Investigation of the tribolgocal behaviour of microstructures for controlling the material flow in sheet-bulk metal forming

Sheet-bulk metal forming (SBMF) processes are characterized by a successive and/or simultaneous occurrence of different load conditions with regard to stress and strain states. These conditions significantly influence the material flow and thus the geometrical accuracy of the produced components. To improve the product quality a control of the material flow is required. A suitable approach is given by a local modification of the tribological conditions using surface modifications of tool or workpiece. To control the material flow, methods to adjust the friction are needed. Within the present study, microstructured workpiece surfaces to reduce the friction are investigated. The aim of the study is the determination of the tribological mechanisms of this kind of surface modifications. To identify the mechanisms a combined experimental and numerical approach was used. The use of such a combined approach revealed that the structure volume and the interaction between different types of structures significantly influence the friction reducing potential of microstructured workpiece surfaces.