Slide burnishing versus deep rolling—a comparative analysis

This article presents outcomes from a comparative analysis involving three static burnishing processes: slide burnishing (SB), roller burnishing (RB), and deep rolling (DR). The treated material was 41Cr4 steel. The investigative methods used were fully coupled thermal-stress finite element (FE) simulations and natural experiments. Using one and the same magnitudes for the governing factors, the basic difference among the compared processes was the type of contact between the deforming element and the surface being burnished—sliding friction for SB and rolling contact for RB and DR. SB was implemented with a spherical-ended polycrystalline diamond whereas RB and DR were conducted using a single toroidal roller with the same magnitude for the radius of the toroid surface as that for the radius of the deforming diamond. The objects of comparison were in themselves processes and considered to be alterations in the thermodynamic systems’ states, as were the obtained surface integrities (SIs) of the treated specimens and their fatigue behaviors. It was established that three-quarters of the external work in SB converts into heat in the “deforming element–workpiece” contact area, which leads to the so-called softening effect in the surface layers. The comparison of the energy balances of the investigated processes clearly demonstrates the thermo-mechanical nature of the SB process, whereas the deforming processes in the RB and DR can be assumed to be purely mechanical. On the other hand, SB provides less roughness, significantly greater micro-hardness, larger-in-absolute-values compressive residual stresses, a more refined microstructure and, as a result, greater fatigue strength compared with RB and DR.