Abstract
Al-Cu-Fe quasicrystalline coatings were prepared using high-velocity oxygen-fuel spray technique. The influence of the O2/Fuel (O/F) ratio on the microstructure and porosity level of the coatings was investigated by scanning electron microscopy, X-ray diffraction, and Vickers microhardness measurements. The coating is predominantly (almost ~100%) composed of quasicrystalline phase after a supplementary heat treatment at 700 °C for 5 min. The results indicate that the microstructure and properties of the coatings are sensitive to the O2/Fuel ratio. A coating with the highest hardness value combined with the lowest porosity is attainable for O/F ratio slightly below 1.1, i.e. the theoretical value for complete combustion of the kerosene fuel.
•The HVOF atmosphere has an effect on the microstructure and phase composition of AlCuFeB coatings.•Oxygen-to-fuel ratio around 0.98 provides coatings of the lowest porosity level (~1.5%).•Hardness of the HVOF thermal sprayed coatings is close to the hardness of the bulk AlCuFeB alloys.•Oxygen-to-fuel ratio has an effect on the value of the elastic modulus.•XPS spectra show traces of FeC compounds for all oxygen-to-fuel ratios.