Substitution behavior of Si atoms in the Ti2AlC ceramics
Substitution behavior of Si atoms in the Ti2AlC ceramics
复制标题
Ti2AlC陶瓷中Si原子的取代行为
DOI：
10.1016/j.actamat.2017.11.002
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发表时间：
2018-02-01
期刊：
影响因子：
9.4
通讯作者：
Jankowiak, Aurelie
中科院分区：
文献类型：
--
作者：
Lu, Chengjie;Piven, Kseniia;Jankowiak, Aurelie
扫描电镜分析表明，在AlSi共晶钎料钎焊Ti 2AlC接头中，Si原子取代了Ti 2AlC陶瓷中的Si原子，并在相互作用区形成了Ti-2（Al，Si）C固溶体。然后，使用FIB/TEM技术进行详细的表征。STEM结果表明，改性后的Ti 2AlC陶瓷晶格常数明显降低，相应区域Si元素的存在得到了进一步证实。用从头计算方法研究了Ti-2（Al，Si）C固溶体的形成和分解机理。结果表明，不同Si含量的Ti-2（Al 1-x，Si-x）C结构在振动方面都是稳定的。然而，由于竞争相的吉布斯自由能较低，具有高Si含量的结构将分解。最后，采用SPS方法成功地合成了Ti-2（Al-0.9，Si-0.1）C块体材料。(C)2017 Acta Materialia Inc.由爱思唯尔有限公司出版。保留所有权利。
The substitution of Si atoms in the Ti2AlC ceramics has been observed in the Ti2AlC brazing joints using AlSi eutectic filler alloy, contributing to the formation of Ti-2(Al, Si)C solid solution in the interaction area according to the SEM analysis. Afterwards, a detailed characterization was performed using FIB/TEM technique. A remarkable decrease in the lattice constants has been observed in the modified Ti2AlC ceramics, and the presence of Si element in the corresponding area has been further proved by STEM. The formation and decomposition mechanisms of the Ti-2(Al, Si)C solid solution have been studied via ab initio calculations. The results suggest that all the Ti-2(Al1-x, Si-x)C structures with different Si contents are stable in the vibration aspect. However, due to the lower Gibbs energy of the competing phases, the structures with high Si content would decompose. Finally, the bulk Ti-2(Al-0.9, Si-0.1)C has been successfully synthesized using SPS method. (C) 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.