Microstructure and tribological behaviors of FeCoCrNiMoSix high-entropy alloy coatings prepared by laser cladding

FeCoCrNiMo high-entropy alloy (HEA) has attracted great interests due to its excellent corrosion resistance, but it suffers relatively low hardness and poor tribological performance. In this work, a systematic study on microstructural evolution and tribological behavior of equiatomic FeCoCrNiMoSix (x = 0.5, 1.0, 1.5) HEA coatings prepared by laser cladding (LC) on Q235 steel substrates is reported. Confirmed by X-ray diffraction analysis (XRD) and energy dispersive spectrometry (EDS) results, these coatings mainly consist of Fe-rich FCC and FeMoSi phases. The increase of Si content leads to greater lattice distortion and promotes the formation of Si-rich intermetallics, which can significantly improve the hardness and the wear resistance of the FeCoCrNiMoSix coatings. The best wear resistance is achieved in FeCoCrNiMoSi1.0 coating, which the wear mechanism is a combined abrasive and adhesive wear.