| Abstract: | A mechanical analog of a tribological system in the boundary friction mode is studied. A thermodynamic model is used to analyze
the first-order phase transition between liquidlike and solidlike structures of a lubricant. The time dependences of the friction
force, the relative velocity of the interacting surfaces, and the elastic component of the shear stresses appearing in the
lubricant are obtained. It is shown that, in the liquidlike state, the shear modulus of the lubricant and the elastic stresses
become zero. The intermittent (stick-slip) friction mode detected experimentally is described. It is shown that, as the lubricant
temperature increases, the frequency of phase transitions between the lubricant structural states decreases and the total
friction force and elastic stress amplitudes lower. When the temperature or the elastic strain exceeds the corresponding critical
value, the lubricant melts and a kinetic slip mode in which the elastic component of the friction force is zero takes place. |
