We retrieved 159 femoral heads at revision surgery to determine changes in surface configuration. Macroscopic wear of the head was observed in three bipolar hip prostheses as a result of three-body wear. There was a considerable change in surface roughness in the internal articulation of bipolar hip prostheses. Roughness in alumina heads was almost the same as that in new cobalt-chromium heads....

Laboratory wear testing of ultra high molecular weight polyethylene from 12 Charnley acetabular cups, removed after periods of up to 17.5 years showed that the large patient-to-patient variations in clinical penetration rate cannot be explained by batch-to-batch variation in the wear resistance of the material. Nor was there any evidence of a time-dependent degradation in wear resistance of the...

Cr-Ni coatings with the mass ratios of 17% Cr-83% Ni, 20% Cr-80% Ni and 24% Cr-76% Ni were fabricated on H13 hot work mould steel using a laser cladding (LC). The surface-interface morphologies, chemical elements, surface roughness and phase composition of the obtained Cr-Ni coatings were analysed using a scanning electron microscope (SEM), energy disperse spectroscopy (EDS), atomic force micro...

Measurement uncertainties are vital to discussions of differences in measured values, yet they scarcely accompany discussions of wear and wear rates in the tribology literature. In this methods article, approaches to calculate uncertainties in single-point and steady-state wear rates are presented. The analysis includes analytical treatments of uncertainties for typical macroscopic tribology in...

Introduction: Wear of ultra-high molecular weight polyethylene (UHMWPE) is a major factor that affects longevity of the total joint replacement. In total hips (THR), cross-linking of polyethylene has been shown to be highly effective in reducing wear both clinically and experimentally [1-3]. Also, in TKR, Schmidig et al. [4] showed a 90% reduction of wear rate in 10 Mrad compared to 3 Mrad tibi...

The wear behaviour of total knee arthroplasty (TKA) is dominated by two wear mechanisms: the abrasive wear and the delamination of the gliding components, where the second is strongly linked to aging processes and stress concentration in the material. The addition of vitamin E to the bulk material is a potential way to reduce the aging processes. This study evaluates the wear behaviour and dela...

Despite the merits of glass ionomer cements (GICs), they suffer from weak mechanical properties such as low wear resistance. In this study, the mechanical properties of GICs after incorporating chitosan and nano-hydroxyapatite was investigated. The samples were prepared in four groups, including non-modified GIGs (NMGIC, n = 5), chitosan incorporated GICs (CHGIC, n = 5), nano-hydroxyapatite inc...

In electrolytic in-process dressing (ELID), a metal-bonded grinding wheel is dressed as a result of anodic dissolution. In this paper we describe experiments to evaluate the potential for ELID on bronze wheels in fixed-load grinding applications. A constant-force grinding apparatus was used to determine appropriate ELID conditions for a 10-20 \xm bronze bonded diamond grinding wheel used to mac...

Recent experimental research indicates that superelastic shape memory alloy nickel–titanium (NiTi) is superior to stainless steel against wear and could be applied in tribological engineering. It is believed that the super wear resistance of shape memory alloys is mainly due to the recovery of the superelastic deformation. Our recent wear study indicates that wear rate is very sensitive to the ...

Wear particle-induced biological responses are the major factors resulting in the loosening and then failure of total joint arthroplasties. It is feasible to improve the lubrication and reduce the wear of artificial joint system. Polyetheretherketone (PEEK) is considered as a potential bearing material due to its mechanical characteristics of resistance to fatigue strain. The PEEK wear particle...