In-situ synthesis of COp/Cu composite coating by laser cladding

Uniform Cop/Cu composite coatings were fabricated by laser cladding and rapid solidification technique, and the influences of processing parameters on microstructure were investigated by scanning electron microscope and energy dispersive spectroscopy. The results showed that high undercooling in the laser melting pool was helpful to the liquid phase separation of Cu-Co alloy. Cop/Cu composite coating with smooth surface can be successfully in situ synthesized when the processing conditions were well controlled. The as-solidified microstructures were characterized by a distribution of small spherical Co-rich particles homogeneously dispersed in the Cu-rich matrix. Cop/Cu coating was consisted of γ-Co and Cu-rich solution. With the decreasing of laser heat input, the diameters of spherical particles in coating decreased. The microstructural evolution and refining mechanism of the Cop/Cu coatings were also discussed.