About this Abstract |
| Meeting |
MS&T25: Materials Science & Technology
|
| Symposium
|
Advances in Titanium Technology
|
| Presentation Title |
Deformation Substructures and Shear Localization at Basal Twist Boundaries in Fatigued Ti-6Al-4V |
| Author(s) |
Nadib Akram, Baris Yavas, Christopher Collins, Asa Frye, Vasisht Venkatesh, Adam L. Pilchak, David U. Furrer, Iuliana Cernatescu, Mark Aindow |
| On-Site Speaker (Planned) |
Mark Aindow |
| Abstract Scope |
Recent studies have suggested that basal twist grain boundaries (BTGBs) formed between suitably oriented primary alpha grains may play an important role in fatigue crack nucleation for alpha/beta Ti alloys. There is evidence for the localization of shear at such boundaries, but the origins of this behavior are not well understood. Here we report studies on the low cycle fatigue behavior of cross-rolled Ti-6Al-4V plate material that contains a well-defined population of BTGBs. It is shown that samples tested to failure exhibit secondary cracks, and in each case these cracks are associated with a BTGB oriented to give a high resolved shear stress. Transmission electron microscopy studies on the BTGBs show that in each case the deformations substructure is very localized at the boundary, even though the grains are in “soft” orientations. The reasons for the localization and the role of this behavior in fatigue crack nucleation will be discussed. |