# Fileset

[20251215Ti-O alloy_Morita.docx](https://mdr.nims.go.jp/filesets/e84b1c95-8ced-4187-8554-b48946ce6bf2/download)

## Creator

Motoaki Morita, Shogo Hara, [Yoshiaki Toda](https://orcid.org/0000-0002-8343-2890), Osamu Umezawa

## Rights

[In Copyright](http://rightsstatements.org/vocab/InC/1.0/)

## Other metadata

[Role of Oxygen in Work Hardening and Fatigue Deformation of {0001}10-10> Textured Titanium Alloys](https://mdr.nims.go.jp/datasets/38a6ccbb-7554-4df6-8422-efaf00704842)

## Fulltext

Abstract TemplateRole of Oxygen in Work Hardening and Fatigue Deformation of {0001}⟨10–10⟩ Textured Titanium AlloysMotoaki Morita1, Shogo Hara1, Yoshiaki Toda2, Osamu Umezawa31First author's affiliation2National Institute of Materials Science3Yokohama National Universitye: morita@kaiyodai.ac.jpTi-0.21mass%O and Ti-0.71mass%O with {0001}<10-10> texture were prepared, and their tensile and fatigue properties were investigated. In tensile tests, Ti-0.71mass%O exhibited higher elongation than that of Ti-0.21mass%O. Furthermore, the work-hardening rate of Ti-0.71 mass%O remained high until the end of deformation. The pyramidal slip in Ti-0.71mass%O alloy was activated, and the number of active slip systems increased. The enhanced work-hardening behavior is likely associated with increased dislocation interactions promoted by the texture-controlled slip activity.Cyclic and dwell fatigue tests were conducted on both Ti–O alloys. Ti–0.21 mass% O alloy exhibited significant elongation and ductile fracture under both cyclic and dwell fatigue at a cyclic stress of 90% of the 0.2% proof stress. In contrast, Ti–0.71 mass%O alloy showed lower elongation and the formation of localized strain fields near grain boundaries. Similar fatigue deformation behavior was observed even when the cyclic stress was reduced to 60% of the 0.2% proof stress. Ti–0.71 mass% O alloy contained a high density of pinned, sessile dislocations, which limited dislocation pile-up lengths and hindered the activation of dislocation sources such as the Frank–Read source. Consequently, oxygen addition modified the fatigue deformation behavior by limiting dislocation multiplication under cyclic and dwell loading.