High-temperature tribological properties of APS-sprayed CoCrNiW wear-resistant coating and NiCoCrAlYTa/Cu/Mo self-lubricating coating

Utilizing atmospheric plasma spraying technology, we produced wear-resistant coatings of CoCrNiW and NiCoCrAlYTa/Cu/Mo self-lubricating composite coatings. The microstructures, mechanical properties, and high-temperature tribological properties were studied. The findings showed that both coatings demonstrated excellent tribological properties. As the temperature increased, the wear rate and coefficient of friction (COF) first rose and then fell. The COF for the CoCrNiW and NiCoCrAlYTa/Cu/Mo coatings were measured at 0.60 to 1.17 and 0.31 to 1.01, respectively, while their wear rates were found to be 0.60 to 2.50 × 10⁻⁵ mm³/N·m and 0.29 to 3.35 × 10⁻⁵ mm³/N·m. At 600 ℃, the wear track surface of the CoCrNiW coating was covered by a glaze layer, and the wear mechanism shifted from abrasive wear to adhesive wear, thereby reducing wear severity as the temperature rose. In contrast, the NiCoCrAlYTa/Cu/Mo composite coating developed a glaze layer containing self-lubricating phases at 800 ℃, effectively diminishing abrasive wear, thus showing better wear resistance than CoCrNiW coating.