High-temperature wear behavior of Tribaloy T400 and T800 coatings prepared by a novel ethanol-fueled HVOF process

In this work, Tribaloy T400 and T800 coatings were prepared on 304 stainless steel substrates using a novel ethanol-fueled HVOF process, which is a recently developed liquid fuel HVOF technology. Two sets of spraying parameters, namely E1 and E2, with different oxygen/ethanol ratio were selected in order to obtain dense and high-quality coatings for high-temperature tribological testing. Moreover, the high-temperature wear behavior of the as-sprayed coatings prepared by this new process was studied. The results showed that the T400-E1 and T800-E2 coatings had the highest microhardness and the lowest porosity. Both coatings displayed wear rates of 5.92 × 10⁻⁴ and 2.74 × 10⁻⁴ mm³ N⁻¹ m⁻¹ in the sliding wear tests performed at room temperature, respectively. The T800 coatings exhibited better wear resistance due to their high contents of Laves phase and Cr. High temperature sliding wear tests were carried out at 400 °C and 800 °C, respectively. It can be inferred that the wear mechanism of the T400 coating at 400 °C mainly consists in oxidative and abrasive wear, whereas that of the T800 coating at 800 °C can be described mainly as oxidative wear with peeling.