中文摘要：

研究了元素Y和Nb对用熔体快淬法制备的TiAl基快速凝固合金组织及性能的影响。发现添加Y的快速凝固TiAl合金主要为等轴晶,主要组成相为α2和少量的γ相。随着Y含量的增加,γ相的含量增加,快速凝固TiAl合金的组织逐渐细化。不同Nb含量的快速凝固TiAl合金的组织为块状结构和层片状结构,主要由γ和α2两相组成,层片间距显著细化,为15～17nm。快速凝固TiAl合金的硬度比其铸态合金显著提高。

英文摘要：

The effects of Y and Nb on the microstructure and mechanical properties of rapidly solidified TiAl alloys were investigated.Results show that the rapidly solidified TiAl alloys with various Y contents are of equiaxed microstructure,and composed mainly of α2 and a few amount of γ phase.With Y content increasing,the volume fraction of γ phase is increased and the microstructure of the TiAl alloys is gradually refined.The alloys with various Nb contents show lamellar structure with reduced interlamellar spacings of 15-17 nm and massive structure.γ and α2 are also the two main phases for rapidly solidified TiAl alloys with various Nb addition.The hardness of rapidly solidified TiAl alloys is higher than that of the conventionally cast TiAl alloys.