TiAl alloys in commercial aircraft engines
The present article will describe aspects of the science and technology of titanium aluminide (TiAl) alloy system and summarise the low and high temperature mechanical and environmental properties exhibited by different alloy generations. In terms of processing developments, conventional gravity casting and near net shape casting would be discussed in detail. Also newer and non conventional forging and additive manufacturing routes would be briefly highlighted. Extensive investigations of TiAl alloys have enabled their commercial implementation in aerospace and automotive industries. The GEnx(tm) engine is the first commercial aircraft engine that used TiAl (alloy 48 2 2) for their low pressure turbine blades. Among non GE engines, recently, new b stabilised TiAl alloy (TNM) is being used to manufacture LPT blades for PW1100G(tm) engines. TiAl materials and design processes can reduce engine weight and improve engine performance.