Effect of process parameters on the microstructure and properties of laser-clad FeNiCoCrTi_0.5 high-entropy alloy coating

FeNiCoCrTi_0.5 coatings with different process parameters were fabricated by laser cladding. The macro-morphology, phase, microstructure, hardness, and wear resistance of each coating were studied. The smoothness and dilution rate of the FeNiCoCrTi_0.5 coating generally increased with the increase of specific energy (E_s), which is the laser irradiation energy received by a unit area. FeNiCoCrTi_0.5 coatings at different parameters had bcc, fcc, and Ti-rich phases as well as equiaxed, dendritic, and columnar structures. When E_s increased, the size of each structure increased and the distribution area of the columnar and dendritic structures changed. The prepared FeNiCoCrTi_0.5 coating with the E_s of 72.22 J·mm^–2 had the highest hardness and the best wear resistance, the highest hardness of the coating reached HV 498.37, which is twice the substrate hardness. The average hardness of the FeNiCoCrTi_0.5 coating with the E_s of 72.22 J·mm^–2 was 15.8% higher than the lowest average hardness of the coating with the E_s of 108.33 J·mm^–2. The worn surface morphologies indicate that the FeNiCoCrTi_0.5 coatings exhibited abrasive wear.