FOROB II

BAVARIAN JOINT RESEARCH PROGRAM FOR SURFACE TECHNOLOGY

I.7 Subject adapted structuring of surfaces

The surface topography of work piece and tool forms a major influence coefficient in the tribological system "forming process". The aimed setting of a micro topography on surfaces for cold forging adapted to the subject comprises a big potential for reduction of friction and the amount of lubricant. Whilst the structuring of tool steels due to the higher wearing can be effective only for a restricted tool life quantity, particularly the combination of of micro topography with PVD- or CVD-hard material coating promises a durable effect because of the increased wearing resistance. With the excimer laser a multifunctional tool is at disposal at the same time for structuring ceramic and metallic surfaces using the mask projection process.

Aim of the enterprise is the aimed micro structuring of the surface of hard material deposited tools for cold forging for obtaining improved adhesion and distribution of the lubricant, lower friction resp. forging forces and hence minimised-amount lubrication.

The task is firstly to acquire the necessary working parameters und their effects on surface topography of steel specimens before and after coating with hard material. Suchlike structured specimens are to be characterised by tribological basic experiments (eg strain-twist-experiment) regarding their wearing and friction properties. Finally promising micro structurings on extruding tools are to be checked in terms of their applicability in tool life quantity tests at the industrial partners.