Nitriding of CoCrFeNi medium entropy alloys: Characterization and tribocorrosion behaviour

Abstract

The microstructure and formation mechanism of a plasma-nitrided medium-entropy CoCrFeNi alloy, which was produced via arc melting, were examined, along with the tribocorrosion behaviour of both the unterated and the nitrided alloy. The presence of CrN and expanded FCC in the nitrided alloy was clearly observed. The nitride layer exhibited an approximate thickness of 27 mu m (+/- 5.3 mu m). Tribocorrosion results conclusively demonstrated that the nitrided alloy displayed a superior resistance to both corrosion and erosion when compared to the untreated alloy. The findings from Rockwell indentation tests confirmed that the adhesion between the nitride layer and the substrate was notably strong.