Markus Prieske¹, Annika Bohlen¹, Frank Vollertsen¹; ¹BIAS - Bremer Institut für angewandte Strahltechnik GmbH

For economic and environmental reasons, dry forming is of increasing interest due to the shortening of process chains, cost savings and reduction of environmental pollution. The aim of these investigations is to examine to what extent CVD-diamond coatings are suitable for the dry forming of aluminum alloy AlMg4.5Mn and to identify the surface topology requirements for a low friction coefficient and low wear. Nine different surface topologies of CVD-diamond coatings were tested in an oscillating ball-on-plate tribometer test against aluminum balls with a Hertzian contact stress of 760 MPa and 99,900 cycles. It could be concluded, that the peak material volume Vmp of the diamond coating is the most important factor to achieve a low abrasion of aluminum as well as a low friction coefficient against the aluminum. The Vmp should be smaller than 0.04 ml/m². Microcrystalline CVD-diamond with a post-treated surface has great potential for dry forming of aluminum.