On the work hardening of titanium: new insights from nanoindentation

Arnas Fitzner, Jack Palmer, Ben Gardner, Matthew Thomas, Michael Preuss, Joao Quinta da Fonseca

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12 Citations (Scopus)


Nanoindentation was used to probe the local slip resistance in CP-Ti deformed in compression to different extents. Changes in hardness in the deformed grains and twins were compared with the change in flow stress measured during deformation, with the aim to elucidate the relative contribution of slip and twinning to the work hardening of Ti alloys. The hardness values were calibrated with measurements on binary Ti–Al alloys. The hardness increased only slightly with deformation and cannot explain the observed work hardening. Although twinned regions were found to be harder than the parent grains, this increase was found to be small once the effect of crystal orientation was accounted for. The increase in hardness in the twins was slightly higher for compressive twins than for tensile twins. It is proposed that this modest hardness increase in the twins is more consistent with the presence of twinning stresses than with a change in the local flow stress caused by dislocation interactions. The implications of these findings to the work hardening of CP titanium are discussed.

Original languageEnglish
Pages (from-to)7961-7974
Number of pages14
JournalJournal of Materials Science
Issue number10
Publication statusPublished - 30 May 2019
Externally publishedYes

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