Fabrication and performances of preceramic polymer-based high-temperature High emissivity coating

High emissivity coatings on nickel-based superalloy, with good infrared radiating ability and good high temperature resistance, were prepared at room temperature, using preceramic polymer cured at room-temperature as coating former and CeO₂ and B₄C as passive high emissivity fillers. The influences of high temperature and wind channel test on the microstructure and thermal performance of the high emissivity coating were investigated in detail. The high emissivity coating has good thermal stability and no cracking and flaking after heating at 1100 K and the wind tunnel test. The emissivity of the coating reached 0.85?0.92 between room temperature and 1100 K. The high emissivity coating on the nickel-based alloy can make the back temperature of the nickel-based alloy decrease from 686 to 646 ℃.