Effect of ZrB₂ and SiC distributions on the ablation of modified carbon/carbon composites

To understand the effect of introduced phases' distribution on the ablation of carbon/carbon (C/C) composites, C/C-ZrB2-SiC composites containing isolated (SZ-1) and coupled (SZ-2) ZrB_2-SiC particles were prepared via controllable precursor infiltrations and pyrolysis, respectively. Ablation under oxyacetylene torch at both Z and XY directions showed that SZ-1 had better ablation resistance than SZ-2, while the surface temperature rose up to about 2400 °C. The ablated surface morphologies showed that a relative integrate layer of ablation products was formed on SZ-1, whereas the layer on SZ-2 was defective. It was believed that the dissimilar distributions of ZrB_2- SiC particles in composites resulted in distinct structures of ablation products on the surfaces and consequently their different ablation behavior.