Gamma titanium aluminide alloys—an assessment within the competition of aerospace structural materials

In the late 1970s and early 1980s, intermetallic phases emerged from being alloys of laboratory curiosity, or precipitate structures to be avoided or controlled in many ‘real metals’, to being widely investigated alloys, especially as prospective structural materials. After nearly two decades of sustained world-wide research, selected materials are emerging with a balance of properties which improves engineered systems, while others are introducing compelling research questions and prospects for significantly improved materials. This manuscript briefly examines selected intermetallic alloys and how they compete with other structural materials. The examination focuses on gamma titanium–aluminide alloys, from the perspective of their balance of engineering properties, state of maturity, and prospects for impacting industrial needs. A variety of engineering and business challenges remain to be solved, some of which are discussed.