Fatigue behavior of ultrafine-grained Ti–6Al–4V ‘ELI’ alloy for medical applications

In this study the cyclic deformation behavior and fatigue lives of Ti–6Al–4V ELI (extra low interstitials) alloy with conventional grain sized and ultrafine-grained (UFG) microstructure are investigated. The UFG condition was obtained by a combination of equal channel angular pressing followed by thermomechanical treatment. Fatigue experiments were carried out under strain as well as under stress control using plastic strain amplitudes ranging from 3 × 10−4 to 5 × 10−3 and stress amplitudes ranging from 550 to 670 MPa, respectively. Based on the results obtained, it can be concluded that the UFG microstructure results in a significant enhancement of the fatigue properties of the alloy.