Fig. 3: Scanning Electron Microscopy images of wear tracks and counter bodies taken after microtribometer experiments at different pressure and humidity values.

a ≤5% RH (dry pressurized air) at 50 MPa, b ≤5% RH (dry pressurized air) at 1 GPa, c 24% RH at 1 GPa, and d 45% RH at 1 GPa. The white ovals in a, b, c represent regions of interest for a preparation of lamellae that are analyzed in consecutive TEM characterization.