N-doping significantly enhances resistance of CrCoNi medium-entropy alloy towards microbiologically influenced corrosion and tribocorrosion in the presence of Shewanella algae

A novel nitrogen (N)-doped CrCoNi medium-entropy alloy (MEA) with high resistance to microbiologically influenced corrosion and tribocorrosion was manufactured through a pressurized metallurgy technique. The results indicated that the N-doped MEA displayed a low corrosion rate and pitting corrosion sensitivity in the presence of corrosive microorganism Shewanella algae. N enriched in passive film, reduced its defect density and increased the fraction of corrosion resistant Cr2O3. In addition, N-doping significantly improved the hardness and inhibited tribocorrosion of MEA-1.75N alloy in both abiotic and biotic artificial seawater. N-doping provided novel insight into the design of MEAs with high corrosion and tribocorrosion resistance.