Ablation Mechanism of Carbon/Carbon Composites Modified by HfC–SiC in Two Conditions Under Oxyacetylene Torch
来源期刊：JOURNAL OF MATERIALS SCIENCE TECHNOLOG2017年第1期
论文作者：Ke-Zhi Li Tao Duan Jia-Ping Zhang Ning-Kun Liu Mao-Yan Zhang
文章页码：71 - 78
摘 要：C/C–HfC–SiC composites prepared by precursor infiltration and pyrolysis process were ablated by oxyacetylene torch under two different flame conditions.The ablation performance of the composites was investigated in the heat flux of 2.38 MW/m2（HF-L） and 4.18 MW/m2（HF-H） for 60 s.The mechanical denudation in 4.18 MW/m2（HF-H） was higher than that in 2.38 MW/m2（HF-L）,while the results indicated that the composites had a similar and good ablation property under two different flame conditions.C/C–HfC–SiC composites can adapt the heat flux from 2.38 MW/m2 to 4.18 MW/m2.The HfO2 was not melted completely in the heat flux of 2.38 MW/m2（HF-L）.So,both HfO2 and SiO2 layers acted as an effective barrier to the transfer of heat and oxidative gases into the underlying carbon substrate.SiO2 was severely consumed in 4.18 MW/m2（HF-H）,where the HfO2 molten layer played a more important role in protecting the inner composite.
Ke-Zhi Li，Tao Duan，Jia-Ping Zhang，Ning-Kun Liu，Mao-Yan Zhang
State Key Laboratory of Solidification Processing,Carbon/Carbon Composites Research Center,Northwestern Polytechnical University
摘 要：C/C–HfC–SiC composites prepared by precursor infiltration and pyrolysis process were ablated by oxyacetylene torch under two different flame conditions.The ablation performance of the composites was investigated in the heat flux of 2.38 MW/m2（HF-L） and 4.18 MW/m2（HF-H） for 60 s.The mechanical denudation in 4.18 MW/m2（HF-H） was higher than that in 2.38 MW/m2（HF-L）,while the results indicated that the composites had a similar and good ablation property under two different flame conditions.C/C–HfC–SiC composites can adapt the heat flux from 2.38 MW/m2 to 4.18 MW/m2.The HfO2 was not melted completely in the heat flux of 2.38 MW/m2（HF-L）.So,both HfO2 and SiO2 layers acted as an effective barrier to the transfer of heat and oxidative gases into the underlying carbon substrate.SiO2 was severely consumed in 4.18 MW/m2（HF-H）,where the HfO2 molten layer played a more important role in protecting the inner composite.
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