Improved thermal expansion performance of Aluminum/polysiloxane/glass coatings with low infrared emissivity by zinc powder

Abstract

Thermal expansion performance of Aluminum/polysiloxane/glass coatings with low infrared emissivity was improved by adding zinc powder. The influences of zinc powder on phase structure, composition, surface microstructure, thermal expansion, adhesion and infrared radiation of Aluminum/polysiloxane/glass coating was systematically studied. The thermal mechanical analysis indicated that thermal expansion coefficient can be adjusted by adding zinc powder in the coating. The tensile strength test results show that the matching of the thermal expansion could improve the adhesion strength of the coatings. As a result, compared with the coating without zinc powder, the adhesion strength was enhanced by 2.0 ± 0.4 MPa when the heat treatment temperature at 450 and 500 °C, and increased by 3.0 ± 0.4 MPa at 550 °C. Simultaneously, average infrared emissivity value of the coating with good thermal stability was about 0.20 in the 3–5 μm wavebands, and approximately 0.34 within 8–14 μm after heated at 550 °C. These results indicated that the good thermal expansion performance and low infrared emissivity coatings were obtained by adding zinc powder.