Tool wear modelling for constant removal rate in two-bodies automated polishing

Abstract

Complex shapes such as medical implants or injection moulds require the use of super-finishing operations to minimise geometrical defects, down to mirror effect finish. These pre-polishing and polishing operations are still regularly performed manually by skilled workers. In spite of advantages in terms of repeatability, productivity and geometrical quality, automatic polishing methods are not widely used because they require systematic and significant developments. One of the main issues is the modification of the abrasive tool efficiency during the process. It evolves over time due to abrasive grains tearing and transfers onto the abrasive tool surface of workpiece microchips. Thus a model of tool wear is proposed and compensation strategies are elaborated to ensure a constant material removal rate on the surface. Compensations are performed by optimising the spindle speed and/or the feedrate along the tool path and are validated through experimental investigations.