A Study on the Tribological Behavior of Surface Texturing on Babbitt Alloy under Mixed or Starved Lubrication

Abstract

Aiming at improving the tribological performances of sliding bearings in mixed or starved lubrication regime, textures in square and linear radiating arrays are ablated on the surface of Babbitt alloy disks by laser radiation. Series of pin-on-disk wear tests and computational fluid dynamics (CFD) analysis are conducted to investigate the influence of distribution and geometry of the textures under various operating conditions. Results suggest that surface texturing suitably interacts with the material properties of Babbitt metal favorably improving its tribological performance. Friction coefficients of the disks with textures arrayed in square are generally much lower and more stable as compared to their counterparts with textures arrayed in linear radiation. Also, textures arrayed in a square with an area density of 8.6 % allow the lowest friction coefficient, as low as 0.015, to be achievable. Theoretical analysis sheds the light that proper texture arrangements tend to generate favorable distribution of micro-hydrodynamic pressure to improve the tribological performance of Babbitt alloy significantly.