Arthritis is a leading cause of disability, and when nonoperative methods have failed, a prosthetic implant is a cost-effective and clinically successful treatment. Metal-on-metal replacements are an attractive implant technology, a lower-wear alternative to metal-on-polyethylene devices. Relatively little is known about how sliding occurs in these implants, except that proteins play a critical...

A special phonomenon of self-lubrication compensation named hole-wedge effect was found in a bionic porous friction pair, meanwhile the origin and regularity of this effect and its tribological behaviors were discussed in this paper. The process of self-circulating compensation of lubrication was modeled, and taking ferrofluid as lubricant a series of experiments were designed and done. Researc...

The importance of friction and wear control cannot be over emphasized for economic reasons and longterm reliability. The savings can be substantial, and these savings can be obtained without the deployment of investment. Tribology is crucial to modern machinery which uses sliding and rolling surfaces. This article describes the tribological behavior analysis for the conventional materials i.e. ...

In this paper, an observation on the toe pad of a newt was carried out. It was found that the pad surface is covered with an array of polygonal cells separated by channels, similar to those of a tree frog's pad. With this micro-structure, a newt can move on wet and smooth surfaces without slipping. Inspired by the surface structure of newt toe pads, elastic micro-patterned surfaces were fabrica...

Artificial articular joints present an interesting, and difficult, tribological problem. These bearing contacts undergo complex transient loading and multi axes kinematic cycles, over extremely long periods of time (>10 years). Despite extensive research, wear of the bearing surfaces, particularly metal-metal hips, remains a major problem. Comparatively little is known about the prevailing lubr...

Eight titanium complex greases (i.e., benzoic acid/stearic acid and sebacic acid/stearic acid titanium complex greases, and greases containing PTFE, or nanotitanium dioxide, or nano-silicon dioxide) were synthesized using 3-L reaction vessel. Their physical characteristics were characterized and their tribological properties were evaluated by using a four-ball tester. Chemical compositions of t...

Multialkylated cyclopentanes (MACs), a class of synthetic hydrocarbon fluid have attracted intensive interest as possible space lubricants due to a series of unique physical and chemical properties. Here, we used graphene with high mechanical strength and chemical inertness as lubricant additive to explore its potential for space application. The effects of space irradiation on graphene and the...

>> The author’s hear elt gra tude goes to Sandra Guadalupe (TIC), Stefano Mischler (TIC), Marijana Mionic (LTP), Nicolas Xanthopoulos (CIME), Véronique Michaud (LTC), Ma hieu Soutrenon (LTC) and all members of the RUAG Space staff. Aknowledgements Results >> Ionic liquids (IL) are organic salts that remain liquid at room temperature and below. Besides having negligible vapour pressure, good ele...

INTRODUCTION Polytetrafluoroethylene (PTFE), a highly crystalline polymer with melting temperature around 330°C, possesses unique properties. Chemically inert, it has high chemical and heat resistance with upper service temperature around 260°C. Since its invention it has found limited applications especially as an additive because of its high molecular weight and inert surface. However, by mid...

Surface texturing has been shown to be an effective modification approach for improving tribological performance. This study examined the friction reduction effect generated by square dimples of different sizes and geometries. Dimples were fabricated on the surface of ASP2023 steel plates using femtosecond laser-assisted surface texturing techniques, and reciprocating sliding line contact tests...