Heat Resistance of Epoxy-modified Silicone/Al-Sm₂O₃ Composite Coatings

Epoxy-modified silicone/Al-Sm₂O₃ composite coatings with epoxy-modified silicone and Al & Sm₂O₃as adhesives and pigments were prepared through spraying method. The effect of heat treatment temperature and heat treatment time on the appearance, microstructure, near-infrared reflectivity, infrared emissivity and mechanical properties of the coating were systematically investigated. The results indicate that after heat treatment at 300 ℃ with 5 h, the appearance and microstructure of the coatings remain unchanged, and the emissivity and near-infrared reflectivity at 1.06 μm are as low as 0.607 and 64.7% respectively; hardness, adhesion strength, and impact strength are maintained at 4 H, 1 grade and 50 kg·cm respectively. After heat treatment at 250 ℃ with 100 h, the appearance and microstructure of the coatings remain unchanged, and the emissivity and near-infrared reflectivity at 1.06 μm are as low as 0.624 and 67.1% respectively; hardness, adhesion strength and impact strength are maintained at 4 H, 1 grade and 50 kg·cm respectively