Research On The YSZ System Low Infrared Emissivity Coatings In3~5μm Wavelengths With High Temperature Resistant And Thermal Shock Resistance

The infrared emissivity of aircraft thermal components generally high, the main way to solve thisproblem is on its surface coated with a layer of low emissivity coating with high temperature resistant.YSZ system powder was selected by this text for studying. It was treated by high temperature andadulteration to lower emissivity, mixed with inorganic silicate binder to make low infrared emissivitycoating with high temperature resistance; thermal barrier coatings served as in-between transitionlayer was coated on baseplate surface by plasma spraying technology, improving the mechanicalproperties of low infrared emissivity coating including thermal shock resistance property. Themechanism of the effect of crystal texture, electrical conductivity,binder on powder emissivity wasanalysed through XRD, SEM, FT-IR test tool.The obtained research results were as follows:1. In this paper,8YSZ powder was prepared by the method of citric acid and complexation, ofwhich the emissivity is0.437in room temperature and reduced to0.323in600℃in3~5μmwavelengths.2. Through comparative analysis of the emissivity in3~5μm wavelengths of three different YSZpowders after different heat-treatment,it can be learned that heat treatment is helpful to improve thepowder crystallinity and regularity, reduce the infrared radiation of grain boundary of YSZ powdersand lower the infrared emissivity. The resistor of three YSZ powers at different were measured, andthe results suggest that good conductivity is beneficial to lower emissivity.3. The conductivity of8YSZ powders was improved and increased when they were doped viadifferent elements and concentration, so the emissivity was reduced.4. Selecting the [Ce0.9Ca0.1O1.9]0.15[(MoO3)0.05(8YSZ)0.95]0.85powder with the lowest emissivityas a pigment and the inorganic silicate as a binder, the emissivity of the coating was0.277afterhigh-temperature cured at600℃. Also, the influence factors of the percentage of pigment, the curingtemperature on the emissivity in3~5μm wavelengths of the coating were discussed.5. Through taking the thermal barrier coating as in-between transition layer, the thermal shockresistance of high temperature resistant and low emissivity coating was enhanced obviously, of whichthe times reached to30times at600℃and26times at800℃. And the mechanism of thermalshock resistance of coatings were analyzed.6. The integrated performances of low infrared emissivity coatings with high temperature resistance and thermal shock resistance were preliminary tested.