Corrosion resistance of pseudo-high entropy Fe-containing amorphous alloys in chloride-rich media

Author(s):Show less -

Koga, G. Y. ^[1] ; Travessa, D. ^[2] ; Zepon, G. ^[1] ; Coimbrao, D. D. ^[1] ; Jorge, Jr., A. M. ^{[1, 3]} ; Berger, J. E. ^[1] ; Roche, V. ^[3] ; Lepretre, J. -c. ^[3] ; Bolfarini, C. ^[1] ; Kiminami, C. S. ^[1] ; Wang, F. ^[4] ; Zhu, S. L. ^[4] ; Inoue, A. ^{[5, 6, 4]} ; Botta, W. J. ^[1]

Affiliation

^[1] Univ Fed Sao Carlos, Dept Mat Sci & Engn, Rod Washington Luis, BR-13565905 Sao Carlos, SP - Brazil

^[2] Univ Fed Sao Paulo, Inst Sci & Technol, BR-12231280 Sao Jose Dos Campos, SP - Brazil

^[3] Univ Grenoble Alpes, Univ Savoie Mont Blanc, CNRS, Grenoble INP, LEPMI, Inst Engn & Management, F-38000 Grenoble - France

^[4] Tianjin Univ, Mat Sci & Engn Sch, Tianjin 300072 - Peoples R China

^[5] Josai Int Univ, Int Inst Green Mat, Togane 2838555 - Japan

^[6] China Univ Min Technol, Inst Mass Amorphous Met Sci, Xuzhou 221116, Jiangsu - Peoples R China

• Document type: Journal article
• Source: Journal of Alloys and Compounds; v. 884, DEC 5 2021.
• Web of Science Citations: 0

Abstract

Pseudo-high entropy (PHE) amorphous alloys have emerged as novel metallic materials. Some Fe-containing PHE amorphous alloys display the unique characteristic of maintaining a clustered glassy structure in a wide temperature range, and eventually crystallize multi-principal element (MPE) phases whose composition is close to the parental alloy composition. Therefore, these PHE amorphous alloys promise to surpass the trade-off between crystallization and corrosion resistance typical of most bulk metallic glasses. This work investigates the corrosion resistance in chloride media of (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)(100-x)B-x (x = 8, 10, 12 ) alloys produced by melt-spinning. The B-richest composition, (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)(88)B-12, ensured fully amorphous ribbons, while MPE nanocrystals were formed within the amorphous (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)90B(10) and (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)(92)B-8 ribbons. All alloys were corrosion-resistant in acidic (pH 3) and alkaline (pH 10) chloride-rich electrolyte (35 g L-1 NaCl) and in a hypersaline medium (250 g L-1 NaCl, pH 3), as verified from potentiodynamic polarization and electrochemical impedance spectroscopy measurements. From x-ray photoelectron spectroscopy, the formation of a nanometric-thick film composed of Fe-, Co-, Ni-, Cr-, and Mo- compounds on the alloys' surface was observed, responsible for granting the corrosion resistance of all alloys. Although containing crystals, the B-poorest alloy, (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)(92)B-8, presented comparable and even superior corrosion resistance than the fully amorphous B-richest alloy, (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)(88)B-12. The maintenance of the corrosion resistance of the (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)(90)B-10 and (Fe0.25Co0.25Ni0.25Cr0.125Mo0.125)(92)B-8 alloys in the presence of crystals were ascribed to the reduced elemental partition upon crystallization of MPE phases. The excellent corrosion resistance nevertheless vanished if excessive crystallization occurs, forming borides. These findings open new prospects for overcoming the corrosion-wear resistance paradigm of amorphous crystalline alloys, essential to design materials and coatings to endure harsh environments. (C) 2021 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 17/09237-4 - Design and production of spray-formed boron-modified stainless steels with high corrosion and wear resistance
• Grantee: Guilherme Yuuki Koga
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 13/05987-8 - Processing and characterization of amorphous, metastable and nano-structured metallic alloys
• Grantee: Claudio Shyinti Kiminami
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 18/21403-0 - Development of advanced low b content Fe-based amorphous and nanostructured high entropy alloys for coating applications
• Grantee: Walter José Botta Filho
• Support Opportunities: Research Grants - Visiting Researcher Grant - International