1. Designed microstructure of the thermal insulation coating(a) Cross section; (b) Bonding layer surface; (c) Barrier layer surface; (d) Reflective layer surface

2. Thickness optimization of the designed functional layers(a) Time required for coating to fall off at 160 and 190 ℃; (b) Reflectivity of coatings with different thicknesses of reflective layers; (c) Temperature difference change curves for coatings with different thicknesses of the barrier layer

3. Weight loss curves of the thermal insulation coatings at different temperatures

4. Macroscopic morphology changes of the coatings when heated at 160 ℃ for different time(a) 0 h; (b) 1 h; (c) 2 h; (d) 4 h

5. SEM morphology changes of coatings heated at 160 ℃ for 4 h(a) Coating cross-section; (b) Reflective layer surface

6. TEM iamges of nonmetric TiO₂ in coatings (a) before and (b) after being heated and corresponding EDS of (c) point 1, (d) point 2, (e) point 3, and (f) point 4 in (a) and (b)