Work-hardening and twinning behaviors in a commercially pure titanium sheet under various loading paths

In this study, the work-hardening and twinning behaviors in a commercially pure titanium sheet were examined under various loading paths including reverse loading. The yield stress was identical between tension and compression, while the work-hardening was slightly larger during compression than during tension. These tendencies were the same in both the rolling and transverse directions. When the sheet was subjected to reverse loading, the Bauschinger effect was observed during both tension-compression and compression-tension. The tendency in the Bauschinger effect was nearly independent of the strain path tested in the present study. Concerning the twinning, the activities of {101¯2} tensile twinning, {112¯2} compressive twinning, and {112¯1} tensile twinning were observed during tension. Alternatively, during compression, the activity of {101¯2} tensile twinning was observed and was much larger than that during tension. When the sheet was subjected to tension following compression, detwinning occurred. Although the trend in the activity of twinning was similar to that of a magnesium alloy sheet, the behavior observed in the stress-strain curves was quite different from that of a magnesium alloy sheet. Based on the results presented, the effect of twinning and detwinning activities on the work-hardening behavior was discussed.