Effect of Y2O3 addition on microstructure of Ni-based alloy + Y2O3/substrate laser clad
Abstract To improve hardness and corrosion resistance of aluminum substrate, using laser cladding technique, metal composite with Ni-based alloy, refining and dispersion strengthening Y 2 O 3 , particle hardening W, Cr was obtained. The microstructure and morphology, phase identification, element diffusion and composition analysis of the Ni-based alloy + Y 2 O 3 /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 Y 2 O 3 , more fine microstructures consisted of isometric crystal, white acicular crystal and fringe crystal; primary phases were mainly Ni 3 Al, NiAl, NiAl 3 , W, α-Al and Cr x C. The corrosion rate of aluminum substrate was nearly two times more than that of laser clad metals with addition of Y 2 O 3 .