Characteristics of Ni-based coating layer formed by laser and plasma cladding processes

The clad layers of Ni-based alloy were deposited on the SUS316L stainless plates by CO2 laser and plasma cladding processes. The smooth clad bead was obtained by CO2 laser cladding process. The phases of clad layer were investigated by an optical microscope, scanning electron microscopy (SEM), X-ray diffractometer (XRD), electron probe microanalysis (EPMA) and energy-dispersive spectrometer (EDS). The microstructures of clad layers belonged to a hypereutectic structure. Primary phases consist of boride CrB and carbide Cr7C3. The eutectic structure consists of Ni + CrB or Ni + Cr7C3. Compared with the plasma cladding, the fine microstructures, low dilutions, high Vickers hardness and excellent wear resistance were obtained by CO2 laser cladding. All that show the laser cladding process has a higher efficiency and good cladding quality.