Effects of Annealing on the Microstructure and Wear Resistance of AlCoCrFeNiTi0.5 High-entropy Alloy Coating Prepared by Laser Cladding

Annealing behavior of AlCoCrFeNiTi0.5 high entropy alloy coatings prepared by laser cladding was investigated. The specimens were annealed at 900 °C for 5 h. The microstructure and wear resistance of the as-annealed and as-cast specimens were investigated. The XRD results indicate that the as-annealed AlCoCrFeNiTi0.5 high entropy alloy coating is composed of Al80Cr13Co7, Co3Ti, and AlFe solid solution phase. The SEM results and EDS data show that a typical spinodal decomposition structure with uniform composition is formed after annealing treatment. The average Vickers micro-hardness of the as-annealed coatings could reach 9890 MPa which is increased by about 73.5% compared with that of the as-cast coatings. The abrasion resistance testing shows that the abrasion loss of the as-annealed coatings is reduced by 92.5% and the wear width is reduced by 50% compared with the values of as-cast coatings.