title: The composition of tribofilms produced on metal-on-metal hip bearings.
abstract: Following wear testing in a hip simulator, the bearing surfaces of 36 mm metal on metal total hip replacements showed the formation of tribochemical layers. These layers were investigated in a transmission electron microscope, and analysis was performed using electron energy loss spectroscopy, energy dispersive x-rays and selected area electron diffraction. The tribofilm formed at the edge of the wear scar was 100 s of nanometres thick and contained cobalt sulphide particles embedded within. The film itself was rich in carbon, and appeared to contain no long range graphitic ordering when analysed with electron energy loss spectroscopy, and the spectra gathered from the tribofilm closely resembled those collected from amorphous carbon. The location at which the most substantial tribological layers formed may be explained by the formation of a blunt wedge at the edge of the wear scar following conformal changes to the bearing surfaces.
authors: Institute of Engineering Thermofluids Surfaces and Interfaces, Department of Mechanical Engineering, University of Leeds, Leeds, United Kingdom. Electronic address: hesketh.james@yahoo.com.
authors: James
authors: J
authors: Hesketh
authors: Leeds Electron Microscopy and Spectroscopy Centre, School of Process Environmental and Materials Engineering, University of Leeds, Leeds, United Kingdom.
authors: Michael
authors: M
authors: Ward
authors: Institute of Engineering Thermofluids Surfaces and Interfaces, Department of Mechanical Engineering, University of Leeds, Leeds, United Kingdom.
authors: Duncan
authors: D
authors: Dowson
authors: Institute of Engineering Thermofluids Surfaces and Interfaces, Department of Mechanical Engineering, University of Leeds, Leeds, United Kingdom.
authors: Anne
authors: A
authors: Neville
mesh_terms: D019644:Arthroplasty, Replacement, Hip; D018441:Biofilms; D006801:Humans; D013057:Spectrum Analysis / Q000379:methods
keywords: Graphitisation; Hip replacement; Transmission electron microscopy; Tribology