Invited speaker

Some insights into the classical ball on disc test

by Pr. Enrico CIULLI

University of Pisa - Italy

Friction and wear behaviour of mechanical components is often investigated using the ball-on-disc apparatus. Tests are usually performed according to the ASTM G99 standard by applying a constant load. There are some aspects that should be taken into account for an appropriate use of the experimental results. In particular the effects of the curvature of the track and the contact pressure variation during running of the test due to ball and/or disc wear are investigated.

The hip, not so simple joint...

by Nicolas BONIN

Clinique de la Sauvegarde - France

Long time considered a problem-free joint, only requiring an arthroplasty when it reached an advanced state of arthritis, recent understanding of painful hip pathologies in athletes took off in the early 2000s with the finding of hip impingement.

If the description was at first simplistic, the better knowledge of the hip biomechanics confirms the complexity of this joint which evolves, according to its anatomy and the sport practiced, between instability and bony impingement.

New computer tools that allow a dynamic three-dimensional evaluation of the joint are now essential for the precise diagnosis of the dysfunction, and for the accuracy of the treatment.

While waiting for these tools to enter the operating room to support the surgeon in his therapeutic gesture, there is only one step.

 Insights into the solid lubrication mechanisms of graphite-phenolic resin coatings.

by Pr. Martin DIENWIEBEL

KIT - Karlsruhe Institute of Technology - Germany

Aiming to develop rolling element bearings that are lubricated by a solid lubricant, we investigated the friction and wear behavior of graphite-phenolic resin coatings as function of humidity using microtribometer experiments. We varied the graphite-binder concentration in order to find an optimum in friction and coating lifetime and studied the lubrication mechanisms in comparison to pure graphite.