Friction is a key phenomenon in applied physics, whose origin has been studied
for centuries. Until now, it has been understood that mechanical
wear-resistance and fluid lubrication affect friction, but the fundamental
origin of sliding friction has been unknown. Dr. Lasse Makkonen, Principal
Scientist at VTT Technical Research Centre of Finland, has now presented an
explanation for the origin of sliding friction between solid objects.
According to his theory, the amount of friction depends on the surface energy
of the materials in question.
Friction has a substantial effect on many everyday phenomena, such as energy
consumption. Makkonen's model is the first to enable quantitative calculation
of the friction coefficient of materials.
Makkonen's theory, the amount of friction is related to the material's surface
energy. Friction originates in nanoscale contacts, as the result of new
surface formation. The theory explains the generation of frictional force and
frictional heating in dry contact. It can be applied in calculating the
friction coefficient of various material combinations. The model also enables
the manipulation of friction by selecting certain surface materials or
materials used in lubrication layers, on the basis of the surface energy
Makkonen’s theory on sliding friction was
published in the journal AIP Advances of the American Institute of Physics.
The research was funded by the Academy of Finland and the Jenny and Antti
Link to article: A
thermodynamic model of sliding friction