Effects of Ti content on the microstructure and properties of AlCoCrFeNiTix high-entropy alloys prepared by laser cladding

The work adopted the method of combining calculations and experiments to explore the mechanism of the influence of Ti content on the microstructure and properties of AlCoCrFeNiTix high-entropy alloy coatings. The change mechanism of the Ti molar ratio was analyzed concerning the phase, microstructure, and properties of the coating based on the first principles. The results showed that AlCoCrFeNiTix HEAs were BCC single-phase solid solutions. The lattice constant increased with the increased Ti molar ratio, and the density decreased as the ratio increased. The coating structure was composed of equiaxed grains, and the addition of Ti could significantly refine the grains. The theoretical structural mechanics was stable with the Ti molar ratio >= 0.8. The experimental results showed that the average microhardness of the coating increased with increased Ti content. The friction coefficient together with the wear area was reduced, while the wear resistance was enhanced. The coating-wear mechanisms changed from adhesive wear to abrasive wear. The experimental results agree with the pattern of first-principles calculations. The research results of the work can provide a theoretical reference and basis for the composition design, synthesis, and performance research of laser cladding high-entropy alloy materials.