Development of Ceramic Moulds with Zirconia Primary Coat for Investment Casting of Gamma Titanium Aluminide Based Alloys

The fabrication of ceramic moulds with zirconia primary coat for investment casting of gamma titanium aluminide based alloys (hereafter called TiAl alloys) was described in this study. The microstructures and fracture strength of ceramic moulds were characterized. The fracture strength and surface roughness of the ceramic moulds with zirconia primary coat were sufficient for the TiAl investment casting. TiAl blades were used for the technology demonstration in producing TiAl components. TiAl castings produced by the ceramic moulds exhibited an average surface roughness (Ra ) of 6 μm.