Velocity dependence of nanoscale wear in atomic force microscopy

The velocity dependence of nanoscale wear is studied over a wide range of velocities up to 100mm∕s. High sliding velocities are achieved by modifying an existing setup with a custom calibrated piezostage. Pt-coated atomic force microscope probes are scanned against uncoated diamondlike carbon-coated Si wafers and with an overcoat of a lubricant film. The wear rate increases with logarithm of velocity up to a certain value and then levels off. A wear model is developed to explain the velocity dependence of nanoscale wear based on thermally activated atomic-scale stick slip and tribochemical wear.