Wear-corrosion resistance TiCN-based coatings

The composition, structure and properties of HVOF-coatings obtained under spraying of composite powders based on TiCN with SiC, AlN, SiC-AlN/Al2O3 additives are investigated. Metallographic, petrographic, XRD, EPMA and SEM analyses are applied for study of the working coating surfaces. The coatings of 200 μm thickness had a typical fine-dispersion lamellar structure with an alternation of layers, enriched with titanium, and Ni-Cr alloy, The developed coatings exceeded the standard WC+8% Co alloy on tribological characteristics: under dry friction at the load of 2 MPa and sliding velocities in the range of 5-15 m/s the friction coefficient is 0.17-0.11, wear - 3.4 - 8.5 μm/km. The high resistance to oxidation of the coatings materials is conditioned by availability in an outer scale layer of the Al2SiO5, (Cr,Al)2O3, Al2TiO5 high-temperature compounds preventing from oxygen diffusion into the base. The mass gain of the coating material for TiCN-SiC-AlN-based composite is 1.42 mg/cm2 at 1450°C.