Quo vadis gamma titanium aluminide

A perspective is offered on the implementation of gamma -TiAl for various components in aircraft engines, aerospace vehicles and automotive engines. The key to acceptance within the next 5 years is a manufacturing route that balances cost and benefit. The two basic routes are (1) near net-shape casting, which is an economical way to produce a component for evaluation, and (2) a wrought route for specific components utilizing ingot extrusion. Cast LP (low-pressure) turbine blades and static structural components for aircraft engines are reviewed with attention directed to automotive cast turbocharger wheels and exhaust valves as promising market possibilities. Wrought processing via ingot extrusion, which provides shape and structure for isothermal forging of compressor blades and LP turbine blades has emerged as the preferred manufacturing route, and shown to be successful for higher alloyed versions of TiAl. Finally, the total implementation costs and concerns are summarized along with the factors governing the selection of a rotating component in an aircraft engine. (C) 2001 Elsevier Science Ltd. All rights reserved.