4. Conclusion

The last example illustrates the benefits of nanotribology. It enables us to work on a single contact and simultaneously monitor dissipation and the state of the contact in real time. Elementary wear mechanisms can thus be identified and characterized. In a macroscopic contact, intrinsically multi-contact at asperity level, even if elementary mechanisms are triggered spontaneously in a delocalized manner in space and time, it's easy to imagine that couplings must be significant, correlating all events. This makes it very difficult to know who is responsible for what. Generally speaking, the challenge that remains is to make the link between what we learn in nanotribology and what we observe in tribology on macroscopic contacts. Nanotribology enables us to explore the many elementary mechanisms, essentially interfacial, that can occur in a single contact of well-controlled geometry. These...