Plastic strain and grain size effect on high-pressure phase transformations in nanostructured TiO2 ceramics

Hadi Razavi-Khosroshahi, Kaveh Edalati, Mokoto Arita, Zenji Horita, Masayoshi Fuji

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)

Abstract

Anatase TiO2 was severely deformed using high-pressure torsion and the effect of plastic strain and grain size on phase transformations was investigated. A high-pressure TiO2-II phase (columbite) with the orthorhombic structure was formed under pressures of 1 and 6 GPa. Fraction of TiO2-II increased with increasing the plastic strain and remained stable at ambient pressure. Microstructural analysis showed that TiO2-II was stabilized in grains with sizes less than ~ 15 nm because of high energy barrier for reverse phase transformation, while larger grains had the anatase structure. Large densities of oxygen vacancies and dislocations were also formed after severe plastic deformation.

Original languageEnglish
Pages (from-to)59-62
Number of pages4
JournalScripta Materialia
Volume124
DOIs
Publication statusPublished - Nov 1 2016

All Science Journal Classification (ASJC) codes

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys

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