Gamma titanium aluminide is a low density, high performance alloy with the potential to replace current alloys for the production of aero engine components. The alloy is difficult to process, but investment casting has been highlighted as a possible manufacturing route. Casting of any titanium based alloy presents considerable problems, not least of which are the extensive interactions that occur between metal and refractory. There is a need to improve understanding of this interaction so that suitable refractory systems can be identified on a less empirical basis.

It is well known that titanium alloys cannot be successfully cast using investment moulds with zircon/silica facecoats. Indeed this is considered to be the 'worst case scenario' with regard to the alloy/ceramic reactions, with the interacted surface of the casting having to be removed after casting by mechanical or chemical means which is a time consuming and costly process. This paper details the results of research aimed at producing ‘alternative’ face-coat materials to reduce/eliminate the extensive surface reactions. Several widely available refractory systems are tested and conclusions are drawn as to which would be most suitable to allow these difficult alloys to be routinely and successfully cast.