Investigation of Interfacial Reactions between TiAl Alloy and Crucible Materials during Directional Solidification Process

Abstract:

Interfacial reactions between Ti-47Al alloy and crucible materials of Al2O3, ZrO2, and graphite during directional solidification process were investigated. By the OM and SEM observation of solidification microstructure, the interfacial reaction between TiAl alloy and Al2O3 crucible was serious, and a large number of α-Al2O3 inclusion formed in the solidification microstructure. The interfacial reaction between TiAl alloy and ZrO2 crucible occurred only on the sample surface, but the crucible was not stable at high temperature and a tack coating was formed, clinging tightly with TiAl alloy. C element in the graphite crucible changed the original solidification path of TiAl alloy, and club-shaped γ-TiAl phases formed.

Key words:TiAl alloy; directional solidification; interfacial reaction