Friction and wear of the LiF single crystals in unidirectional and bidirectional motion has been studied. The friction coefficient and wear are found to be higher under unidirectional motion. The dislocation structure and hardness of surface layers has been analyzed after friction. An anihilation of the dislocations and a decrease the hardness of surface layers under bidirectional motion confirm the role of the Bauschinger`s effect under friction. Friction and wear of the LiF single crystals is determined not only by the Bauschinger`s effect but by redistribution of the contact spots due to the adhesion of wear particles to rubbing surface and ploughing. This experiment demonstrates again a similarity in the behavior of LiF single crystals with the metals and a possibility to simple analysis of the dislocation interaction and damage development.
