摘要
The ablation properties of two laminated composites, having both a glass ceramic matrix and different kinds of fibers (C or SiC) with the same architecture, are evaluated and compared. Ablation tests are performed using an oxyacetylene torch on samples having two different thicknesses. Mass loss and ablation depth are measured after flame exposure. The results obtained show that the decomposition of SiC fibers during thermal exposure has a significant impact on ablation behavior. Oxidation of SiC produces a liquid SiO2 film at the top of the material during ablation. This leads to an improved ablation resistance compared to the glass ceramic matrix/C composite, especially in case of successive flame exposures where the SiO2 film consumes a substantial fraction of the heat flow during its liquefaction upon re-heating.
The ablation properties of two laminated composites, having both a glass ceramic matrix and different kinds of fibers (C or SiC) with the same architecture, are evaluated and compared. Ablation tests are performed using an oxyacetylene torch on samples having two different thicknesses. Mass loss and ablation depth are measured after flame exposure. The results obtained show that the decomposition of SiC fibers during thermal exposure has a significant impact on ablation behavior. Oxidation of SiC produces a liquid SiO2 film at the top of the material during ablation. This leads to an improved ablation resistance compared to the glass ceramic matrix/C composite, especially in case of successive flame exposures where the SiO2 film consumes a substantial fraction of the heat flow during its liquefaction upon re-heating.
