Bonding gamma-TiAl alloys using Ti/Al nanolayers doped with Ag

• Type: Article in International Conference Proceedings Book
• Date: 2008

Authors

Duarte, LI (Author) Other; Filomena Viana (Author) FEUP; Vieira, MF (Author) FEUP; Ramos, AS (Author) Other; Vieira, MT (Author) Other; Klotz, UE (Author) Other

Conference proceedings International

Title: ADVANCED MATERIALS FORUM IV

Pages: 488-491

13th Conference of the Sociedade-Portuguesa-de-Materiais/4th International Materials Symposium

Oporto, PORTUGAL, APR 01-04, 2007

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ISI Web of Knowledge - 3 Citations

Scopus - 4 Citations

Other information

Authenticus ID: P-007-PKW

DOI: 10.4028/www.scientific.net/msf.587-588.488

Abstract (EN): Successful solid state bonding of titanium aluminides requires the use of high temperature and pressure. In previous works, authors have demonstrated that the use of Ti/Al multilayer thin film as an interlayer, deposited by d.c. magnetron sputtering onto the joining surfaces, can effectively lower the bonding temperature. The enhanced diffusivity of these nanometric layers and the heat evolved by the formation of gamma-TiAl improves the joinability of titanium aluminide by solid-state diffusion bonding. In the present work, further improvement of the process was pursued by doping the interlayer with 2.8 at.% of Ag; previous studies have confirmed that silver favours the transformation Ti+Al ->gamma=TiAl. The solid-state diffusion bonding experiments were performed in vacuum by applying 50 MP a at 900 C for 1 h. The effect of the third element on the microstructure and chemical composition alone the bonding interface has been analyzed. Microstructural characterisation of the interface was performed by scanning and transmission electron microscopy. Chemical compositions were analysed by energy dispersive X-ray spectroscopy. No defects were observed at the interface and sound bonding was achieved between the interlayers and base gamma-TiAl. The bonding interface shows a fine-grained microstructure, slightly coarser than the one formed at the same temperature with the undoped Ti/Al multilayer.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 4