Wear experiments have shown that when the applied normal stress exceeds a critical value, a transition occurs from the regime of mild wear to that of adhesive wear. As a result, the wear rate of particle-reinforced aluminium composites increases by a hundred-fold. Based on dislocation and delamination theories, a criterion is proposed for determining the critical transition load, and a quantita...

Electro Discharge Machining (EDM) is a noticeable machining practice among created unconventional machining procedures for intricate, complex profiles in "hard to machine" materials, similar to heat-treated steels, composites, superalloys, ceramics, composites, carbides, and so on. In EDM, the material expulsion of the cathode is accomplished through precise controlled electric discharge (the s...

In laboratory tests, the ultra-high molecular weight polyethylene used for the acetabular cups of Charnley hip prostheses has a very low wear rate against steel. In the body radiographic measurements indicate that the polyethylene wears more rapidly. In order to investigate this higher wear rate, the sockets of acetabular cups removed at post-mortem have been examined using optical and electron...

The effect of kinematics, loading and centre of rotation on the wear of an unconstrained total disc replacement have been investigated using the ISO 18192-1 standard test as a baseline. Mean volumetric wear rate and surface morphological effects were reported. Changing the phasing of the flexions to create a low (but finite) amount of crossing path motion at the bearing surfaces resulted in a s...

Introduction. Unicompartmental arthroplasty of the knee in patients with isolated medial osteoarthritis gives good results, but survival is inferior to that of total knee prosthesis. Knees may fail because positioning of the prosthesis has been suboptimal. The aim of this study was to investigate the influence of the tibial slope on the rate of wear of a medial fixed-bearing unicompartmental kn...

Poly methyl methacrylate (PMMA) is one of the most widely accepted biomaterial in prosthetic dentistry due to its acceptable advantages. However the conventional PMMA used are far from being ideal because of their inferior mechanical properties. So the present study is to determine the Vickers Hardness and specific wear rate of the silane treated E glass fiber reinforced PMMA. Vickers Hardness ...

Simultaneous measurements of the curves for wear versus distance, wear rate versus distance, and coefficient of friction versus distance were performed in situ to distinguish the transition from severe running-in wear to mild wear. The effects of the initial surface roughness on the severe running-in wear volume were investigated. Disk-on-plate friction and wear tests were carried out with SUS3...

It is generally known that the friction and wear between polymers and polished steel surfaces has a special character, the behaviour to friction and wear of a certain polymer might not be valid for a d ifferent polymer, moreover in dry friction conditions. In this paper, the reaction to wear of certain polymers with short glass fibres (polyamide + 20% glass fibres, polyamide + 30% glass fibres ...

.................................................................................................................... iv 1. Introduction .................................................................................................................. 1 2. Theory/Methodology for Wear in Prosthetic Implants ................................................ 3 2.1 Wear Mechanisms ..........

BACKGROUND The low wear rates of crosslinked polyethylenes provide the potential to use larger diameters to resist dislocation. However, this requires the use of thinner liners in the acetabular component, with concern that higher contact stresses will increase wear, offsetting the benefits of the crosslinking. QUESTIONS/PURPOSES We asked the following questions: Is the wear of conventional a...