Microstructure and oxidation resistance of nanometer SiC particles reinforced NiCoCrAlY coatings

To study the effect of nanometer SiC particles(nano-SiCp) on microstructure and oxidation resistance of NiCoCrAlY coating,four kinds of NiCoCrAlY coatings with different contents of nano-SiCp were prepared on the surface of a Ni-based superalloy using laser cladding technology,and their microstructure and isothermal oxidation behaviors at 1050 °C were investigated.The influencing mechanisms of nano-SiCp were primarily discussed.The results show that the microstructure and oxidation resistance of the coatings with nano-SiCp were incoordinately improved compared with those of the coating without nanometer particles,in which the coating with 1.0 %(mass fraction) nano-SiCp displays the best performance.With the addition of nano-SiCp,not only the crystal habit of the bonding interface between coating and substrate was improved,but also the microstructure of cladding layer was refined.The refinement of cladding layer microstructure plays a very positive role in improving the oxidation resistance of the NiCoCrAlY coatings.