Microstructure, mechanical property and corrosion resistance of FeCoCrNi-M high-entropy alloy coatings on 6061 aluminum alloy prepared by laser cladding

To improve the comprehensive surface performance of 6061 aluminum alloys and reduce the influence of Al dilution behavior on the coating quality, FeCoCrNi-M (M = Mn, Cu, Ti, −) high-entropy alloy coatings were prepared by a double-layer laser cladding method. The FeCoCrNi, FeCoCrNiMn and FeCoCrNiCu coatings all consisted of a single face-centered cubic (FCC) phase. The FeCoCrNiTi coating consisted of FCC, body-centered cubic (BCC), Laves and AB-type phases. The addition of Mn or Cu decreased the hardness of the FeCoCrNi coating from 209 HV to 188 or 165 HV, and increased the wear rate from 1.16 × 10−4 mm3/N·m to 1.62 × 10−4 or 3.01 × 10−4 mm3/N·m. The addition of Ti increased the hardness to 908 HV and decreased the wear rate to 2.32 × 10−5 mm3/N·m. The current density of the FeCoCrNi coating (6.37 × 10−8 A/cm2) in 3.5 wt% NaCl solution increased with Cu or Mn addition (2.15 × 10−7 or 3.26 × 10−7 A/cm2), but decreased with Ti addition (1.15 × 10−8 A/cm2). FeCoCrNi-M coatings significantly enhanced the hardness, corrosion resistance and wear resistance of the aluminum alloy substrate.