Ablative property of laminated ZrB2–SiC ceramics under oxyacetylene torch

Two kinds of laminated ZrB2–SiC ceramics were successfully fabricated by aqueous tape casting, laminating and hot-pressing. The first one was alternately composed of ZrB2+36 vol% SiC layers and ZrB2+20 vol% SiC layers with sintering aid of 5 vol% B4C. The second one was achieved by inserting an aquadag interlayer between two different ZrB2–SiC layers. The ablation experiments were carried out on an oxyacetylene torch flame with a temperature of about 3000 °C. Both ceramics exhibited zero ablation in the macroscopic level after ablation for 20 s, showing outstanding ablation resistance. However, ablation oxidation layer of the second ceramic was thinner than that of the first one microscopically, which was mainly attributed to full densification of the surface ablation layer. The aquadag layer promoted sintering of laminated ZrB2–SiC ceramics at elevated temperatures.