Ablation behavior of ZrB2-SiC-ZrO2 ceramic composites by means of the oxyacetylene torch

Ablation behavior of ZrB2-SiC-ZrO2 ceramics with two ZrO2 contents was investigated using oxyacetylene torch. Thermogravimetric analysis demonstrated that ceramic with 10 vol% ZrO2 showed initial weight change at higher temperature than the one with 20 vol% ZrO2. After same ablation condition, lighter oxidized microstructure and lower weight loss and line gain were obtained from ceramic with 10 vol% ZrO2. Ablation mechanism revealed that excessive ZrO2 would supply much path to the inward transport of oxygen, which led to the dissatisfactory resistance to oxidation and ablation for the ceramic with 20 vol% ZrO2.