Microstructure and tribological performance of FeCoNiCrAl high-entropy alloy coatings: role of laser scanning speed

FeCoNiCrAl HEA coatings were fabricated on 45 steel using laser cladding (LC) with different laser scanning speeds (LSSs), and the influences of LSS on the structural evolution, phase transitions and tribological performance were systematically investigated, providing guidance for optimising the structure and tribological properties of HEA coatings through LSS control. The systematic experimental approach was employed, and the detailed characterisation techniques were applied to analyse their microstructural features, mechanical properties and wear behaviour. The results indicate that the grain sizes of FeCoNiCrAl HEA coatings are decreased as the LSS increases, and the microstructure becomes more refined, while the porosity is increased. The HEA coatings primarily consist of body-centred cubic (BCC) phases, and the appropriate LSS enhances their hardness and wear resistance due to the refined grains and more uniform microstructure. Furthermore, the HEA coatings exhibit the lower coefficients of friction (COFs) and reduced wear rates, which contribute to advancing the tribological performance of HEA coatings.