Project IV – Mechanisms of nano-particle detachment

Contributors: G.Reiter, M.Brendlé

Wear is a common phenomena occurring quite systematically in dry sliding macro-contacts, and its control is one of the greatest economical challenges. On the macro-scale, friction and wear are strongly influenced by the debris remaining in the contact area and forming the so-called 3rd body. On all length scales, the mechanism of particle detachment depends very sensitively on environmental conditions and is still one of the less well understood tribological phenomena. Now, even for macro-contacts the size of the debris often lies in the nanometer range (10-30 nm). This was for instance shown by previous AFM studies of agglomerated debris formed during the friction and transfer of graphite.
The question, which arises, is whether a single process may form these particles or rather by the subsequent comminution of relatively larger particles. Since wear particles may also be produced in nano-contacts, provided the applied stresses exceed a given threshold value, it would be interesting to study the size of the debris which may be formed within a nano-contact, and how it will be influenced by environment conditions.
A collaboration with other laboratories, both on the theoretical as well as on the experimental side, is highly desirable.