Effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys in CO2/CO mixed gases

Wu Kai; Yen-che Wang; Yu-jing Huang; Kuan-yuan Lu; Wei-bing Wang; Yinghao Zhou; Ji-jung Kai

doi:10.1016/j.jallcom.2025.179952

Effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys in CO₂/CO mixed gases

Wu Kai^*
, Yen-che Wang
, Yu-jing Huang
, Kuan-yuan Lu
, Wei-bing Wang
, Yinghao Zhou
, Ji-jung Kai

^*Corresponding author for this work

Department of Mechanical Engineering

Research output: Journal Publications and Reviews › RGC 21 - Publication in refereed journal › peer-review

1 Citation (Scopus)

Abstract

The effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys containing FeCoNi, FeCoNiCr, and FeCoNiCrAl_0.3 were studied at 600–950 ℃ in a 9:1 CO₂/CO gas mixture. The oxidation kinetics of all three alloys obeyed the parabolic-rate law, and their oxidation rates steadily increased with temperature. The scales formed on FeCoNi consisted of an intermixed layer of CoO and Fe₃O₄ and internal FeO precipitates (observed at 950 ℃). Those formed on FeCoNiCr consisted of an outer layer of CoNiO₂ intermixed with FeCoCrO₄ and an inner layer of Cr₂O₃. The scale formed on FeCoNiCrAl_0.3 was strongly temperature-dependent, consisting of discontinuous Cr₂O₃ granules at 600℃, internal Al₂O₃ precipitates formed beneath a Cr₂O₃ layer at 760 ℃, and an exclusive α-Al₂O₃ layer at 950 ℃. © 2025 Elsevier B.V.

Original language	English
Article number	179952
Journal	Journal of Alloys and Compounds
Volume	1022
Online published	24 Mar 2025
DOIs	https://doi.org/10.1016/j.jallcom.2025.179952
Publication status	Published - 10 Apr 2025

Funding

Financial support by the National Science and Technology Council of the Republic of China under Grant Nos. of NSTC 113-2221-E-019-014 and 113-2224-E-131-001 is greatly acknowledged. Prof. Wu Kai is also thankful for the partial funding support by the Hong Kong Research Grant Council under Grant Nos. CityU C1017-21G, 11209021, and 11214423 and the Centre for Advanced Nuclear Safety and Sustainable Development under Grant No. 9600011 during his visit to the City University of Hong Kong.

Research Keywords

CoO
Cr2O3
Fe3O4
FeCoCrO4
FeCoNi-based medium- and high-entropy alloys
NiCoO2
α-Al2O3

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10.1016/j.jallcom.2025.179952

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title = "Effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys in CO2/CO mixed gases",

abstract = "The effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys containing FeCoNi, FeCoNiCr, and FeCoNiCrAl0.3 were studied at 600–950 ℃ in a 9:1 CO2/CO gas mixture. The oxidation kinetics of all three alloys obeyed the parabolic-rate law, and their oxidation rates steadily increased with temperature. The scales formed on FeCoNi consisted of an intermixed layer of CoO and Fe3O4 and internal FeO precipitates (observed at 950 ℃). Those formed on FeCoNiCr consisted of an outer layer of CoNiO2 intermixed with FeCoCrO4 and an inner layer of Cr2O3. The scale formed on FeCoNiCrAl0.3 was strongly temperature-dependent, consisting of discontinuous Cr2O3 granules at 600℃, internal Al2O3 precipitates formed beneath a Cr2O3 layer at 760 ℃, and an exclusive α-Al2O3 layer at 950 ℃. {\textcopyright} 2025 Elsevier B.V.",

keywords = "CoO, Cr2O3, Fe3O4, FeCoCrO4, FeCoNi-based medium- and high-entropy alloys, NiCoO2, α-Al2O3",

author = "Wu Kai and Yen-che Wang and Yu-jing Huang and Kuan-yuan Lu and Wei-bing Wang and Yinghao Zhou and Ji-jung Kai",

year = "2025",

month = apr,

day = "10",

doi = "10.1016/j.jallcom.2025.179952",

language = "English",

volume = "1022",

journal = "Journal of Alloys and Compounds",

issn = "0925-8388",

publisher = "Elsevier B.V.",

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TY - JOUR

T1 - Effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys in CO2/CO mixed gases

