniel and Hodgson, Peter}},
  keywords     = {{High entropy alloys; oxidation behaviour; Mechanical alloying; Spark plasma sintering; High resolution transmission electron microscopy; Scanning electron microscope (SEM); X ray diffraction; EDS; EBSD; Scanning Transmission Electron Microscopy; GDOES; Powder metallurgy (PM); Physical Metallugy; Thermodynamics and kinetics; Sintering; Microstructural evolution; Mechanical properties; Annealing; Heat treatment; Casting; Furnace control; CALPHAD}},
  language     = {{eng}},
  title        = {{Effect of Al content on oxidation behavior of AlxCoCrFeNi (x=0,0.3,0.6,1mole) arc-melted high entropy alloys}},
  year         = {{2016}},
}