Phase Evolution and Microstructure Analysis of CoCrFeNiMo High-Entropy Alloy for Electro-Spark-Deposited Coatings for Geothermal Environment
| Autor: | Radu Stefanoiu, Laura Elena Geambazu, Andri Isak Thorhallsson, Ioana Csaki, Fridrik Magnus, Cosmin Mihai Cotrut, Sigrun Nanna Karlsdottir |
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| Přispěvatelé: | Iðnaðarverkfræði-, vélaverkfræði- og tölvunarfræðideild (HÍ), Faculty of Industrial Eng., Mechanical Eng. and Computer Science (UI), Science Institute (UI), Raunvísindastofnun (HÍ), Verkfræði- og náttúruvísindasvið (HÍ), School of Engineering and Natural Sciences (UI), Háskóli Íslands, University of Iceland |
| Jazyk: | angličtina |
| Předmět: |
Materials science
Scanning electron microscope XRD Alloy microstructure high-entropy alloy 02 engineering and technology engineering.material 01 natural sciences 7. Clean energy geothermal environment Electro-spark deposition Corrosion Coating Phase (matter) Tæring málma 0103 physical sciences Materials Chemistry High-entropy alloy Composite material Microstructure 010302 applied physics corrosion coating Surfaces and Interfaces Vacuum arc 021001 nanoscience & nanotechnology Surfaces Coatings and Films Málmfræði 13. Climate action lcsh:TA1-2040 Electrode Geothermal environment engineering 0210 nano-technology lcsh:Engineering (General). Civil engineering (General) electro-spark deposition Jarðhitasvæði |
| Zdroj: | Coatings Volume 9 Issue 6 Coatings, Vol 9, Iss 6, p 406 (2019) |
| ISSN: | 2079-6412 |
| DOI: | 10.3390/coatings9060406 |
| Popis: | Publisher's version (útgefin grein) In this work, a CoCrFeNiMo high-entropy alloy (HEA) material was prepared by the vacuum arc melting (VAM) method and used for electro-spark deposition (ESD). The purpose of this study was to investigate the phase evolution and microstructure of the CoCrFeNiMo HEA as as-cast and electro-spark-deposited (ESD) coating to assess its suitability for corrosvie environments encountered in geothermal energy production. The composition, morphology, and structure of the bulk material and the coating were analyzed using scanning electron microscopy (SEM) coupled with energy-dispersive spectroscopy (EDS), and X-ray diffraction (XRD). The hardness of the bulk material was measured to access the mechanical properties when preselecting the composition to be pursued for the ESD coating technique. For the same purpose, electrochemical corrosion tests were performed in a 3.5 wt.% NaCl solution on the bulk material. The results showed the VAM CoCrFeNiMo HEA material had high hardness (593 HV) and low corrosion rates (0.0072 mm/year), which is promising for the high wear and corrosion resistance needed in the harsh geothermal environment. The results from the phase evolution, chemical composition, and microstructural analysis showed an adherent and dense coating with the ESD technique, but with some variance in the distribution of elements in the coating. The crystal structure of the as-cast electrode CoCrFeNiMo material was identified as face centered cubic with XRD, but additional BCC and potentially σ phase was formed for the CoCrFeNiMo coating. This work is part of the H2020 EU project Geo-Coat: Development of novel and cost-effective corrosion resistant coatings for high temperature geothermal applications. Call H2020-LCE-2017-RES-RIA-TwoStage (Project No. 764086). |
| Databáze: | OpenAIRE |
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