Dresden 2014 – wissenschaftliches Programm

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MM: Fachverband Metall- und Materialphysik

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

MM 8.3: Vortrag

Montag, 31. März 2014, 12:30–12:45, BAR 205

Mechanical properties of reactively sputtered ceramic single and multilayer thin film structures for dental implants — •Daniel Muff and Ralph Spolenak — ETH Zurich, Laboratory for Nanometallurgy, Switzerland

Due to their inherent dark grey color, titanium dental implant screws can cause undesired darkening of the peri-implant mucosa [1]. Ceramic single and multilayer thin film structures have been developed to increase their reflectance based on interference phenomena.

Besides the esthetic function, the mechanical integrity of the coatings is crucial. As implants bend during chewing motions, coatings have to withstand compressive and, more critically, tensile strains. Therefore, in-situ tensile testing of the ceramic films on polyimide and titanium substrates has been carried out in optical and scanning electron microscopes in order to determine their fracture and delamination behavior.

It was found that the strain at onset of fragmentation decreases with increasing film thickness or number of layers. The crack distance saturates at around 10 times the film thickness and is slightly smaller for coatings on Ti than on polyimide which can be explained by the mismatch of the elastic constants of film and substrate [2]. While buckle formation was observed for thin films, thicker films showed severe delamination.

References: [1] SE Park, JD Da Silva, H-P Weber, S Ishikawa-Nagai (2007) Clinical Oral Implants Research 18: 569. [2] ZC Xia, JW Hutchinson (2000) Journal of the Mechanics and Physics of Solids 48: 1107.