The Relation Between Subsurface Stresses and Useful Wear Life in Sliding Contacts

Equations for quantifying the subsurface shear stress in dry point contact are utilized to obtain the value and location of the maximum subsurface shear stress. A series of experiments using a pin-on-disk tribometer is conducted on run-in specimens made of steel, brass, and aluminum, and the weight loss and wear rate of the specimen are measured. The results reveal a correlation between the depth of the maximum subsurface shear stress obtained from the model and the measured wear rate. It is shown that at the onset of failure, the friction coefficient suddenly increases. This increase affects the location of maximum subsurface shear stress by pushing it toward the surface and producing wear particles. SEM images of all three friction-pair tested reveal that the size of the wear particles is directly related to the applied load.