TiAl基合金(TiAl基金属间化合物)，被认为是一种理想的新型轻质高温结构材料，在当代民用工业、兵器工业以及航空航天等领域具有广阔的应用前景。然而TiAl基合金脆性较大，传统的成形方法难以制备出复杂结构的构件，严重制约了该合金的推广与应用。选区熔化3D打印是按照CAD模型的分层切片数据，以激光或者电子束为高能量热源逐层扫描熔化粉末，逐层堆积，直接实现构件的制造，代表了TiAl基合金成形最前沿、最新颖的技术。基于激光选区熔化成形(SLM)与电子束选区熔化成形(SEBM)制备TiAl基合金的最新研究成果，重点归纳了成形过程中常见缺陷的形成原因以及控制措施，详细阐述了工艺参数对成形质量、微观组织以及力学性能的影响规律，然后对比分析了SLM和SEBM制备TiAl基合金的优缺点。国内外的研究结果表明，控制TiAl合金的开裂倾向是SLM制备TiAl合金需要解决的首要问题，也是提高成形件致密度，改善力学性能的基础;而SEBM技术通过工艺优化，能够较好地抑制TiAl合金的开裂，获得高致密度成形件，其力学性能可以达到传统锻件、铸件的水平，更加适合TiAl合金的3D打印。最后对选区熔化3D打印TiAl基合金的研究方向提出了建议。

TiAl-based alloys (TiAl-based intermetallics) are considered as an ideal novel light-weight high temperature structural material, which have a broad application prospect in civilian, weapon and aerospace industries. However, due to the brittleness of TiAl-based alloys, it is difficult to produce complex structural components by traditional forming methods, seriously restricting the popularization and the application of TiAl-based alloys. According to the layered slice data of the CAD model, selective melting 3D printing uses laser or electron beam as high energy heat source to scan and melt the powder layer by layer, and the manufacturing of parts is directly realized by the layer by layer stacking method. Selective melting 3D printing represents the most advanced and novel technology of TiAl-based alloys forming. In this paper, based on the latest research results of TiAl-based alloys prepared by selective laser melting (SLM) and selective electron beam melting (SEBM), the formation causes and control measures of common defects in the forming process are summarized emphatically, and the influence laws of process parameters on forming quality, microstructure and mechanical properties are elaborated in detail. Furthermore, the advantages and disadvantages of SLM and SEBM to produce TiAl-based alloys are compared and analyzed. The Chinese and international research results show that controlling the cracking tendency of TiAl alloys is the most important problem to be solved for TiAl alloys prepared by SLM, and is also the basis for improving the density and mechanical properties of the formed parts. By optimizing the process, SEBM can better restrain the cracking of TiAl alloys and obtain high density formed parts, of which the mechanical properties can reach the level of traditional forgings and castings. Therefore, SEBM is more suitable for 3D printing of TiAl alloys. Suggestions for further development on selective melting 3D printing of TiAl-based alloys are proposed finally.