Speaker
Description
High-Entropy Alloys (HEAs) show many fascinating properties such as high corrosion resistance and toughness, fatigue and wear resistance, high hardness and yield strengths, high thermal stability.
In particular, the combination of good corrosion-erosion resistance in saline environments of HEAs containing passivating elements was reported to be even superior to traditional alloys. Therefore, HEAs became attractive for applications such as offshore wind power plants, where materials are required to have a working life of tens of years in extreme conditions [2].
Sputtering techniques represents a promising approach because they allow depositing uniform thin films without elemental segregation and phase decomposition, thanks to the fast quenching and low diffusivity of elements, and tailorable crystallographic microstructures.
Moreover, the use of HEAs as coating materials could overcome the critical issue of the high bulk production cost.
In this work, HEA coatings were grown at room temperature on metallic and nonmetallic substrates commonly used in manufacturing offshore wind power plants. In particular, aluminum alloys, stainless steel, carbon fibers and fiberglass have been considered.
A High Power Impulse Magnetron Sputtering (HiPIMS) system was employed to produce FeNiCrM1M2 HEA coatings. HiPIMS has advantages such as increased film density, hardness and adhesion, lack of macro particles, which could favor the formation of preferential paths inside the film reducing corrosion resistance, and smooth surface, essential to improve fatigue resistance.
The samples obtained have been characterized via SEM, SEM-EDS, XRD, nanoindentation and potentiodynamic polarization tests in simulated marine environment.
References
1. E.P. George et al., Nat Rev Mater 4, (2019) 515. https://doi.org/10.1038/s41578-019-0121-4
2. Report: “State of the Art Study on Materials and Solutions against Corrosion in Offshore Structures - North Sea Solutions for Innovation in Corrosion for Energy”, 2018, European NeSSIE project www.nessieproject.com
| Speaker Country | Italy |
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