Surface treatment on an implant cobalt alloy for high biocompatibility and wear resistance

The surface chemical composition of an implant cobalt alloy (Biodur) was modified, producing relevant tantalum enrichment. Tantalum was chosen because of its low toxicity and high corrosion resistance. The chemical composition, morphology, roughness, crystallographic structure and wettability of the surface, as well as the interface of the modified layer with the substrate, were characterized. The mechanical behavior of the modified materials was investigated by scratch and pin-on-disc wear tests. The metal ion release of the modified surfaces was measured by in vitro experiments after wear tests.