Abstract
This study systematically examines the influence of high-velocity oxygen-fuel (HVOF) spraying parameters, with particular emphasis on oxygen pressure, on the microstructure and tribological performance of Al65Cu20Fe15 coatings. The coatings were deposited at two oxygen pressures (3.0 and 3.5 bar), while all other spraying parameters remained constant. Microstructural characterization was performed using scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS), and phase composition was analyzed to assess the proportion of quasi-crystalline and crystalline phases. Tribological behavior was assessed using a ball-on-disk sliding test with continuous friction coefficient recording. The results show that oxygen pressure significantly influences coating density, phase composition, and tribofilm formation. The coating deposited by spraying at an oxygen pressure of 3.5 bar demonstrated the most balanced characteristics, with a stable friction coefficient of 0.55–0.60 and consistent wear, which is explained by a higher proportion of the quasicrystalline phase and a homogeneous tribofilm. Thus, the analysis revealed that processing the samples at 3.5 bar oxygen pressure is the optimal process mode, ensuring the formation of a denser microstructure and improved tribological properties of the coating.