Oxidation behavior of reactively synthesized porous Ti3(Si,Al)C2 compound at 800 °C in ambient air
Oxidation behavior of reactively synthesized porous Ti3(Si,Al)C2 compound at 800 °C in ambient air
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DOI：
10.1016/j.ceramint.2019.05.051
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发表时间：
2019-08
影响因子：
5.2
通讯作者：
Zhonghe Wang;Yao Jiang;Yuehui He
中科院分区：
文献类型：
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作者：
Zhonghe Wang;Yao Jiang;Yuehui He
多孔MAX复合材料结合了金属和陶瓷的优点，在恶劣环境下具有很大的过滤应用前景。采用元素粉末反应合成法制备了多孔Ti 3（Si，Al）C2，并研究了其在800 °C下循环氧化100 h后的抗氧化性能。合成的Ti 3（Si，Al）C2的MAX相纯度大于99vol%，最大孔径、开孔率和透气率分别为5.3 μm、42.9%和16.27 m3·m−2·kPa−1·h−1。多孔Ti 3（Si，Al）C2的氧化动力学可分为两个阶段，在最初的10 h内为线性规律，在随后的稳定期为抛物线规律，其氧化速率常数分别为1.37 × 10− 2 h − 1和4.76 × 10− 4 h −1.最终氧化层由金红石型TiO 2和Al 3 Ti 5 O2相组成。在稳定阶段，最大孔径和开孔率几乎保持不变，线性下降率分别为4.32 × 10 - 3μm·h-1和5.58 × 10 - 2%·h-1，分别为初始阶段的2.1%和3.6%。在最后40 h的氧化过程中，渗透率下降了2.8%，显示出较高的稳定性。高温氧化处理后的多孔Ti 3（Si，Al）C2保持了较高且稳定的渗透率，过滤精度提高了96.3%，改善了过滤性能。
Porous MAX compound combines the advantages of metals and ceramics, and has great filtration application prospects in harsh environments. In this work, porous Ti3(Si,Al)C2was prepared by reaction synthesis of elemental powders, and its cyclic oxidation resistance at 800 °C for 100 h was studied. The synthesized Ti3(Si,Al)C2has the MAX phase purity above 99 vol% with the maximum aperture, open porosity and permeability of 5.3 μm, 42.9% and 16.27 m3·m−2·kPa−1·h−1, respectively. The oxidation kinetics of porous Ti3(Si,Al)C2is divided into two stages, which includes the linear law for the initial period within the first 10 h and the parabolic law for the subsequent stable period with their oxidation rate constants of 1.37 × 10−2h−1and 4.76 × 10−4h−1, respectively. The final oxide layer is composed of rutile TiO2and Al3Ti5O2phases. In the stable stage, the maximum aperture and open porosity remain nearly constant with slight linear reduction rates of 4.32 × 10−3μm·h−1and 5.58 × 10−2%·h−1, which are 2.1% and 3.6% of those in the initial stage, respectively. In the last oxidation procedure of 40 h, the permeability decreases by 2.8%, showing a high stability. The high-temperature oxidation process for porous Ti3(Si,Al)C2maintains a high and stable permeability and enhances the filtration accuracy by 96.3%, which improves the filtration performance.