Reaction diffusion in continuous SiC fiber reinforced Ti matrix composite

• Published in: Transactions of Nonferrous Metals Society of China 2007, Vol.17 (1), p.27-34
• Main Author: 吕祥鸿 杨延清 黄斌 罗贤 刘玉成
• Format: Article
• Language: English
• Subjects: activation energy; interfacial phases; reaction diffusion; SiC/TAIcomposite; 机械性能; 活化能; 碳化硅纤维
• ISSN: 1003-6326
• DOI: 10.1016/S1003-6326(07)60043-0

SiC continuous fiber-reinforced pure Ti（TA1） matrix composites were fabricated by a vacuum hot pressing（VHP） method and then heat-treated in vacuum under different conditions. The interracial reaction and the formation of interracial phases were studied by using SEM, EDS and XRD. The results show that there exists reaction diffusion at the interface of SiC fibers and Ti matrix, and the concentration fluctuation of reaction elements such as C, Ti and Si appears in interracial reaction layer. The interracial reaction products are identified as Ti3SiC2, TiCx and Ti5Si3Cx. At the beginning of interracial reaction, the interracial reaction products are TiCx and TisSi3Cx. Along with the interracial reaction diffusion, Ti3SiC2 and Ti5Si3Cx single-phase zones come forth in turn adjacent to SiC fibers, and the TiC＋Ti5Si3Cx double-phase zone appears adjacent to Ti matrix, which forms discontinuous concentric rings by turns around the fibers. The formed interracial phases are to be Ti3SiC2, TisSi3Cx and TiCx＋TisSi3Cx from SiC fiber to Ti matrix. The interfacial reaction layer growth is controlled by diffusion and follows a role of parabolic rate, and the activation energy （Q^k） and （k0） of SiC/TA1 are 252.163 kJ/mol and 7.34×10^-3 m/s^1/2, respectively.