玻璃微珠和ZrB₂改性石英酚醛复合材料的耐烧蚀性能

Glass beads and ZrB₂ particles were introduced into SiO₂(f)-Phenolic (S-Ph) heat resistant composite, for the sake of enhancing its erosion resistance and ablative properties. The ablation resistance of the glass beads and ZrB₂ modified S-Ph composite were measured by oxygen-acetylene ablation test, and the effects of glass beads and ZrB₂ particles on the ablation mechanism and ablation resistance of full-density and low-density S-Ph composites were analyzed and compared. As could be seen from the results, adding appropriate amount of ZrB₂ to the low-density S-Ph composites contributed to the formation of a cladding layer on the ablative surface, which was highly protective to the carbide layer and the matrix material, and capable of reducing the linear ablation rate and the mass ablation rate. The formation of cladding layer on the surface was derived from the "pining-effect" produced by ZrO₂in melted silica, as well as the reduced surface energy of melted silica by B₂O₃. The introduction of ZrO₂ particles into the full-density S-Ph composites induced the formation of porous ZrO₂layer in the ablative process, which effectively isolate the carbide layer from the ablative environment. Nevertheless, the ZrO₂ layer did not spread by melting and weakly adhered to the carbide layer, therefore it is apt to peel off in the ablative process.