Identification of conditions for nanostructured burnishing and subsurface shear instability

Numerical as well as physical modeling of nanostructuring burnishing has been carried out to find out the process parameter limiting levels, which serve both to provide appropriate surface quality and positive deformation-induced structural modification of the subsurface layers as well as to avoid shear instability in the subsurface layers of burnished metal. The effects of load, burnishing speed, tool tip material, tool pass number and tribological transfer on the burnished surface roughness have been elucidated by the example of quenched and tempered steel 20X (EN 20Cr4). It was shown that overloading results in quasi-viscous flow of the subsurface material, deterioration of the surface and ruining the positive effect of nanostructuring burnishing