ISSN:
1662-9752
Source:
Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Successful solid state bonding of titanium aluminides requires the use of hightemperature and pressure. In previous works, authors have demonstrated that the use of Ti/Almultilayer thin film as an interlayer, deposited by d.c. magnetron sputtering onto the joiningsurfaces, can effectively lower the bonding temperature. The enhanced diffusivity of thesenanometric layers and the heat evolved by the formation of γ-TiAl improves the joinability oftitanium aluminide by solid-state diffusion bonding. In the present work, further improvement of theprocess was pursued by doping the interlayer with 2.8 at.% of Ag; previous studies have confirmedthat silver favours the transformation Ti+Al→γ-TiAl. The solid-state diffusion bonding experimentswere performed in vacuum by applying 50 MPa at 900ºC for 1 h. The effect of the third element onthe microstructure and chemical composition along the bonding interface has been analyzed.Microstructural characterisation of the interface was performed by scanning and transmissionelectron microscopy. Chemical compositions were analysed by energy dispersive X-rayspectroscopy. No defects were observed at the interface and sound bonding was achieved betweenthe interlayers and base γ-TiAl. The bonding interface shows a fine-grained microstructure, slightlycoarser than the one formed at the same temperature with the undoped Ti/Al multilayer
Type of Medium:
Electronic Resource
URL:
http://www.tib-hannover.de/fulltexts/2011/0528/02/19/transtech_doi~10.4028%252Fwww.scientific.net%252FMSF.587-588.488.pdf
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