We describe herein how a quartz crystal microbalance (QCM) can be used to measure wetting behavior and sliding friction levels of adsorbed films and a brief summary of the status of the fundamental energy dissipative mechanisms that give rise to friction in these systems. The relation between sliding friction values, diffusion coefficients, and film lubricity is next described. Finally, as a sp...

In order to be suitable for tribological applications, polymeric materials, which can usually exhibit mechanical strength, lightness, ease of processing, versatility and low cost, together with acceptable thermal and environmental resistances, have to show good abrasion and wear resistance. This target is not easy to achieve, since the viscoelasticity of polymeric materials makes the analysis o...

The mechanical and tribological properties of electrospun fiber mats are of paramount importance to their utility in a large number of applications. In this work, mats of electrospun fibers of poly(hexamethylene adipamide) (PA 6,6) with average fiber diameter of 238 ± 22 nm are characterized for their crystal structure as well as their mechanical and tribological properties. Post-spin thermal a...

The menisci protect the articular cartilage by reducing contact pressure in the knee. To restore their function after injury, a new silk fibroin replacement scaffold was developed. To elucidate its tribological properties, friction of the implant was tested against cartilage and glass, where the latter is typically used in tribological cartilage studies. The silk scaffold exhibited a friction c...

It is proposed to use elastomeric composites as artificial joint bearing surfaces to increase their fluid film lubrication and therefore reduce the number of failures which have been attributed to wear mechanisms. The fluid generated between the surfaces supports part of the load and prevents direct contact of the bearing surfaces. In order to obtain optimum elastohydrodynamic lubrication, elas...

This paper reports on the effects of nitrogen dilution on the structure, bonding and tribological properties of nitrogendoped amorphous carbon films (a-C:H:N) deposited by r.f. glow discharge from CH4-N2 mixtures on silicon substrates. For different N2 fractions, film structure and chemical composition were examined using Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The mechan...

Observation of a tribo-induced transition from solid to liquidlike behavior is reported for a scanning tunneling microscope tip in sliding contact with an indium electrode of a quartz crystal microbalance (QCM). In particular, at a sufficiently high asperity sliding speed (about 1 m/s) and/or sample temperature, a change in the contact mechanics is observed that is consistent with melting in te...

A deterministic theory describing the behavior of an ultrathin lubricant film between two atomically-smooth solid surfaces is proposed. For the description of lubricant state the parameter of excess volume arising due to chaotization of solid medium structure in the course of melting is introduced. Thermodynamic and shear melting is described consistently. Dependences of friction force on tempe...

in this research, b4c-ni cermet coating was sprayed on the surface of 4130 steel from b4c and ni feed-stockpowders using high velocity oxy-fuel (hvof) method. in order to characterize the tribological behavior of thecoating, ball on disk wear tests were done at the ambient temperature and under the loads of 1, 3 and 5 n.phase analysis of the coating after spraying was studied by x-ray diffracto...