Cavitation and abrasion resistance of Ti–Al–Y–N coatings prepared by the PIII&D technique from filtered vacuum-arc plasma

In the present work we examined the cavitation and abrasion resistance of PIII&D Ti–Al–Y–N coatings with Y content ≤ 1 at.% and analyzed the influence of mechanical properties and structure of the coatings on their wear resistance. The coatings with thickness of 5–6 μm were deposited on the polished stainless steel (type-302) substrates by filtered vacuum-arc evaporation technique. The substrate potential was either DC with a constant voltage of − 150 V or pulsed DC with an amplitude AU in the range of 0–2.5 kV. The cavitation treatment of the coating deposited at the DC potential resulted in long cracks on their surface. The coating deposited at AU = 0 was subjected to pitting erosion. The high voltage pulsed substrate potential contributed to the decrease in the rate of mass loss under cavitation, at the same time the quantity of erosion defects on the treated surface was strongly diminished. The increase of Y content resulted in improvement of wear durability. Average rates of cavitation and abrasion wear of (Ti,Al)N + 1 at.%Y were a factor of 3 to 5 times lower than that of (Ti,Al)N and tenfold lower than that of TiN. Formation of a dense nanostructure with fine grains and non-evident (inapparent) columnar morphology, significant reduction in the surface roughness and decrease in the internal stress level are the reasons for the improved wear resistance.