Effect of Nitrogen Ion Irradiation on the Nanotribological and Surface Mechanical Properties of Ultra-High Molecular Weight Polyethylene

L FASCE; CURA, J.; MARIELA DEL GROSSO; GERARDO GARCÍA BERMÚDEZ; FRONTINI, PATRICIA

SURFACE AND COATINGS TECHNOLOGY

ELSEVIER SCIENCE SA

Año: 2010 vol. 204 p. 3887 - 3894

0257-8972

Generation of wear debris is the principal obstacle limiting the durability of ultra-high molecular weightpolyethylene (UHMWPE) in biomedical applications. Aiming to enhance UHMWPE wear resistance, surfacemodificationwith swift heavy ion irradiation (SHI) appears as a potential and attractivemethodology. Contrary toion implantation techniques, the swift heavy ions range can reach tens to hundreds microns and its extremelyhigh linear energy is able to induce effective chemical modifications using low fluence values. Nano-wearperformance and surface mechanical properties of samples of pristine and SHI irradiated (using N2+ ions at33MeV and a fluence of 1×1012 ions/cm2) were characterized by depth sensing indentation (DSI) and scanningprobe microscopy (SPM). It turned out that modifications induced by irradiation at the surface layers weresuccessful to reduce nano-wear volume and creep deformation. These improvements were related to beneficialchanges in hardness, elastic modulus, hardness to elastic modulus ratio and friction coefficient