Mechanical, tribological, anti-corrosion and anti-glass sticking properties of high-entropy TaNbSiZrCr carbide coatings prepared using radio-frequency magnetron sputtering

High-entropy TaNbSiZrCr carbide coatings were deposited on WC substrates by radio-frequency unbalanced magnetron sputtering with C2H2 flow rates ranging from 0 to 23 sccm. The microstructure, mechanical properties, tribological properties and anti-corrosion resistance of the coatings were analyzed in both an as-sputtered condition and an annealed condition. The anti-glass sticking performance of the coatings was additionally investigated by annealing the coatings at 750 °C for 1 h on BK7 glass plates. The results showed that the as-sputtered and annealed coatings with a low carbon content (i.e., C2H2 flow rates lower than 8 sccm) had a high hardness (>34.1 GPa). The as-sputtered sample deposited with the maximum C2H2 flow rate (23 sccm) showed the best tribological properties of all the as-sputtered samples. However, the wear rate of the coating increased by a factor of around 10 times after annealing. The annealed coating nevertheless exhibited the highest corrosion resistance of all the coatings. Finally, the glass sticking results showed that the use of an appropriate C2H2 flow rate (4–12 sccm) was beneficial in enhancing the anti-glass-sticking performance of the coatings.