The influence of sheet surface modification on tribological properties in the sheet strip drawing test

The tribological properties of sheet metal surfaces play a significant role in plastic forming processes, influencing the material's deformation, the value of technological forces, and the quality of the resulting products. One of the most important parameters describing the contact conditions between the tool and the material is the coefficient of friction, whose value depends, among other things, on surface topography, unit pressure, and lubrication conditions. Modifying the surface layer can change the nature of contact between mating surfaces, influencing the intensity of friction phenomena. The aim of the study was to determine the effect of selected sheet metal surface modification methods on the coefficient of friction determined in a strip drawing test.

The study was conducted using a tribotester with controlled pressure values. The sample surfaces were prepared in three variants: as-delivered, after sanding, and after sandblasting. Tribological tests were performed under dry friction conditions and with lubrication using S100 Plus oil for pressures of 3, 6, and 9 MPa.

Analysis of the results showed that for the as-received surface and after sanding, the friction coefficient increases with increasing pressure during dry friction, with the lowest values ​​obtained for the as-received sheet metal. Under lubrication conditions, both sanding and sandblasting led to a lower friction coefficient compared to the unmodified surface. The obtained results confirm that appropriate shaping of the surface topography can positively influence friction conditions in sheet metal forming processes, especially in the presence of a lubricant.