High-Speed Rubbing Behavior Between Nickel-Based Superalloy Blades and Ceramic-Based Abradable Coatings

The tribological behavior of nickel-based superalloy blades with YSZ ceramic-based abradable coatings was investigated using a self-developed high-speed rubbing tester, focusing on the effect of working parameters (linear velocity and incursion rate) on blade and coating wear mechanisms. A non-contact infrared thermometer and a high-speed camera were used to determine real-time changes in coating surface temperature and blade length. The wear morphology and elemental composition of the blade and coating were characterized by a scanning electron microscope, an ultra-depth three-dimensional microscope, and an energy spectrometer. The test results showed that at the same incursion rate, the variation of blade wear length exhibited a tendency of first increasing and then decreasing with the increase of linear velocity. The maximum degree of blade wear was reached at 200 m/s. There was no significant correlation between the degree of blade wear and the incursion rate at the same linear velocity. The linear velocity was the primary influence on driving friction, while the incursion rate became a secondary factor, contrary to the well-known law in metal-based abradable coatings. The main forms of damage to blades included grooving, overheating, and micro-rupture. Plastic removal was the main wear mechanism for blades. The wear mechanism of ceramic-based abradable coatings was mainly characterized by subsurface cracking. The brittle removal of the coating resulted in "stepped" wear of the blade and a short actual action time of the friction pair. In this paper, the wear mechanisms of nickel-based superalloy blades and ceramic-based abradable coatings were mapped for the first time.