Thermal stability study of vacancy-type defects in commercial pure Titanium using positron annihilation spectroscopy Articles uri icon

publication date

  • May 2016

start page

  • 1

end page

  • 8

volume

  • 18

international standard serial number (ISSN)

  • 1438-1656

abstract

  • Commercially pure (CP) titanium has been subjected to hydrostatic extrusion at room temperature at true strains ranging from 0.70 to 3.24. Isochronal thermal treatments, from room temperature to 1 200 °C, have been performed and the thermal stability of the deformation-induced defects has been studied by positron annihilation spectroscopy (PAS). In non-annealed samples, vacancy-type defects are formed and interact with iron impurities. These defects are not stable near room temperature. Saturation of the positron annihilation parameters is not observed for cumulative true strains as large as 3.24, due to dynamic recovery during the extrusion process. TEM experiments confirm the formation of iron-rich precipitates. Vacancy-type defects and vacancy&-impurity complexes anneal out at temperatures &;8776#700 °C.