Hot deformation behavior of a layered heterogeneous microstructure TiAl alloy prepared by selective electron beam melting

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

3 Scopus Citations
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Author(s)

  • Hui Tao
  • Huizhong Li
  • Weiwei He
  • Huixia Li
  • Yixuan Che
  • Ling Li
  • Li Wang
  • Xiaopeng Liang

Detail(s)

Original languageEnglish
Article number113986
Journal / PublicationMaterials Characterization
Volume212
Online published16 May 2024
Publication statusPublished - Jun 2024

Abstract

TiAl-based alloys are known for their exceptional high-temperature properties but suffer from low hot workability. The emergence of additive manufacturing (AM) technology significantly decreases the workability requirement, while the microstructure heterogeneities in AMed TiAl are troublesome. This paper explores the hot deformation behavior and microstructure evolution of a layered heterogeneous microstructure TiAl alloy prepared by selective electron beam melting. The Arrhenius constitutive model with strain compensation was established, and hot processing maps were constructed. The microstructure showed that at the initial stage of deformation, a large number of dislocation slips occur preferentially in the soft coarse-grained layers. With the increase of strain, dislocation accumulation in heterogeneous interfaces, and dynamic recrystallization (DRX) occurs. Eventually, the coarse-grained region is constantly occupied by fine DRX grains. A high density of deformation twins at high strain rates further promotes the formation of tiny DRX grains. When the hot compression temperature reaches 1200 °C, the initial alternative fine-grained and coarse-grained hetero-structure transforms into duplex (DP) and near-lamellar (NL) microstructure, and microstructure heterogeneity is eliminated. The results enhance understanding of the hot deformation behavior of heterogeneous microstructure TiAl alloys. © 2023

Research Area(s)

  • Dynamic recrystallization (DRX), Heterogeneous microstructure, Hot deformation, Processing maps, Selective electron beam melting, TiAl alloy

Citation Format(s)