Effect of Cr and Al on phase constitution and high temperature oxidation behavior of Al-Co-Cr-Fe-Ni high entropy alloys
(2023)- Abstract
- In this thesis, the inherent oxidation resistance of Al-Co-Cr-Fe-Ni based high entropy alloys have been remarkably enhanced by increasing the grain boundary area and recognizing the influence of the in situ Al2O3 nano-dispersoids. Isothermal continuous oxidation test based on thermogravimetric analysis (TGA) as well as extensive furnace oxidation, were conducted in the elevated temperature range of 850-1150℃ (1 atm) for 5-200h duration to investigate the
thermodynamical driving force and kinetics associated with various stages of oxidation.
According to Ellingham diagrams, Al followed by Cr have the highest affinity towards oxygen in the temperature and pressure range discussed above.
Nine HEA compositions based on... (More) - In this thesis, the inherent oxidation resistance of Al-Co-Cr-Fe-Ni based high entropy alloys have been remarkably enhanced by increasing the grain boundary area and recognizing the influence of the in situ Al2O3 nano-dispersoids. Isothermal continuous oxidation test based on thermogravimetric analysis (TGA) as well as extensive furnace oxidation, were conducted in the elevated temperature range of 850-1150℃ (1 atm) for 5-200h duration to investigate the
thermodynamical driving force and kinetics associated with various stages of oxidation.
According to Ellingham diagrams, Al followed by Cr have the highest affinity towards oxygen in the temperature and pressure range discussed above.
Nine HEA compositions based on Al-Co-Cr-Fe-Ni system were synthesized by
systematically varying the nominal content of Al and Cr. These nine HEAs have been recognized into three groups based on Al or Cr variation viz. equiatomic HEAs (CoCrFeNi, AlCoFeNi, and AlCoCrFeNi), non-equiatomic Cr-variation HEAs (AlCoCr0.25FeNi, AlCoCr0.50FeNi, and AlCoCr0.75FeNi), as well as non-equiatomic Al-variation HEAs (Al0.25CoCrFeNi, Al0.50CoCrFeNi, and Al0.75CoCrFeNi). (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/8a4fa4ad-0268-49d1-8d43-e0078614e5a3
- author
- Bhattacharya, Rahul LU
- supervisor
- publishing date
- 2023-06
- type
- Thesis
- publication status
- published
- subject
- keywords
- Al-Co-Cr-Fe-Ni Based HEAs, Mechanical alloying, Spark plasma sintering, Bimodal grain size distribution, Process optimization, Grain boundary efect
- pages
- 285 pages
- language
- English
- LU publication?
- no
- additional info
- Joint doctoral program (JDP): IIT Madras-Deakin University, Australia JDP Received Res-part scholarship and conducted the high temperature oxidation as well as elaborate post-oxidation characterization section of Thesis research in collaboration with Institute for Frontier Materials at Deakin University under the supervision of Prof. Daniel Fabijanic. The alloy design and process design were entirely conducted at the Department of MME at IIT Madras under the supervision of Prof. B. S. Murty (Director IIT Hyderabad).
- id
- 8a4fa4ad-0268-49d1-8d43-e0078614e5a3
- date added to LUP
- 2025-08-31 12:16:11
- date last changed
- 2025-09-22 16:30:39
@phdthesis{8a4fa4ad-0268-49d1-8d43-e0078614e5a3, abstract = {{In this thesis, the inherent oxidation resistance of Al-Co-Cr-Fe-Ni based high entropy alloys have been remarkably enhanced by increasing the grain boundary area and recognizing the influence of the in situ Al2O3 nano-dispersoids. Isothermal continuous oxidation test based on thermogravimetric analysis (TGA) as well as extensive furnace oxidation, were conducted in the elevated temperature range of 850-1150℃ (1 atm) for 5-200h duration to investigate the<br/>thermodynamical driving force and kinetics associated with various stages of oxidation.<br/><br/>According to Ellingham diagrams, Al followed by Cr have the highest affinity towards oxygen in the temperature and pressure range discussed above.<br/>Nine HEA compositions based on Al-Co-Cr-Fe-Ni system were synthesized by<br/>systematically varying the nominal content of Al and Cr. These nine HEAs have been recognized into three groups based on Al or Cr variation viz. equiatomic HEAs (CoCrFeNi, AlCoFeNi, and AlCoCrFeNi), non-equiatomic Cr-variation HEAs (AlCoCr0.25FeNi, AlCoCr0.50FeNi, and AlCoCr0.75FeNi), as well as non-equiatomic Al-variation HEAs (Al0.25CoCrFeNi, Al0.50CoCrFeNi, and Al0.75CoCrFeNi).}}, author = {{Bhattacharya, Rahul}}, keywords = {{Al-Co-Cr-Fe-Ni Based HEAs; Mechanical alloying; Spark plasma sintering; Bimodal grain size distribution; Process optimization; Grain boundary efect}}, language = {{eng}}, title = {{Effect of Cr and Al on phase constitution and high temperature oxidation behavior of Al-Co-Cr-Fe-Ni high entropy alloys}}, year = {{2023}}, }