Research On The Casting Properties Of Ti-43Al-9V Intermetallic Compounds

TiAl-based intermetallic compounds show large strength-to-weight ratio and excellent properties at high temperatures. Recently People have especially paid attention to studyγ- TiAl-based intermetallic compounds. The investment casting can be used to the cast parts ofγ- TiAl-based intermetallic compounds in order to reduce cost. Improving the properties of casting, the centrifugal casting is the import approaches that have been used for the production ofγ- TiAl-based intermetallic compounds. In this paper, the degree to Ti-43Al-9V casting shrinks have been measured, the fluidity and filling property of Ti-43Al-9V alloy in the mould are researched. Casting defects of Ti-43Al-9V used the centrifugal casting is also researched. The cast Ti-43Al-9V alloy microstructure , and the heat cracks defects , and the reactivity between Ti-43Al-9V alloy and model are observed.Rotate speed of the centrifugal casting, the temperature of investment model, casting temperature and model material can affect the fluidity of Ti-43Al-9V.the fluidity will be improved at high rotate speed. Because of low reactivity between Ti-43Al-9V with Y₂O₃, the fluidity will be better in Y₂O₃ model.Ti-43Al-9V has great casting shrinks in the process of cooling but the ability of compensating shrinks is bad. The casting defects of Ti-43Al-9V in stick model are microporosity and the hole formed by shrinks at the centrifugal casting. The immixture air hole is the main air defects of casting.The serious heat cracks defects will be find at hot section in Ti-43Al-9V casting parts when the temperature of model is low. The reactivity between the model and the Ti-43Al-9V alloy is not serious,because the centrifugal effect make the liquid of Ti-43Al-9V alloy wash out the wall of model seriously . The layer of reactivity is thin. the casting microstructure is the fully lamellar structure. the size of the fully lamellar structure will be large or small at different casting conditions.