Study on Low Density and Heat-resistant Ablative Coating

Low bulk density expanding vermiculite is prepared, and the surface modification of hollow Al2O3-SiO2 microspheres and the composition of the low density ablative coating are studied. Organic silicon epoxy resin and phenolic aldehyde resin are applied as film forming matters to get a series of ablative coating having a density of 0.4-0.6 g/cm3. The performance of the low density ablative coating is evaluated by mechanical, thermodynamic and oxygen acetylene ablation tests, and the results are as follows, adhesion is in the range of 2.97-4.63 MPa, conductivity is no more than 0. 1 kcal/(m·h· °C), line ablation rate is no more than 0.30 mm/s, mass ablation rate is in the range of 0.11-0.18 mm/s.