A comprehensive study on hot corrosion resistance of NiCoCrAlYTa and NiCrAl thermal-sprayed coatings for CSP applications

The new generation of concentrated solar power (CSP) plants could be able to work at temperatures up 650 °C and carbonates molten salts are one of the main candidates to be used as thermal energy storage (TES) materials. Molten salt corrosion has been defined as one of the main issues and the techno...

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Detalles Bibliográficos
Autores: Aristu Ojer, Daniel, Berlanga Labari, Carlos, Alberro, Mikel, Rández Diago, Xabier, Fernández, Ángel G.
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2023
País:España
Institución:Universidad Pública de Navarra
Repositorio:Academica-e. Repositorio Institucional de la Universidad Pública de Navarra
OAI Identifier:oai:academica-e.unavarra.es:2454/48020
Acceso en línea:https://hdl.handle.net/2454/48020
Access Level:acceso abierto
Palabra clave:Carbonate molten salts
Concentrated solar power
Hot corrosion
Thermal-sprayed coatings
Descripción
Sumario:The new generation of concentrated solar power (CSP) plants could be able to work at temperatures up 650 °C and carbonates molten salts are one of the main candidates to be used as thermal energy storage (TES) materials. Molten salt corrosion has been defined as one of the main issues and the technology demands more resistance alloys and innovative coatings. In this study, the assessment of hot corrosion resistance for NiCoCrAlYTa and NiCrAl thermal-sprayed coatings has been undertaken, tested on a ternary eutectic mixture (Li2CO3-Na2CO3-K2CO3) at a temperature of 650 °C. Electrochemical impedance spectroscopy and linear polarization resistance tests were used to evaluate the behaviour of the coatings but the obtained results reveal high values of corrosion rates accompanied by the formation of cracks. This unsatisfactory performance of the coatings, analysed by scanning electron microscopy and x-ray diffraction, can be attributed to a combination of different factors such as porosity, internal material stresses and thermal diffusion phenomena. As a result, it is concluded that further research is necessary to explore new coating application techniques.