Effect of lattice defects on tribological behavior for high friction coefficient under TCP added PAO lubrication in nanostructured steels

Abstract

Synopsis: The effect of lattice defects on the tribological behavior for high friction coefficient under tricresyl phosphate (TCP) added poly-α-olefin (PAO) lubrication was investigated in the nanostructured steels produced by heavy plastic deformation processes. In the surface-nanostructured SUJ2 bearing steel, the tribological behavior with high friction coefficient was observed in the ball-on-disk tests in comparison with the non-deformed steel. In addition, the similar phenomenon was observed in the ultra-low carbon (ULC) steel with high-density of lattice defects (grain boundary, dislocation and so on). By increasing the density of lattice defects, higher friction coefficient was shown. The reason of the tribo-logical behavior with high friction coefficient seems that the compound film of Fe-O-P system formed in the ball-on-disk test was worn.