Variations of Minimum Contact Areas on Slipping Range using Micro-Glass Spheres

Abstract

The problems of contact, joint and connection play important roles in every field of industry. Some micro-mechanical and electronic devices have elements that create friction against each other while in contact with one another all the time. Even though a small normal load is applied on the movement or behavior, the influence of the interaction between contact surfaces in all fields of industry cannot be ignored. In this study, how contact areas are varied in the slipping range between glass substrate and micro-glass spheres with varied diameters was investigated. In order to study the variations of contact areas, micro-glass spheres (dry borosilicate glass spheres) with different diameters (D=10µm, D=20µm) were glued to stainless steel-cantilevers (spring constant k=577N/m). The experiments were performed in various normal applied loads using AFM (Atomic force microscope) and variations between contact areas were simulated using the FEM (Finite Element Method). The variations on contact areas were compared using the results of the experiment using AFM and FE analyses in the contacted range for slipping of each micro-glass sphere. In addition to that, these were considered to be based on the wear volume and roughness as parameters due to their variations. From the results of the experiment, the contact area by the surface forces is dominated by increases and decreases of the wear volume due to the contact pressure force. Also, the influence of the deformation of the contact area due to contact pressure force cannot be ignored.

Keywords

• contact area
• stainless steel-cantilever
• micro-glass sphere
• afm (atomic force microscope)
• fem (finite element method)