Research Progress of the Primary Phase Growth Direction in Directional Solidified TiAl Alloys

Abstract:

γ-TiAl alloys are potentially used as high-temperature structural materials with a high specific strength and low density. The mechanical properties of γ-TiAl alloys are extremely anisotropic with respect to the lamellar orientation of the microstructures. A balance combination of room-temperature ductility and strength can be achieved when the lamellar orientation are aligned parallel to the growth direction. The lamellar orientation can be alliged by directional solidification technique. However, the orientation of the primary phase have great influence on room temperature lamellar orientation. This paper reviewed the research progress of the primary phase growth direction in directional solidified TiAl alloys, the method for determined the orientation of primary high temperature phase and effects of solidification conditions and interface on the growth direction of primary phase are presented. Finally, the future research direction is summarized.