A friction mechanism for surface texturing under dry/mixed lubrication conditions based on the sublinear dependence of friction on load

Based on the material property exhibiting a sublinear dependence of friction on load, a new mechanism of texturing for friction reduction has been identified and explored. In this, the nominal contact area is reduced by textures, the load of the non-concave area thus increases, and the friction coefficient is reduced by the sublinear dependence. Non-textured and textured samples were tested by a reciprocating tribometer to obtain the friction coefficient between polytetrafluoroethylene (PTFE) and steel. An empirical equation for the sublinear dependence was found, and used in a numerical mixed lubrication model to evaluate the mechanism. The results show that this mechanism explains well for the friction reduction of textured surface in dry conditions, and is still beneficial under mixed lubrication.