Effects of modulation on friction during deformation processing

Abstract

Friction causes tool wear and increases redundant work during the deformation processing of metals and alloys. A technique involving the application of a controlled vibration on the tool or the work material has been found successful in machining operations. As a step towards the application of modulation to these other processes, a setup for the evaluation of frictional phenomena in indentation and compression between flats is developed. The setup is used to apply a controlled vibration (modulation) of low frequency on the work material during wedge indentation. The effects of this modulation on friction are observed indirectly through force measurements and characterization of microstructural flow patterns. It is found that the modulation enhances lubricant penetration into the tool-work material interface, thereby reducing the severity of the friction arising from the indentation action. The findings will inform the design of modulation systems applicable to a range of deformation processes.