Effects of PyC shell thickness on the microstructure, ablation resistance of SiCnws/PyC-C/C-ZrC-SiC composites
Effects of PyC shell thickness on the microstructure, ablation resistance of SiCnws/PyC-C/C-ZrC-SiC composites
复制标题
PyC壳层厚度对SiCnws/PyC-C/C-ZrC-SiC复合材料微观结构和耐烧蚀性能的影响
DOI：
10.1016/j.jmst.2020.08.047
复制
发表时间：
2021-04-30
影响因子：
10.9
通讯作者：
Lu, Jinhua
中科院分区：
文献类型：
--
作者：
He, Qinchuan;Li, Hejun;Lu, Jinhua
采用CLVD工艺制备了SiC纳米线/热解碳（SiCnws/PyC）核壳结构增韧C/C-ZrC-SiC复合材料，研究了PyC壳层厚度对复合材料微观结构和耐烧蚀性能的影响。结果表明，SiCnws/PyC核壳结构呈线形，随着PyC厚度的增加，复合材料变得致密。当PyC壳层厚度从0 μ m增加到2.4 μ m时，复合材料的密度和热导率逐渐提高，但热膨胀系数（CTE）先减小后增大。烧蚀90 s后，烧蚀率随热解碳厚度从0增加到1.4 μ m而持续下降，但当热解碳厚度增加到2.4 μ m时，烧蚀率逐渐上升。特别是当PyC壳层厚度为1.4 μ m时，复合材料的线烧蚀率和质量烧蚀率分别比无PyC壳层的复合材料降低了71.25%和63.01%。结果表明，合适的热解碳厚度可以改善材料的热膨胀系数失配，促进完整氧化层的形成，提高材料的热导率，降低热腐蚀，增强材料的机械烧蚀抑制能力，从而显著提高材料的抗烧蚀性能。(C)2021由Elsevier Ltd代表Journal of Materials Science & Technology编辑部出版。
SiC nanowires/pyrocarbon (SiCnws/PyC) core-shell structure toughened C/C-ZrC-SiC composites were fabricated by CLVD process, and the influences of PyC shell thickness on the microstructure and ablation resistance of the composites were researched. The results presented that SiCnws/PyC core-shell structure had a linear shape, and the composites became dense with the increasing PyC thickness. When the thickness of PyC shell increased from 0 to 2.4 mu m, the density and thermal conductivity of the composites was improved gradually, but the coefficient of thermal expansion (CTE) decreased firstly and then increased. After the ablation test for 90 s, the ablation rates of the composites decreased continuously as the PyC thickness increased from 0 to 1.4 mu m, but increased when the PyC thickness was up to 2.4 mu m. Especially when the PyC thickness was 1.4 mu m, the linear and mass ablation rates of the composites were 71.25 % and 63.01 % lower than those of the composites without PyC shell. The reasons behind the remarkable improvement of anti-ablation property were that the proper PyC thickness could alleviate the CTE mismatch to promote the formation of complete oxide coating, improve the thermal conductivity to reduce heat corrosion and enhance the capability to limit the mechanical erosion. (C) 2021 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.