In-situ observations of R-phase transformation in a Ti50Ni48Fe2 alloy by electron microscopy

T. Tamiya, D. Shindo, Yasukazu Murakami, Y. Bando, K. Otsuka

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35 Citations (Scopus)


The R-phase transformation in a Ti50Ni48Fe2 alloy was studied by in-situ electron microscopy with double-tilt cooling stages and an energy-filter, and the controversial incommensurability in the early stage of the transformation was examined by using imaging plates, which have high sensitivity and are easy to access to computer analysis. As a result, the transformation was shown to proceed in the following way. The R-phase transformation starts at Rs point, where the electrical resistance starts to increase, from the B2 parent phase with weak diffuse scattering to the commensurate R-phase with a sharp interface. Thus, the transformation is a first order throughout, and the temperature hysteresis represents the two-phase region of the B2 parent and the commensurate R-phase.

Original languageEnglish
Pages (from-to)714-723
Number of pages10
JournalMaterials Transactions, JIM
Issue number7
Publication statusPublished - 1998 Jul


  • Commensurate
  • Electron microscopy
  • Energy-filtering
  • Imaging plate
  • Incommensurate
  • Martensitic transformation
  • R-phase transformation
  • Shape memory effect
  • Superlattice
  • Titanium-nickel-iron alloy

ASJC Scopus subject areas

  • Engineering(all)

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