Abstract
This study examines the impact of standard laser surface texturing on the tribological behavior of a conformal journal bearing with a large radial clearance. A common dimple pattern was applied to the shaft, and friction and lubricant film formation were evaluated across a wide range of speeds and loads using advanced optical diagnostics. Contrary to expectations from prior studies on non-conformal contacts, the textured surface consistently exhibited higher friction compared to the smooth reference. The strongest effects were observed in the mixed lubrication regime, where friction increased by up to 100%, and the transition to full-film lubrication was significantly delayed. High-resolution interferometry and fluorescence imaging revealed that dimples acted as lubricant sinks, locally starving the film; no cavitation was observed within or downstream of dimples. Additionally, the steep dimple geometry inhibited elastic deformation, contributing to persistent film thinning. These findings suggest that standard texturing strategies may not be suitable for conformal contacts with transitional lubrication behavior. The study highlights the importance of tailoring texture parameters to specific operating conditions and demonstrates the value of optical diagnostics in uncovering failure mechanisms in textured bearing systems.
