Regulating tribofilm formation by harnessing hydrodynamic lubrication effects in double-sided periodic contact

The refined design of the surface textures is promising to address the issue of severe wear in advanced mechanical equipment. Through the comparative tests with different double-sided textured patterns under different loads, the largest reduction in friction coefficient of 10.94% was achieved at 50 MPa for circular double-sided textured surface compared to untextured surface, with also the largest reduction in wear depth. The possibility of double-sided textures overlapping should be avoided, which can improve the hydrodynamic lubrication effects. The lubricant provides the main loading capacity when the side texture is out of contact with the other side texture. The circular textures with gradually changing flow channels improve the loading capacity, reducing the pressure in the contact area. It reduces the removal rate of the tribofilm to form thicker tribofilms with more phosphate, sulfide, and sulfate. This reduces the mutual contact of the micro-asperities, thus providing effective wear protection. It can provide some insight into the matching design of double-sided textures under severe operating conditions.