한국주조공학회

The main objectives were to investigate the suitability of CaO crucible for melting TiA1 alloys and to develop investment mold for investment casting of TiAl alloys. TiAl alloy specimen were prepared by plasma arc furnace under argon atmosphere. After melting ofTiAl alloy using CaO crucible, the results showed that there is little contamination ofoxygen in the TiAl bulk. Conan-tional vacuum induction furnaces can be readily adaptable to produce cast parts of TiA1 without high skilled techniques. The determination of optical metallography and microhardness profiles in investment cast TiAl alloy rods has allowed the gradation ofthe relative thermal stability of the oxides examined. The molds used for the present study were ZrO2, A1203, CaO stabilized ZrO2 and ZrSiO4. Even although high temperature of mold preheating, Al,O3 mold is a promising mold material for investment casting of TiAl alloys in terms ofthermal stability, cost and handling strength. It is important to take thermal stability antpreheating temperature ofmold into consideration for investment casting ofTiAl alloys.

TiAl alloys, investment casting, CaO crucible, thermal stability, mold preheating temperature, A403 mold