Wear and Corrosion Behaviour of Supersaturated Surface Layers in the High-Entropy Alloy Systems CrMnFeCoNi and CrFeCoNi
Materials and Surface Engineering Group, Institute of Materials Science and Engineering,
Chemnitz University of Technology, D-09107 Chemnitz, Germany
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Crystals 2020, 10(2), 110; https://doi.org/10.3390/cryst10020110
Received: 22 January 2020 / Revised: 7 February 2020 / Accepted: 10 February 2020 / Published: 12 February 2020
(This article belongs to the Special Issue Development of High Entropy Alloys)
The surface hardening of single-face-centred cubic (fcc)-phase CrMnFeCoNi and the manganese-free CrFeCoNi alloy was conducted using low-temperature nitrocarburisation. The microstructural investigations reveal the successful formation of a homogeneous diffusion layer with a thickness of approximately 16 µm. The interstitial solution of carbon and nitrogen causes an anisotropic lattice expansion. The increase in microhardness is in accordance to the graded concentration profile of the interstitial elements. Wear tests show a significantly enhanced resistance at different loads. The electrochemical tests reveal no deterioration in the corrosion resistance. The absence of precipitates is proven by microstructural investigations. The results prove the applicability of the concept of solution hardening by the formation of supersaturated solutions for the material group of high-entropy alloys. Hence, an increase of entropy with the consideration of lattice interstices provides new development approaches.
Keywords:
high-entropy alloy; thermochemical treatment; surface hardening; supersaturated solution; wear; corrosion
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MDPI and ACS Style
Lindner, T.; Löbel, M.; Saborowski, E.; Rymer, L.-M.; Lampke, T. Wear and Corrosion Behaviour of Supersaturated Surface Layers in the High-Entropy Alloy Systems CrMnFeCoNi and CrFeCoNi. Crystals 2020, 10, 110.
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