Effect of nano-CeO2 on the microstructure and properties of laser clad nickel-based alloy coating

The microstructure and properties of laser clad coating are introduced after adding nano particles.Nickel-based alloy powder with different addition of nano-CeO2 is laser cladded onto Q235 steel substrate.The coating is examined to reveal the microstructure,phase composition,microhardness and wear resistance using optical microscope(OP),X-ray diffractometer(XRD),microhardness tester,block-on-ring wear tester and scanning electron microscope(SEM) respectively.The results show that fine dendrite and equiaxed dendrite are observed by adding nano-CeO2.Equiaxed dendrite across the section is obtained when the additive reaches to 1.5%(mass fraction).A new phase(Ce2Ni21B6) is found.The microhardness and wear resistance of the coating are much higher than those of the substrate,and further improved by adding nano-CeO2.But the hardness decreased when the additive amount is much high.The mechanism of these effects is also discussed.