Guiming Mei. Impact of voltage on the electric sliding tribological properties of current collectors against overhead lines. Wear, 2021, 474: 203868.
https://doi.org/10.1016/j.wear.2021.203868

Fig. 4. Abrasion rate of collectors as a function of voltage: (a) V = 150 km/h, (b) Fn = 100 N.