Dresden 2014 – scientific programme

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MM: Fachverband Metall- und Materialphysik

MM 8: Topical Session: Nanomechanics of nanostructured materials and systems II - Thin films

MM 8.4: Talk

Monday, March 31, 2014, 12:45–13:00, BAR 205

Influence of the Film Thickness on Fragmentation, Adhesive Failure and Contact Damage of Diamond-Like Carbon (DLC) Coated Titanium Substrates — •Daniel Bernoulli¹, Andi Wyss¹, Kathrin Häfliger¹, Kerstin Thorwarth², Götz Thorwarth³, Roland Hauert², and Ralph Spolenak¹ — ¹ETH Zurich - Laboratory for Nanometallurgy, Department of Materials, Zurich, Switzerland — ²EMPA, Swiss Federal Laboratories for Materials Science and Research, Dübendorf, Switzerland — ³DePuy Synthes, Solothurn, Switzerland

Diamond-like carbon (DLC) coated friction pairs are well-known for their long durability and outstanding tribological behavior. However, wear and loose particles trapped between the friction pairs can lead to the appearance of high pressure on the DLC coating and may result in contact damage, fragmentation and adhesive failure. The influence of the DLC film thickness on these three effects is presented in this talk. The contact damage upon indentation was analyzed by finite element analysis and experimental studies. For thicker films circumferential and horizontal cracks are present in the DLC while for thin DLC films pronounced plastic deformation of the substrate occurs. The fragmentation analysis reveals that a very high DLC fracture strength can be achieved by keeping the DLC film thickness <1 μm and adhesive failure correlates with film thickness and the applied strain. For all three cases an optimal DLC film thickness is presented.