Abstract
NiCoCrAlY/ZrB2–B4C composite coatings were prepared by atmospheric plasma spraying using a clad powder and their microstructure, phase composition and mechanical properties were characterized. The friction and wear behavior of the coatings were evaluated from room temperature to 800°C in dry air and water vapor atmospheres using a ball-on-disk tribometer. The results show that the NiCoCrAlY/ZrB2–B4C composite coating exhibited low porosity (6.7±0.8%), high Rockwell hardness (HR45y82±5) and high cohesive strength (18±3MPa), as well as good friction and excellent anti-wear ability up to 800°C. The friction coefficients and wear rates of the coating under water vapor ambience were lower than that under dry air. The main reason is the synergistic effect of layer structured lubricating H3BO3 and molten B2O3 films, which were produced by the reaction of the boride with O2 and H2O in the water vapor atmosphere.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call