- Titanium aluminide
Titanium aluminide, TiAl, is an
intermetallic chemical compound .It is lightweight and resistant to oxidation and heat, however it suffers from low
ductility . The density of gamma TiAl is about 4.0g/cm³. It finds use in several applications including automobiles and aircraft. The development of TiAl based alloys began about 40 years ago, however the alloys have only been used in these applications since about 2000.Titanium aluminide has three major intermetallic compounds: gamma TiAl, alpha 2-Ti3Al and TiAl3. Among the three, gamma TiAl has received the most interest and applications. Gamma TiAl has excellent mechanical properties and oxidation/corrosion resistance at elevated temperatures (over 600 degrees Celsius), which makes it a possible replacement for traditional Ni based
superalloy components in aircraftturbine engines.TiAl based alloys have a strong potential to increase the thrust-to-weight ratio in the aircraft engine. This is especially the case with the engine's low pressure turbine blades and the high pressure compressor blades. These are traditionally made up of Ni based superalloy, which is nearly twice as dense as TiAl based alloys.
General Electric has recently announced that gamma TiAl low pressure turbine blades will be used on itsGEnx engine, which powers theBoeing 787 andBoeing 747-8 aircraft. This is the first large-scale use of this material on a commercial jet engine. The TiAl LPT blades are cast byPrecision Castparts Corp. External links
* [http://gltrs.grc.nasa.gov/reports/1999/TM-1999-209071.pdf Titanium Aluminide Applications in the HighSpeed Civil Transport]
* [http://www.azom.com/details.asp?ArticleID=1548 Titanium Aluminides - Intermetallics] on azom.com.
* [http://www.flightglobal.com/Articles/2006/06/13/207148/Power+House.html Power House (GEnx TiAl LPT Blade Announcement)]
*cite journal | journal = Intermetallics | volume = 9 | issue = 12 | Pages = 997-1001 | doi = 10.1016/S0966-9795(01)00064-4 | year = 2001 | title = Quo vadis gamma titanium aluminide | author = Edward A. Loria
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