中文摘要：

TiAl合金作为新型轻质高温结构材料，其熔炼及制备技术难度大、铸态组织较粗大、室温塑性较低和高温抗氧化能力的不足成为限制其应用的关键。从材料制备成形和合金成分两个角度综述稀土元素Y在TiAl基合金中应用的研究进展，总结国内外对Y2O3陶瓷坩埚和型壳面层在TiAl合金熔炼和精密铸造及制备成形过程中的研究进展；阐述稀土元素Y在合金中的形态与分布及其对合金铸态组织的细化及作用机理，并分析Y对合金室温力学性能和抗氧化性能的影响，对Y在TiAl基合金中的进一步研究应用提出建议。

英文摘要：

As a highly promising material for high-temperature structural applications, the weakness of TiAl alloy such as vulnerability for instance, smelting process controlling, coarse casting microstructure, low room temperature ductility and poor high temperature anti-oxidation properties becomes the key factors to limit its application. From the perspectives of refractory application and alloying elements, the status of the research on rare earth yttrium （Y） in TiAl based alloy was summarized. The domestic and foreign researches of Y 2 O 3 worked as ceramic crucibles and shell surface in TiAl based alloy on smelting process and investment casting were stated, and the mechanism of contamination and interaction between alloy and refractory was discussed. The morphology and distribution of element Y in alloy matrix and its refining effect on the as-cast grain and lamellar spacing as well as the refinement mechanisms were expounded emphatically. The complex influence of rare earth element Y on room temperature tensile strength and ductility as good as enhanced temperature oxidation resistance were analyzed systematacially. Some suggestions for the research on rare earth element Y inγ-TiAl based alloys were proposed.