The Micro-scale Deformation of the Contact Surfaces in Precision Positioning Mechanism

For the micro-nano positioning structure, the static friction existed in stick region will destroy the actuated efficiency and positioning accuracy hardly. It is important to describe the micro scale topography of the contact surface reasonably for the research of friction characteristic. After comparing some friction models, such as LuGre model, elastoplastic model, Maxwell-slip model and generalized Maxwell-slip model (GMS model), the GMS model is chosen to describe the micro scale topography of contact surface. Some experiments have been done to investigate the micro-scale deformation of contact surfaces in presliding region, the pure elastic deformation is validated between the contact surfaces, and the maximum size of pure elastic deformation has positive correlation with the normal pressure on the contact surface. After analyzing the friction force and the relative movement displacement between the two contact surfaces, a linear relationship has been found between them in some specific sections, and the size of these sections are associated with the normal pressure on the contact surfaces. This research content is valuable for the research of micro-scale topography of contact surfaces, and the deformation of asperities between the contact surfaces, and also the friction characteristics in presliding region.