Preparation and frictional wear property of AlCrNiFeTi high-entropy alloy coatings by electric spark deposition

AlCrNiFeTi high-entropy alloy (HEA) with a diameter of 7 mm was prepared as electrode by vacuum arc melting method, and AlCrNiFeTi high-entropy alloy coating was successfully prepared on the surface of 304 stainless steel by using electric spark deposition technology. The microstructure and friction and wear properties of the coatings were studied by XRD, OM, EDS, SEM, microhardness tester and friction and wear tester. The results show that both the AlCrNiFeTi electrode and the coating are dominated by BCC1 and BCC2 simple solid solutions, and the microstructure of the electrode is typical of dendrites. The coating is formed by stacking and spreading of deposition points, and the surface is uniform and dense as orange peel, convex and concave, unfolding for sputtering pattern, and there is no macroscopic defects in the coating cross-section structure, and the thickness is about 59.67 μm.The maximal microhardness of AlCrNiFeTi coating is 587.3HV0.2, which is about 2.45 times higher than that of the base material. As the load increases, the wear mechanism of the coating changes from oxidized wear and slight abrasive wear to abrasive and adhesive wear. When the friction load is 5 N, the wear rate is 1.213×10-3 mm3/(N·m), and the friction coefficient is only 0.446. The wear rate of the coating decreases by about 28.3% compared with that of the substrate.