Promotion Dr. Hsu am 14.02.2022

Promotion Dr. Hsu am 14.02.2022, Titel und Abstract:

Enhance ZDDP Tribofilm Growth and Fatigue Lifetime of Rolling Bearings by Laser Surface Texturing
Laser surface texturing (LST) is a surface engineering method for improving frictional, thus
contributing to an increase in energy efficiency. However, not many studies have carried out
research of LST in the boundary lubrication regime, likely due to concerns of higher contact
stresses. This study aims to improve the fatigue lifetime of rolling bearings in the boundary
lubrication by LST combined with ZDDP-added lubrication. Firstly, the antiwear tribofilm was
characterized. The composition of the tribofilm and the difference between the blue- and the
brown-colored region was revealed. Secondly, the LST patterns were verified to reduce wear
due to the capacity of lubricant storage and the enhanced growth of ZDDP tribofilm. The
pressure distribution on the textured surface was calculated by a contact simulation, and the
increase of normal stress led to a promotion of the tribofilm. Finally, the rolling bearings with
the LST patterns demonstrated an increase in fatigue life