Abstract
High frequency fatigue tests were carried out with a 20kHz ultrasonic testing facility to investigate the cyclic deformation behavior of Ti6Al4V in the Very High Cycle Fatigue (VHCF) regime in detail. The S,Nf-curve at the stress ratio R=−1 shows a significant decrease of the tolerable stress amplitude and a change from surface to subsurface failures in the VHCF regime for more than 107 cycles. Quantitative microscopic investigations of the distribution of the α- and β-phase of Ti6Al4V show that inhomogeneities in the phase distribution exist at subsurface crack initiation sites. This could be proven in scanning electron microscopic as well as light microscopic investigations. Beside the primary fatigue crack additional defects like micro cracks and crack clusters were observed in fatigued specimens. SEM-investigations of specimens loaded up to 1010 cycles without macroscopic failure show irreversible microstructural changes and defects in the subsurface volume. Two step tests were performed to evaluate the influence of fatigue induced defects observed in specimens which did not fail within 1010 cycles.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.