Oxidation and cracking/spallation resistance of ZrB2–SiC–TaSi2–Si coating on siliconized graphite at 1500 °C in air
Oxidation and cracking/spallation resistance of ZrB2–SiC–TaSi2–Si coating on siliconized graphite at 1500 °C in air
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DOI：
10.1016/j.ceramint.2019.11.095
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发表时间：
2020-04
影响因子：
5.2
通讯作者：
Yanqun Ren;Y. Qian;Jingjun Xu;Yan Jiang;J. Zuo;Mei-shuan Li
中科院分区：
文献类型：
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作者：
Yanqun Ren;Y. Qian;Jingjun Xu;Yan Jiang;J. Zuo;Mei-shuan Li
采用料浆刷涂和气相渗硅相结合的工艺在渗硅石墨基体上制备了ZrB 2-SiC-TaSi 2-Si涂层。研究了涂层的高温氧化行为和抗开裂性能。结果表明，在1500 °C静态空气中，氧化动力学符合抛物线规律，氧化速率常数较低，仅为0.27 mg/（cm2.h0.5）。在1500 °C至室温的20次剧烈热循环后，测得所制备涂层的裂纹面积比为3.8 × 10− 3。涂层具有良好的抗氧化和抗开裂性能，除了形成了ZrO 2骨架相和SiO2填充相外，还与其独特的层状结构有关，填充有Si的致密ZrB 2-SiC-TaSi 2主层和最外面的Si包覆顶层。同时，SiC过渡层与石墨基体及ZrB_2-SiC-TaSi_2-Si外层之间的强结合强度也是一个重要因素。
A ZrB2–SiC–TaSi2–Si coating on siliconized graphite substrate was prepared by a combination process of slurry brushing and vapor silicon infiltration. The high-temperature oxidation behavior and cracking/spallation resistance of the as-prepared coating were investigated in detail. It was revealed that the oxidation kinetics at 1500 °C in static air followed a parabolic law with a relatively low oxidation rate constant down to 0.27 mg/(cm2·h0.5). The crack area ratio of the as-prepared coating was determined as 3.8 × 10−3after severe thermal cycling from 1500 °C to room temperature for 20 times. Apart from the formation of ZrO2as skeleton phase with SiO2as infilling species, the good oxidation and cracking/spallation resistance of the coating also could be attributed to its unique duplex-layered structure, i.e., a dense ZrB2–SiC–TaSi2major layer filled with Si and an outermost Si cladding top layer. Meanwhile, the strong adhesion strength of the SiC transition layer with the graphite substrate and the outer ZrB2–SiC–TaSi2–Si layer was a vital factor as well.