The comparative study on microstructure and properties of nano-CeO2 and Sm2O3 particulate reinforced nickel-based composites by laser deposition

Micron size Ni-based alloy (NBA) powders are mixed with both 1.5 wt% nano-CeO2 (n-CeO2) and nano-Sm2O3 (n-Sm2O3) powders. These mixtures are coated on low carbon steel by laser deposition. Based on the thermodynamic characteristic of rare earth oxides, evolution of microstructure and variety of phase and properties of the coatings by the addition of n-CeO2 and Sm2O3 powders to NBA have been investigated comparatively. The morphology of dendrite is transformed from bulky without n-CeO2 and Sm2O3 into fine and compact with the addition of 1.5% n-CeO2 and Sm2O3. And lamellar spacing of the eutectic of n-CeO2/NBA is smaller than that of n-Sm2O3/NBA. The microhardness, wear resistance and corrosion resistance of the coatings are greatly improved by n-CeO2 and Sm2O3 powder addition.