AU - Kai, Wu

AU - Wang, Yen-che

AU - Huang, Yu-jing

AU - Lu, Kuan-yuan

AU - Wang, Wei-bing

AU - Zhou, Yinghao

AU - Kai, Ji-jung

PY - 2025/4/10

Y1 - 2025/4/10

N2 - The effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys containing FeCoNi, FeCoNiCr, and FeCoNiCrAl0.3 were studied at 600–950 ℃ in a 9:1 CO2/CO gas mixture. The oxidation kinetics of all three alloys obeyed the parabolic-rate law, and their oxidation rates steadily increased with temperature. The scales formed on FeCoNi consisted of an intermixed layer of CoO and Fe3O4 and internal FeO precipitates (observed at 950 ℃). Those formed on FeCoNiCr consisted of an outer layer of CoNiO2 intermixed with FeCoCrO4 and an inner layer of Cr2O3. The scale formed on FeCoNiCrAl0.3 was strongly temperature-dependent, consisting of discontinuous Cr2O3 granules at 600℃, internal Al2O3 precipitates formed beneath a Cr2O3 layer at 760 ℃, and an exclusive α-Al2O3 layer at 950 ℃. © 2025 Elsevier B.V.

AB - The effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys containing FeCoNi, FeCoNiCr, and FeCoNiCrAl0.3 were studied at 600–950 ℃ in a 9:1 CO2/CO gas mixture. The oxidation kinetics of all three alloys obeyed the parabolic-rate law, and their oxidation rates steadily increased with temperature. The scales formed on FeCoNi consisted of an intermixed layer of CoO and Fe3O4 and internal FeO precipitates (observed at 950 ℃). Those formed on FeCoNiCr consisted of an outer layer of CoNiO2 intermixed with FeCoCrO4 and an inner layer of Cr2O3. The scale formed on FeCoNiCrAl0.3 was strongly temperature-dependent, consisting of discontinuous Cr2O3 granules at 600℃, internal Al2O3 precipitates formed beneath a Cr2O3 layer at 760 ℃, and an exclusive α-Al2O3 layer at 950 ℃. © 2025 Elsevier B.V.

KW - CoO

KW - Cr2O3

KW - Fe3O4

KW - FeCoCrO4

KW - FeCoNi-based medium- and high-entropy alloys

KW - NiCoO2

KW - α-Al2O3

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U2 - 10.1016/j.jallcom.2025.179952

DO - 10.1016/j.jallcom.2025.179952

M3 - RGC 21 - Publication in refereed journal

SN - 0925-8388

VL - 1022

JO - Journal of Alloys and Compounds

JF - Journal of Alloys and Compounds

M1 - 179952

ER -

Effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys in CO₂/CO mixed gases

Abstract

Funding

Research Keywords

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GRF: Irradiation Resistance and Microstructural Stability of Chemically Complex Intermetallic Alloys

ResCtrs: College of Engineering Research Centre for Advanced Nuclear Safety and Sustainable Development (ANSD)

CRF: Designing Self-healing High Entropy Alloys for Advanced Nuclear Applications

Cite this

Effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys in CO2/CO mixed gases

Abstract

Funding

Research Keywords

RGC Funding Information

Access Output

Other Access Options

Permanent Link

Other Files and Links

Fingerprint

Projects

GRF: Irradiation Resistance and Microstructural Stability of Chemically Complex Intermetallic Alloys

ResCtrs: College of Engineering Research Centre for Advanced Nuclear Safety and Sustainable Development (ANSD)

CRF: Designing Self-healing High Entropy Alloys for Advanced Nuclear Applications

Cite this

Effects of Cr and Al additions on the oxidation of FeCoNi-based medium- and high-entropy alloys in CO₂/CO mixed gases