Effect of Y2O3 addition on microstructure of Ni-based alloy + Y2O3/substrate laser clad

To improve hardness and corrosion resistance of aluminum substrate, using laser cladding technique, metal composite with Ni-based alloy, refining and dispersion strengthening Y2O3, particle hardening W, Cr was obtained. The microstructure and morphology, phase identification, element diffusion and composition analysis of the Ni-based alloy + Y2O3/substrate laser clad and laser clad/aluminum substrate interface were examined using scanning electron microscopy (SEM), Electron Probe Microanalyzer (EPMA), energy-dispersive spectrometer (EDS) analysis. The corrosion resistance was investigated also. The results showed, with the addition of Y2O3, more fine microstructures consisted of isometric crystal, white acicular crystal and fringe crystal; primary phases were mainly Ni3Al, NiAl, NiAl3, W, α-Al and CrxC. The corrosion rate of aluminum substrate was nearly two times more than that of laser clad metals with addition of Y2O3.