Wear kinetics of Ti–6Al–4V under constant and variable fretting sliding conditions

Fretting is defined as a small displacement oscillatory motion between two solids in contact. Depending on the loading conditions (displacement amplitude, normal force, …), fretting may cause damage by wear induced by debris formation and ejection. Predicting wear kinetics under fretting conditions is of great interest for industrial applications. For the studied titanium alloy Ti–6Al–4V, fretting conditions have been reproduced through a simple cylinder/plane contact. The introduction of a modified energy wear concept allows the rationalization through a single variable the relative impact of the pressure, sliding amplitude and number of fretting cycles. It is shown and modeled that the wear evolution, quantified through a unique wear parameter, can be normalized on a single wear master curve. Afterwards, this aspect is deepened by studying complex fretting loading conditions during a test. The stability of the model is then demonstrated by applying variable sliding conditions. One major advantage of this approach is the cumulative property of the introduced wear parameter, whatever the amplitude sequences and cycles distribution of the imposed displacement amplitudes.