Ti44Al6Nb-based alloy ingots with different cerium (Ce) contents (0, 0.05, 0.10, 0.15, 0.20; at%) were prepared by non-consumable vacuum arc smelting furnace (WK-II). The surface quality, macrostructure, microstructure, compressive properties and fracture morphology of these ingots were studied. The results show that Ce has few influences on the surface quality. Ce can refine grain size and the average grain size decreases from 0.50 to 0.19 mm with the increase of Ce content. Meanwhile, the microstructure morphology of these ingots changes from large lamellar microstructure to dual-phase microstructure. With addition of Ce, CeO and AlCe 3 are formed during melting and solidifying, which act as the core of heterogeneous nucleation and refine the grain. The compressive testing results show that Ce can improve strength and ductility. The ultimate compressive strength increases from 1156.2 to 1472.2 MPa with Ce content increasing from 0 at% to 0.20 at%. The compression ratio is improved from 10.2 % to 15.3 % with Ce content increasing from 0 at% to 0.10 at%. The refined crystalline strengthening and grain boundary strengthening are the main reasons for the improvement of compressive property.

中文翻译：

---

不同铈含量Ti44Al6Nb合金的组织和力学性能

采用非自耗真空电弧熔炼炉（WK-II）制备了不同铈（Ce）含量（0、0.05、0.10、0.15、0.20；at%）的Ti44Al6Nb基合金锭。研究了这些铸锭的表面质量、宏观结构、微观结构、压缩性能和断口形貌。结果表明，Ce对表面质量的影响很小。Ce可以细化晶粒，随着Ce含量的增加，平均晶粒尺寸从0.50mm减小到0.19mm。同时，这些铸锭的组织形态从大片状组织转变为双相组织。Ce的加入，在熔化和凝固过程中形成CeO和AlCe 3 ，它们是异相形核的核心，细化晶粒。压缩试验结果表明，Ce可以提高强度和延展性。随着 Ce 含量从 0 at% 增加到 0.20 at%，极限抗压强度从 1156.2 MPa 增加到 1472.2 MPa。随着 Ce 含量从 0 at% 增加到 0.10 at%，压缩比从 10.2% 提高到 15.3%。细晶强化和晶界强化是压缩性能提高的主要原因。