Abstract
Titanium alloys have been widely used in the structural parts of deep-sea equipment and aviation industries. In this paper, the effects of loading frequency and specimen geometry on the high cycle and very high cycle fatigue life of the high strength titanium alloy Ti-6Al-2Sn-2Zr-3Mo-X is investigated by conventional fatigue test and ultrasonic frequency fatigue test. The results indicate that ultrasonic frequency could enhance the fatigue life of the highstrength titanium alloy compared with that under conventional frequency, and the frequency effect is related to the stress amplitude. This phenomenon is explained by the heat generation in specimens and heat dissipation, in combination with the high strain rate leading to the higher yield strength in the ultrasonic fatigue test. Moreover, it is indicated that the effect of specimen geometry on the fatigue life of the highstrength titanium alloy could be evaluated from the view of control volume.
Highlights
Ultrasonic fatigue testing systems have been widely used in fatigue tests, especially for very high cycle fatigue (VHCF) due to its high efficiency [1,2,3,4,5,6,7]
This paper studies the effects of loading frequency and specimen geometry on the high cycle
This paper studies the effects of loading frequency and specimen geometry on the high cycle fatigue and VHCF life of the high strength titanium alloy Ti-6Al-2Sn-2Zr-3Mo-X by conventional fatigue and VHCF life of the high strength titanium alloy Ti-6Al-2Sn-2Zr-3Mo-X by conventional fatigue test and ultrasonic frequency fatigue test
Summary
Ultrasonic fatigue testing systems have been widely used in fatigue tests, especially for very high cycle fatigue (VHCF) due to its high efficiency [1,2,3,4,5,6,7]. Morrissey and Nicholas [8] showed that the effect of frequency including the temperature rise during ultrasonic fatigue test was negligible for a Ti-6Al-4V alloy in a VHCF regime. As the specimens of Heat C developed only surface failure, the ultrasonic fatigue test showed higher fatigue strength than that under a conventional fatigue test. Guennec et al [10] showed that the ultrasonic frequency test had great influence on the fatigue strength of a low carbon steel compared to that under conventional frequency test. In their results, the frequency effect was discussed by the micro-plasticity behavior such as the stress-strain hysteresis loop and the local misorientation. The results by Morrissey et al [11] indicated that the effect of Materials 2018, 11, 1628; doi:10.3390/ma11091628 www.mdpi.com/journal/materials
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: 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.
