Effect of Barrel Filling Ratio on the Microstructure, Phase Composition and Tribological Performance of Detonation-Sprayed Cr3C2–NiCr Coatings

This study investigates the influence of barrel filling ratio on the microstructure, phase composition, and tribological performance of detonation-sprayed Cr3C2–NiCr coatings. Coatings were deposited at barrel filling ratios of 43% and 53% under identical spraying conditions. Microstructural characterization revealed the formation of dense lamellar coatings with low porosity and uniform distribution of Cr3C2 carbide particles within the NiCr metallic matrix. Compared with the coating deposited at a barrel filling ratio of 43%, the coating deposited at 53% exhibited a denser microstructure. X-ray diffraction analysis confirmed that Cr3C2 and NiCr remained the dominant phases after spraying, while a minor amount of Cr7C3 formed due to partial decarburization of chromium carbide during thermal exposure. Tribological performance was evaluated under dry sliding conditions using a ball-on-disc configuration at normal loads of 10 and 15 N and sliding speeds of 5 and 10 cm/s. Wear volume was determined from the geometry of the wear track after testing, and wear rate was calculated accordingly. The coating produced at a barrel filling ratio of 53% demonstrated improved wear resistance under elevated loads despite exhibiting a higher coefficient of friction. The minimum wear rate reached 1.23 × 10−4 mm3/(m·N), which was associated with reduced porosity and enhanced structural integrity of the coating. The obtained results demonstrate that optimization of detonation spraying parameters significantly affects coating structure and tribological behavior. The developed Cr3C2–NiCr coatings are promising protective materials for components operating under severe friction and wear conditions, including industrial and high-temperature engineering applications.