Modeling of titanium aluminides turbo-charger casting

Abstract

The castability of titanium aluminide (TiAl) turbo-charger was investigated with various casting parameters. The fluidity of TiAl alloys increased with mold preheating temperature and centrifugal force. The thermo-physical variables estimated by casting process were applied to the modeling of TiAl turbo-charger casting using the Magmasoft ®. In the case of real casting process, there were many misruns and cold-shuts due to low fluidity of molten TiAl alloy. However, in the modeling, molten TiAl alloys never stop even though the turbo-charger has both the curvature and thin wall parts. Therefore, there were no major defects such as misruns and cold-shuts in the modeling process. The gap between casting and modeling remains in TiAl alloy turbo-charger casting since the modeling process cannot explain the microstructural evolution during solidification and metal–mold reaction between mold materials and TiAl alloy.