Medel F J, Puértolas J A
Department of Materials Science and Technology, CPS, I3A, ICMA, Universidad de Zaragoza, Zaragoza, Spain.
Proc Inst Mech Eng H. 2008 Aug;222(6):877-85. doi: 10.1243/09544119JEIM386.
Ion implantation may provide medical polyethylenes with excellent mechanical and tribological properties, helping to lower the risk of long-term osteolysis. Highly crosslinked and remelted polyethylenes, materials currently used as soft components in artificial joints, were implanted with N+ and He+ ions at different ion fluences. The mechanical and tribological properties under distilled water lubrication at body temperature were assessed after ion implantation by means of microhardness and pin-on-disc tests respectively. Thus, the influences of the ionic species and implantation dose on surface hardness, friction coefficient, and wear factor were fully characterized. Furthermore, the tribological behaviour was evaluated after an accelerated ageing protocol (120 degrees C for 36h). Ion implantation increased the surface hardness, as well as friction coefficients, and decreased the wear factors especially at the highest doses. Also, even though all artificially aged materials showed a worse wear behaviour, polyethylenes implanted with either N+ or He+ at the highest doses maintained a relatively good wear factor in comparison with the aged non-implanted material. The origins of these modifications are discussed according to the effects of ion implantation on the microstructure of the polymer.
离子注入可以赋予医用聚乙烯优异的机械和摩擦学性能，有助于降低长期骨溶解的风险。目前用作人工关节软部件的高度交联和重熔聚乙烯材料，以不同的离子通量注入N+和He+离子。离子注入后，分别通过显微硬度测试和销盘试验评估了在体温下蒸馏水润滑条件下的机械和摩擦学性能。由此，全面表征了离子种类和注入剂量对表面硬度、摩擦系数和磨损因子的影响。此外，在加速老化试验（120℃，36小时）后评估了摩擦学行为。离子注入提高了表面硬度以及摩擦系数，并降低了磨损因子，尤其是在最高剂量时。而且，尽管所有人工老化的材料都表现出更差的磨损行为，但与未注入离子的老化材料相比，以最高剂量注入N+或He+的聚乙烯仍保持相对良好的磨损因子。根据离子注入对聚合物微观结构的影响，讨论了这些改性的起源。
