Increasing the wear resistance of hip prostheses components using micro-nanostructured thin layers

Abstract

Evaluation of micro-nanostructured thin layers applicability for increasing the lifetime of rehabilitation systems, mainly hip prostheses, is the aim of the present research. This because, the final objective of the complete project is to improve the quality of human prostheses using micro-nanostructured thin layers. In order to realize these researches, 0.5, 1, and 1.5 µm thick thin layers of TiN and TiO2, were deposited on substrates made of materials currently used for hip prostheses – M30NW steel and CoCr – using physical deposition methods, respectively Cathodic Arc (CA), Direct Current (DC) sputtering and High-Power Impulse Magnetron Sputtering (HiPIMS). After tribological and nanoindentation tests, the 1.5 μm thick TiN and TiO2 thin layers deposited on the steel and CoCr substrates using the DC sputtering method presented superior mechanical properties. Functional characterization of a total hip prosthesis, that have had components coated with these thin layers presented an increased resistance to fatigue wear. After comparative analysis, the main conclusion of the realized researches was that TiN layers with a thickness of 1.5 μm have an increased resistance to fatigue wear in comparison with TiO2 layers, when both are deposited by DC sputtering on M30NW steel and CoCr substrates. It was observed that 1.5 μm thick TiN layers ensures a prolongation by 15% of the lifetime of femoral heads compared to those uncoated.