2023 Bidmeshki Thermally Sprayed Wear Resistant Coatings Thesis

Thermal sprayed tribological coatings have been used extensively in aerospace applications, primarily to overcome critical challenges such as abrasive wear, corrosion, erosion, oxidation and fatigue at high temperatures and pressures. Such coatings can also play a critical role in optimizing the efficiency and lifespan of aerospace components. This study focuses on the microstructural, mechanical, and tribological evaluation of two different thermally sprayed coatings: Ni-Graphite and Cu-Al. The methodology involved detailed characterization of the coatings, followed by tribological testing under simulated aerospace conditions. Results indicated that at elevated temperatures, the Ni-Graphite coatings demonstrated superior wear resistance and lower friction compared to the Cu-Al coatings, suggesting that the presence of graphite-based solid lubricants in the Ni-Graphite composition is integral to its improved performance. Furthermore, it was observed that the hardness of the coatings alone did not predict their wear behavior, indicating that interfacial processes play a more significant role. Finally, recommendations for future work include optimization of spraying parameters and advanced tribological evaluation under application-relevant conditions.