On the occurrence of a nano-scale fcc phase in thin-foil specimens of titanium alloys

Hoi Pang Ng, Colleen Bettles, Barry Muddle

Research output: Chapter in Book/Report/Conference proceedingConference PaperResearchpeer-review

Abstract

This paper reports an unknown phase occurring in the thin-foil specimens of a range of metastable titanium alloys prepared by conventional ion-beam milling. The phase demonstrates an apparent face-centered-cubic (f. c. c. ) lattice structure and exists in foil specimens prepared from alloys having an intermediate to high [Moeq](i. e. >11). This phase can be distinguished from the conventional hydride phase(s) that are known to arise in Ti alloys thinned with acid-based electrolytes, or the ion-beam-induced fee Ti phases due reportedly to interfacial stresses associated with deposited multilayered structures. Electron microscopy revealed that the f. c. c. phase assumes a nano-scale domain network rather than the isolated structural entities that would be expected from a nucleation and growth reaction. The f. c. c. phase maintains an orientation relationship with the (matrix such that [110]β || [111]fcc;the (002)β and (220)fcc, plane sets are related by a rotational angle δ, where δ varies from 0 to 2°. It is shown that the phase gives rise to diffuse scattering in the electron diffraction pattern, strongly resembling that exhibited by the athermal ω phase, yet with a dissimilar distribution of intensity maxima along the loci of the diffuse scattering. The effect of specimen preparation temperature on the occurrence of the f. c. c. phase is reported. The possibility of the phase originating from a lattice displacement controlled reaction is discussed.

Original languageEnglish
Title of host publicationProceedings of the 12th World Conference on Titanium (TI-2011)
Subtitle of host publication19-24 June, 2011; Beijing China
EditorsLian Zhou, Hui Chang, Yafeng Lu, Dongsheng Xu
PublisherScience Press
Pages568-572
Number of pages5
Volume1
ISBN (Print)9787030338990
Publication statusPublished - 2012
EventThe World Conference on Titanium 2011 - China National Convention Center, Beijing, China
Duration: 19 Jun 201124 Jun 2011
Conference number: 12th
https://books.google.com.au/books/about/Ti_2011_Proceedings_of_the_12th_World_Co.html?id=NrJwMwEACAAJ&redir_esc=y

Conference

ConferenceThe World Conference on Titanium 2011
Abbreviated titleTi 2011
CountryChina
CityBeijing
Period19/06/1124/06/11
Internet address

Keywords

  • Face centered cubic (fee)
  • Ion beam milling
  • Thin foil
  • Titanium (Ti)
  • Transmission electron microscopy

Cite this