TiAl基合金定向凝固中领先相的确定及影响因素

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

摘要:

TiAl基合金因其优异的高温性能及较低的密度成为近年的研究热点，室温塑性是其走向工程化应用最主要的障碍。通过定向凝固技术控制TiAl基合金片层取向与生长方向平行时，可有效提高其综合力学性能，领先相的选择及生长取向的控制是TiAl基合金片层取向控制的关键因素。本文综述了定向凝固TiAl合金领先相的类型及生长取向的几种确定方法，及其生长取向的影响因素，最后总结了领先相生长取向控制的研究方向，对制备定向凝固TiAl基合金叶片具有重要的指导意义。

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.