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Atomic origins of radiation-induced defects and the role of lamellar interfaces in radiation damage of titanium aluminide alloy irradiated with Kr-ions at elevated temperature

Journal Article


Abstract


  • The irradiation microstructure of a titanium aluminide (TiAl) alloy subjected to in situ transmission electron microscope (TEM) irradiation with 1 MeV Kr ions at the elevated temperature of 873 K was investigated. Triangle and large hexagon shaped volume defects were observed within the γ-TiAl phase in the TEM images of the irradiated microstructure. High resolution TEM images and composition analyses revealed that the volume defects were vacancy-type stacking fault tetrahedra (SFTs). Molecular dynamic simulations showed that the increased diffusion coefficient at the elevated temperature promoted the movement and aggregation of vacancies, leading to the formation and growth of SFTs in the irradiated FCC γ phase. The lamellar interfaces in the irradiation microstructure were more effective for acting as strong sinks to absorb the primary point defects and defect clusters at the elevated temperature. The initial defects at the interfaces of the TiAl alloy enhanced the sink strength of the material and played an important role in refining SFTs near the lamellar interfaces.

UOW Authors


  •   Zhu, Hanliang (external author)
  •   Qin, Mengjun (external author)
  •   Aughterson, Robert (external author)
  •   Wei, Tao (external author)
  •   Lumpkin, Gregory R. (external author)
  •   Ma, Yan (external author)
  •   Li, Hui Jun.

Publication Date


  • 2019

Citation


  • Zhu, H., Qin, M., Aughterson, R., Wei, T., Lumpkin, G., Ma, Y. & Li, H. (2019). Atomic origins of radiation-induced defects and the role of lamellar interfaces in radiation damage of titanium aluminide alloy irradiated with Kr-ions at elevated temperature. Acta Materialia, 172 72-83.

Scopus Eid


  • 2-s2.0-85064897323

Number Of Pages


  • 11

Start Page


  • 72

End Page


  • 83

Volume


  • 172

Place Of Publication


  • United Kingdom

Abstract


  • The irradiation microstructure of a titanium aluminide (TiAl) alloy subjected to in situ transmission electron microscope (TEM) irradiation with 1 MeV Kr ions at the elevated temperature of 873 K was investigated. Triangle and large hexagon shaped volume defects were observed within the γ-TiAl phase in the TEM images of the irradiated microstructure. High resolution TEM images and composition analyses revealed that the volume defects were vacancy-type stacking fault tetrahedra (SFTs). Molecular dynamic simulations showed that the increased diffusion coefficient at the elevated temperature promoted the movement and aggregation of vacancies, leading to the formation and growth of SFTs in the irradiated FCC γ phase. The lamellar interfaces in the irradiation microstructure were more effective for acting as strong sinks to absorb the primary point defects and defect clusters at the elevated temperature. The initial defects at the interfaces of the TiAl alloy enhanced the sink strength of the material and played an important role in refining SFTs near the lamellar interfaces.

UOW Authors


  •   Zhu, Hanliang (external author)
  •   Qin, Mengjun (external author)
  •   Aughterson, Robert (external author)
  •   Wei, Tao (external author)
  •   Lumpkin, Gregory R. (external author)
  •   Ma, Yan (external author)
  •   Li, Hui Jun.

Publication Date


  • 2019

Citation


  • Zhu, H., Qin, M., Aughterson, R., Wei, T., Lumpkin, G., Ma, Y. & Li, H. (2019). Atomic origins of radiation-induced defects and the role of lamellar interfaces in radiation damage of titanium aluminide alloy irradiated with Kr-ions at elevated temperature. Acta Materialia, 172 72-83.

Scopus Eid


  • 2-s2.0-85064897323

Number Of Pages


  • 11

Start Page


  • 72

End Page


  • 83

Volume


  • 172

Place Of Publication


  • United Kingdom