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2010
Conference Paper
Titel
DLC-coated CoCrMo steel for use in medical implants - wear and corrosion resistance influence of different surface finishing techniques
Abstract
Cobalt-based alloys have been widely used in implant components, especially in orthopaedic implants. The biocompatibility of CoCrMo alloy is related closely to this material's excellent corrosion resistance, imparted by a thin passive chromium oxide layer with some minor contributions from Co and Mo oxides. The oxide film on CoCrMo alloy inhibits the dissolution of metal ions but is not always stable in the human body. There is a general agreement that corrosion is a serious problem for medical metallic materials. For joint replacements, they are exposed to tribological contacts and load so their performance (long-term durability) relies on both their corrosion and wear resistance. Diamond like carbon (DLC), with its extreme smoothness, hardness, low coefficient of friction, and biocompatibility is an excellent candidate to serve as a tribology-enhancing and corrosion-protective functional coating. In this study we have characterized the complex wear - corrosion resistance of the CoCrMo / DLC system. The wear-corrosion effects were investigated in a simulated body fluid under the simultaneous action of electrochemical corrosion and mechanical wear. The effects of the corrosion and wear of the CoCrMo/DLC systems are discussed.