SURFACE CHARACTERIZATION WITH REGARD TO THE TRIBOLOGICAL BEHAVIOUR OF SHEET METAL IN FORMING PROCESSES

U. Popp; T. Neudecker; U. Engel; M. Geiger

University of Erlangen-Nuremberg

Friction in sheet metal forming significantly depends on the surface topographies of the tool and the workpiece. Standardized 2D-roughness-parameters are not able to characterize deterministic textures clearly, nor do they give any reliable information about the tribological properties of the topography. Using standard sheet metal topographies, it is shown that new 3D-parameters, especially the maximum ratio and the volume of closed lubricant pockets, which are derived from a mechanical-rheological model, are useful to characterize the tribological behaviour of textured sheet metal in deep drawing. Both, steel and automobile manufacturer can benefit from these 3D-parameters to stabilize their production processes.

Keywords : sheet metal forming, tribology, surface characterization