Formation mechanisms of Ti 2 AlC MAX phase on SiC-4H using magnetron sputtering and post-annealing
Formation mechanisms of Ti 2 AlC MAX phase on SiC-4H using magnetron sputtering and post-annealing
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DOI：
10.1016/j.matdes.2018.02.046
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发表时间：
2018-04
影响因子：
8.4
通讯作者：
J. Nicolaï;C. Furgeaud;B. W. Fonrose;C. Bail;M. Beaufort
中科院分区：
文献类型：
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作者：
J. Nicolaï;C. Furgeaud;B. W. Fonrose;C. Bail;M. Beaufort
在目前的工作中，我们专注于在Ti 2AlC MAX相薄膜形成的机制。采用磁控溅射法在SiC-4 H [0001]衬底上制备了TiAl 2薄膜。将样品在不同温度（700-800 °C）下退火不同时间，并通过XRD和TEM分析。外延Ti 2AlC相的形成如下：[0001]MAX//[0001] SiC和（11 - 20）MAX//（11- 20）SiC，这与热力学考虑很好地一致。TiC结构的存在下，在界面处表明，这种结构的形成是必要的，以获得Ti 2AlC。此外，由于TiC形成过程中Al和Si分别从TiAl 2和SiC中相互扩散，突出了液态AlSi合金的形成。最后，我们假设，在冷却过程中，AlSi合金分离和Al扩散到TiAl 2层的表面，导致富Al层的形成。剩余的Si与TiAl 2中的Ti反应形成Ti 5Si 3层，其外延关系为：[0001] Ti 2AlC//[0001] Ti 5Si 3和（11-20）Ti 2AlC//（3 - 210）Ti 5Si 3。这些机制导致四个不同层的堆叠。在700至800 °C之间，形成机制的性质不依赖于时间。然而，反应的动力学是温度和时间依赖性的。
In the present work we focus on the mechanisms involved in Ti2AlC MAX phase thin-film formation. The TiAl2thin-film was deposited by magnetron sputtering on a SiC-4H [0001] substrate. Samples were annealed at various temperatures (700–800 °C) for various times and analysed by XRD and TEM. The epitaxial Ti2AlC phase was formed as follows: [0001]MAX//[0001]SiCand (11−20)MAX//(11–20)SiCwhich is in a good agreement with thermodynamic considerations. The presence of TiC structures at the interface indicates that the formation of this structure is necessary to obtain Ti2AlC. Moreover, the formation of a liquid AlSi alloy was highlighted due to the interdiffusion of Al and Si respectively from TiAl2and SiC during TiC formation. Finally, we assume that, during the cooling, the AlSi alloy separates and Al diffuses to the surface of the TiAl2layer leading to the formation of an Al-rich layer. The remaining Si reacts with Ti from TiAl2to form a Ti5Si3layer following this epitaxial relation: [0001]Ti2AlC//[0001]Ti5Si3and (11–20)Ti2AlC//(3−210)Ti5Si3. These mechanisms lead to the stacking of four different layers. Between 700 and 800 °C, the nature of the formation mechanism is not time-dependent. However, the kinetics of the reactions are both temperature and time dependent.