Effects of Vibratory Finishing on Residual Stress Profiles and Gear Flank Topography

The rising demand for larger power density in geared transmissions for electromobility and wind turbines has required precise control of the surface integrity properties. Advanced finishing processes can mitigate gear tooth failures but, without proper control, can also generate undesirable effects to negatively impact the components’ lifetime. This study investigates vibratory finishing (VF), a chemo-mechanical process, with respect to the induction of flank deviations on gears and the modification of residual stress via localized plastic deformation. X-ray diffraction assessment was conducted on surface and near-surface via incremental electrolytic polishing, enabling comprehensive depth profiling of stress distribution, whereas flank deviations were measured using tactile gear metrology procedures. The VF parameters of processing time and vibration intensity were correlated with the geometry of flank deviations and the resulting residual stress state. The results of this investigation elucidate the effects of the chemo-mechanical mechanisms of VF on residual stress and flank topography evolution, contributing to optimized surface integrity in high-performance gears.