The Science, Technology, and Implementation of TiAl Alloys in Commercial Aircraft Engines

Abstract

The present article will describe the science and technology of titanium aluminide (TiAl) alloys and the engineering development of TiAl for commercial aircraft engine applications. The GEnx TM engine is the first commercial aircraft engine that is flying titanium aluminide (alloy 4822) blades and it represents a major advance in propulsion efficiency, realizing a 20% reduction in fuel consumption, a 50% reduction in noise, and an 80% reduction in NOx emissions compared with prior engines in its class. The GEnx TM uses the latest materials and design processes to reduce weight, improve performance, and reduce maintenance costs. GE’s TiAl low-pressure turbine blade production status will be discussed along with the history of implementation. In 2006, GE began to explore near net shape casting as an alternative to the initial overstock conventional gravity casting plus machining approach. To date, more than 40,000 TiAl low-pressure turbine blades have been manufactured for the GEnx TM 1B (Boeing 787) and the GEnx TM 2B (Boeing 747-8) applications. The implementation of TiAl in other GE and non-GE engines will also be discussed.