Oxidation behavior and kinetics of ZrB2 containing SiC chopped fibers
Oxidation behavior and kinetics of ZrB2 containing SiC chopped fibers
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DOI：
10.1016/j.jeurceramsoc.2015.07.024
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发表时间：
2015-12
影响因子：
5.7
通讯作者：
L. Silvestroni;E. Landi;K. Bejtka;A. Chiodoni;D. Sciti
中科院分区：
文献类型：
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作者：
L. Silvestroni;E. Landi;K. Bejtka;A. Chiodoni;D. Sciti
用热重分析仪在1200 - 1500°C的温度下对SiC短纤维增韧的zrb2进行了10小时的氧化测试，并在自下而上的加载炉中在1650°C的温度下进行了5-30分钟的氧化测试。采用扫描电镜和透射电镜对其微观结构进行了研究。氧化动力学经过一个瞬态阶段后，遵循线性行为，表明在1400℃以上，外层氧化层不具有保护作用。纤维在1500°C以上氧化，形成硅玻璃和富碳相。在不同的温度范围内，提出了碳化硅纤维氧化的机理和各种鳞片的形成。并与含SiC的zrb2在颗粒、晶须和上一代纤维的氧化形式进行了比较。
The oxidation of ZrB2toughened with SiC short fibers has been evaluated in a thermo-gravimetric analyzer from 1200 to 1500 °C for 10 h and in a bottom-up loading furnace up to 1650 °C for 5–30 min. The microstructure has been investigated by SEM and TEM. The oxidation kinetics, after a transient stage, follows a linear behavior, indicating that the outer oxide layer is not protective above 1400 °C. Fibers notably oxidize above 1500 °C with formation of silica glass and a carbon-rich phase. Mechanisms of SiC fiber oxidation and formation of the various scales are proposed for the various temperature ranges. Comparisons with the oxidation of ZrB2containing SiC in form of particles, whiskers and previous generation fibers are also discussed.