Influence of different input parameters on the contact conditions determing the surface integrity of workpieces in an unguided vibratory finishing process

Abstract

The contact force and the relativevelocitybetween workpiece and abrasive media in a vibratory finishing have a strong effect on the material removal rate and the surface roughness of the machined workpieces. Both, the contact force as well as the relative velocity, are mainly influenced by the characteristics of the abrasive media type used as well as the geometry and the density of the workpieces. Furthermore, major influence factors on the contact conditions between the workpiece and abrasive media are the input parameters of the vibratory finishing machine, e.g. the mass distribution between the upper and the lower imbalance weights, the offset angle between the imbalance weights and the rotational speed. In order to determine the influence of the abrasive media and the workpiece characteristics as well as the different input parameters of the machine on the contact conditions, two measurement systems in the form of a camera-integrated workpiece and a workpiece with an integrated piezoelectric sensor have been used. The completely wireless construction of the measurement systems enabled the measurement of the contact force as well as the relative velocity without the influence of wires for data transfers and electrical power supply. The results have shown that the contact force as well as the relative velocityand therefore the surface integrity of the machined workpieces are mainly effected by the adjustments of the rotational speed and the size of the abrasive media.