Contact pressure and fretting fatigue characteristics of highly workable titanium alloy with equiaxed α and Widmanstätten α structure

The effects of microstructure and contact pressure on fretting fatigue characteristics of a Ti-4.5Al-3V-2Mo-2Fe alloy with a Widmanstätten α structure were investigated in comparison with that with an equiaxed α structure in this study. In fretting fatigue of the Ti-4.5Al-3V-2Mo-2Fe alloy with a Widmanstätten α structure in a high cycle fatigue life region, and that with an equiaxed α structure in low and high cycle fatigue life regions, the fretting fatigue life does not change linearly with contact pressure, and the fretting fatigue life shows the minimum at a certain contact pressure. In a low cycle fretting fatigue region of the alloy with Widmanstätten α structure, the fretting fatigue life changes linearly with changing in contact pressure. At contact pressures over a certain value, fretting fatigue life of the alloy tends to become nearly constant in each fatigue life region. At relatively lower contact pressures, the main small crack in the alloy with equiaxed α structure tends to be formed at uneven wear damaged parts by fretting wear in the slip region in each fatigue life region. At relatively higher contact pressures, the main small crack in the alloy with equiaxed α structure tends to be formed at the boundary between slip and stick regions in each fatigue life region. The main small crack in the alloy with Widmanstätten α structure tends to be formed in the slip region in each fatigue life region.