Novel method for in-situ and simultaneous nanofriction and nanowear characterization of materials

Abstract

Nowadays, there is an increased need to know the nanotribological properties of protective coatings used in part devices operating under nano- and microcontact situations, e.g., hard disk drives, magnetic heads, microelectromechanical systems and microsensors, etc. Therefore, there is a demand for instruments and methods testing friction and wear at the nano- and microscales. In this work, the authors present a new methodology to measure simultaneously the friction, and wear of a surface. The authors have designed an experiment, where a probe is permanently scanning a 10 μm track in a reciprocal movement. Different loads are applied in order to obtain the topographic information which is used to calculate the wear rate and roughness evolution. Force lateral sensors register simultaneously the friction force variations. The experimental input data are information vectors that contain: load (μN), friction force (μN), vertical Z displacement (nm), lateral X displacement (nm), and time (s). The data are processed using a simple program running in MathLab® which eliminates the thermal drift. The software output gives the resulting friction coefficient, track roughness, and wear rate as a function of the running cycles of the probe. The new method builds a novel bridge to relate tribological mechanisms at different scales.