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Owing to their low density and attractive high-temperature properties,gamma titanium aluminide alloys (TiAl alloys,hereafter) have significant potential application in the aerospace and automobile industries,in which these materials may replace the heavier nickel-based superalloys at service temperatures of 600 - 900℃.Investment casting of TiAl alloys has become the most promising cost-effective technique for the manufacturing of TiAl components.Ceramic moulds are fundamental to fabricating the TiAl casting components.In the present work,ceramic mould with a zirconia primary coat was designed and fabricated successfully.Investment casting of TiAl blades and tensile test of specimens was carried out to verify the correctness and feasibility of the proposed method.The tensile test results indicate that,at room temperature,the tensile strength and the elongation are about 450 MPa and 0.8％,respectively.At 700℃,the tensile strength decreases to about 410 MPa and the elongation increases to 2.7％.Microstructure and mechanical properties of investment cast TiAl alloy are discussed.