Effect of scanning speed on microstructure and wear resistance of AlFeNb0.5NiTi high-entropy alloy coatings by laser cladding

AlFeNb0.5NiTi high-entropy alloy (HEA) coatings were prepared on Cr12MoV by laser cladding. The effect of scanning speed on the microstructure and wear resistance of the coatings was studied. The results showed that the phase of AlFeNb0.5NiTi coatings was composed of a BCC solid solution, Fe2Nb, and NbTiC2, at different scanning speeds. With the increase in scanning speed, the microstructure of the coating changes from the network eutectic structure to short rod-shaped grain morphology. Due to the combined effects of grain refining strengthening, solid solution strengthening, and dispersion strengthening, compared with the substrate, the microhardness of AlFeNb0.5NiTi coatings increased by 145.22%–298.70% and the wear volumes decreased by 67.37%–87.25%. At the scanning speed of 360 mm/min, the AlFeNb0.5NiTi coating had the best wear resistance. The wear mechanisms of the coating were abrasive wear, fatigue wear, and oxidation wear.