Study Of Preparation And Properties For Infrared Radiant Coatings Of High Emissivity

Infrared radiant base materials were prepared by calcining under reductive and oxidative atmospheres, respectively, and rapid cooling and slow cooling, according to the TG-DSC results, from low cost of transition metal oxides Fe2O3 and MnO2 as main raw materials, and small quantity of CuO and CoO as additives. Infrared radiant coatings of good thermal shock resistance were fabricated by doping certain amount of cordierite and adhesive into the base materials. The material formulation was optimized through the orthogonal experiments. The phases,microstructures,the chemical valence of the inner ions and emissivity of the the infrared radiant coatings were characterized through XRD, SEM, FT-IR, XPS and emissivity examination etc. The main results are follows:1. Fe-Mn-Cu-Co system was doped with cordierite and adhesive, the infrared radiant coatings with high thermal shock resistance and emissivity were obtained, the emissivity was all above 0.85 in the whole infrared bands, especially in the near infrared bands(2.5~ 5μm) the spectral emissivity closed to the blackbody.2. Fe2O4 based the radiant coatings were mainly composed of the spinel phase (CuFe)Fe2O4, and MnO2 based the radiant coatings were mainly composed of the anti-spinel phase CoMn2O4.3. The infrared radiant emissivity increased with increasing the MnO2 content, when the MnO2 content was about 60wt%, the emissivity reached the maximum, and then began to decrease with increasing the MnO2 content.4. Fe, Mn, Cu and Co ions showed different chemical valences in the infrared radiant base materials calcined under reductive atmosphere and rapid cooling conditions, and the reductive atmosphere and rapid cooling were benefit to improve the emissivity.5. Dopings of cordierite and adhesives did not significantly influence the emissivity, but greatly improved the thermal shock resistance of coatings.6. The adhesive doping amount significantly influnced the thermal shock resistance of coatings, but the adhesive formulation had not significant effect on the thermal shock resistance.