Laser Interference Patterning of Steel Surfaces - Influence on the Frictional Performance under Dry and Lubricated Sliding Conditions

For many years already, a lot of research groups try to shed light on the origin of friction and to enhance the tribological performance of rubbing surfaces. In this context, the ability to tailor the tribological properties on different scales is of utmost importance. In this work, laser interference patterning is used to produce well-defined surface topographies with line- and cross-like patterns in order to modify the tribological performance under dry and lubricated conditions. Under dry conditions, the frictional behavior of line-like patterned surfaces having a periodicity of 9 μm are investigated using a ball-on-disk tribometer in linear reciprocating sliding mode as a function of the normal load and the relative alignment. Regarding mixed lubrication, the oil film lifetime of cross-like patterns (periodicity of 9 μm) is evaluated using a ball-on-disk tribometer (normal load of 5 N and sliding velocity of 5 cm/s) in rotational sliding mode. The experiments under dry friction demonstrate a significant friction reduction for the line-like surface patterned surfaces, independent on the respective alignment. Dependent on the used normal load, differences in the frictional behavior are observed. For the cross-like patterns under mixed lubrication, an increase of the oil film lifetime by a factor of 56 is achieved