Temperature dependence of cyclic deformation behaviour in Ti3Al single crystals was investigated between 300°C and 800°C focusing on the cyclic hardening, deformation substructure and orientation dependence of fatigue life and fracture behaviour. The saturated bundled structure (SBS) composed of numerous edge dislocations parallel to  was observed below 500°C accompanied by edge dislocation dipoles and debris, while dislocation networks composed of three different a/3〈12̄10〉-type dislocations were formed at 800°C. Cyclic hardening was moderated with increasing temperature but anomalous cyclic hardening was observed at 800°C due to the formation of the dislocation networks. The fatigue life at 800°C showed strong orientation dependence: the fatigue resistance was related to the Schmid law under prism slip but when the basal or pyramidal slip is expected to be operative instead of the prism slip, fracture occurred at a lower stress before yielding.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Ceramics and Composites
- Polymers and Plastics
- Metals and Alloys