Wear-triggered self-repairing behavior of bionic textured AISI 4140 steel filled with multi-solid lubricants

The wear fatigue of slewing bearings at the contact areas of raceways (AISI 4140 steel (AS)) and rollers (AISI 52100 steel) seriously reduces the service life of equipment. AS-SnAgCu-TiC composites (AS-SACT) were prepared by filling multi-solid lubricants into surface biomimetic textures of AS to improve the wear resistance. Tribological properties were tested using a block-on-ring tribometer. The materials of block and ring were AS and AISI 52100 steel, respectively. Compared with that of AS, coefficient of friction of AS-SACT was decreased by 67.93%, and wear height was reduced by 42.19%. Wear triggered the diffusion of SnAgCu from the bionic textures to worn surface. The hard phase of nano-TiC was wrapped by a cluster of multi-layer lubricants to form spherical particles, which not only converted sliding to rolling contact, but also repaired pits and furrows on worn surface. Hence, AS-SACT with self-repairing behavior had excellent properties of antifriction and wear resistance. •Tribological properties of AISI 4140 steel were improved by texture and SnAgCu–TiC. •Average COF of AS-SnAgCu-TiC was 67.93% lower than that of AS (AISI 4140 steel). •Wear defects were filled with solid lubricants to produce self-repairing behavior. •Spherical particles transformed the frictional mode from sliding to rolling. •Nano-TiC particles wrapped by SnAgCu can promote wear defects to be filled.