Abstract:The effects of binder, additive and sintering temperature on the properties of calcia as a mold material used for titanium-aluminum alloys have been studied. The results showed that the solution of CaCl₂C₂H₅OH is the best binder for calcia, the additive of CaF₂  not only increases the strength but also the antiwatering property of calcia; sintering at 900~1 000℃is adaptable. The contamination of calcia on titaniumaluminum alloy castings has been studied, and the experimental results showed that the thickness of contamination is less than 15μm.

Key words: titanium-aluminum alloy　mold material　calcia　casting