Wear characterization of Ti–6Al–4V under fretting–reciprocating sliding conditions

Wear affects life, vibrational characteristics, and dimensional stability of the components that slide against each other in small oscillatory movements. This study investigated the fretting–reciprocating wear behavior of a titanium alloy under cylinder-on-flat contact configuration (both Ti–6Al–4V) with bulk cyclic loading. Four series of tests were conducted to characterize the effects of sliding and loading parameters on the wear behavior. These were the relative slip, contact load, number of cycles, and bulk cyclic stress. The reciprocating wear produced “U-” and “W-”shaped (scar with multiple valleys) scars on the specimen as well as on the pad. Optical and scanning electron microscopy of the wear scars was conducted to study the wear mechanism(s). MATLAB-based computer programs were developed to determine the wear volume using the three-dimensional profilometry data, the product of contact load (P) and relative slip (δ), and the energy dissipated (Ed) per fretting cycle. Analysis of the experimental data showed that the cyclic stress increased the relative slip. The ratio of shear force to contact load (Q/P) increased with number of fretting cycles. The wear volume was proportional to the cumulative products of ΣPδn and the dissipated energy ΣEd. The microscopy of W-shaped scars showed that the valleys were covered by abrasive grooves, whiles the peaks showed signs of adhesive wear, thus suggesting that the wear was caused by both the adhesion and abrasion processes.