Effects of Contact Pressure on Fretting Fatigue Characteristics of Ti-4.5Al-3V-2Mo-2Fe with Acicular Alpha Structure

摘要

The effects of microstructure and contact pressure on fretting fatigue characteristics of Ti-4.5Al-3V-2Mo-2Fe conducted with annealing at 1123 K and 1223 K were investigated in this study. Fretting fatigue tests in low and high cycle fatigue life regions of the alloys with equiaxed a and acicular a structures were carried out at each contact pressure of 10, 15, 30, 45, 75, 105 and 153 MPa. In the alloy with equiaxed a structure, fretting fatigue strength tends to be very low at contact pressures of 10 MPa and 15 MPa in low and high cycle fatigue life regions, respectively. Furthermore, fretting fatigue strength tends to be nearly constant at the contact pressure over 45 MPa in each fatigue life region. On the other hand, in the alloy with acicular alpha structure, fretting fatigue strength tends to be very low at contact pressures of 15 MPa and 30 MPa in low and high cycle fatigue life regions, respectively. Furthermore, fretting fatigue strength tends to be nearly constant at contact pressures of 45 MPa and over 30 MPa in low and high fatigue life regions, respectively.