Effect of melting current on microstructure, mechanical, and corrosion properties of wire arc additive non-equimolar FeCrNiMnCuSi high-entropy alloys

To explore the application of high-entropy alloys in the field of additive manufacturing, a non-equimolar FeCrNiMnCuSi HEAs was prepared using wire arc additive manufacturing technology. The effects of different cladding currents on the microstructure, microhardness, tensile properties, tribological properties, and corrosion resistance of the HEAs bulk were investigated. The experimental results showed that the prepared HEAs bulk was composed of FCC phases with the columnar crystals. As the cladding current increased, the average grain size of the HEA increased from 41.9 μm at 160 A to 68.5 μm at 220 A, the average hardness decreased, and the tensile strength exhibited a trend of first increasing and then decreasing. At a cladding current of 180 A, the tensile properties were optimal, with a tensile strength of 746.88 MPa and an elongation of 46.85% in the build direction, and a tensile strength of 768.53 MPa with an elongation of 38.12% in the transverse direction. As the cladding current increased, the wear rate of the HEAs initially decreased and then increased. The lowest wear rate reaching 4.36 × 10−5 mm3·N−1·m−1 was observed at a cladding current of 180 A. The wear mechanism of the 180 A HEAs was mainly adhesive wear and oxidative wear. Additionally, as the cladding current increased, the corrosion resistance of the HEAs improved. This improvement was primarily due to the higher cladding current inhibiting the segregation of Cu at the grain boundaries, thereby preventing uneven corrosion behavior.