Wear Behavior of Laser‐Patterned Piston Rings in Squeeze Film Dampers

Abstract

Machine components experience large tribological stresses during their lifetime. Due to the kinematics and the applied load, many of these components work under mixed or boundary lubrication conditions, with direct contact of both rubbing surfaces. Wear, thus plays a significant role in these two lubrication regimes, determining component life time. Laser surface patterning (LSP) can produce a well‐defined surface topography in order to improve the tribological properties under boundary and mixed lubrication, including reduced wear. In this research work, the piston rings (PRs) of a squeeze film damper (SFD, stainless steel MSRR 6503) are patterned with a dot‐like surface structure (4 μm spacing and ca. 1 μm depth) produced by three‐beam laser interference from a solid state Nd:YAG laser with a pulse duration of 10 ns and wavelength of 355 nm. The wear behavior of these laser‐patterned PRs is compared to that of conventional ground PRs. The tribological tests are performed on a special test rig for SFDs. The tested surfaces are then analyzed by white light interferometry in order to study the underlying wear mechanism and to estimate the corresponding wear volume. This analysis demonstrates an 85% reduction in the wear volume of the laser‐patterned PRs. The designed surface topography can store wear particles in the topographic minima, removing them from the contact zone, thus reducing the amount of abrasive wear and the wear volume.