Surface Roughness Effect on Turbine Blade Erosion Due to Micro-Sized Particle Impact

Abstract The development of erosion-resistant coatings requires the knowledge of their complex failure mechanisms. Here, the damage due to erosion on smooth and rough surfaces is investigated and compared experimentally and numerically. In a low-speed collision, the smooth surface damage is always symmetrical. Still, the rough surface damage is different depending on the shape of the impact location, and there is no symmetry. In a high-speed collision, there is no difference between the rough and smooth surfaces because the particle energy is high enough to destroy the surface roughness. The effect of particle parameters on gas turbine blade erosion is investigated. For this purpose, the damage to the turbine blade is evaluated using scanning electron microscope (SEM) images. The results show that particle size is an effective parameter in gas turbine blade erosion, more than particle velocity (2.37 times) and particle density (3.21 times). Furthermore, the vertical impact on the rough surface is like an oblique impact on the smooth surface regarding the erosion rate. The relationship between particle parameters, including particle size, density, and velocity, with the particle's kinetic energy is analytically expressed.