Effect of slide burnishing basic parameters on fatigue performance of 2024‐Т3 high‐strength aluminium alloy

Abstract

AbstractThe effect of slide burnishing (SB) on the high‐cycle fatigue (HCF) performance of 2024‐T3 high‐strength aluminium alloy has been studied. After SB with optimum basic process parameters under ‘minimum roughness’ criterion, the 107 cycle fatigue strength increases with 25% – from 180 to 225 MPa, fatigue life is increased more than 50 times, and the roughness obtained reaches up to Ra = 0.05 μm. Further, various combinations of burnishing force and deforming element radius have been applied to reach maximum HCF performance despite roughness obtained. It has been established that with the optimum combination under ‘maximum HCF performance’ criterion, 107 cycle fatigue strength increases with 44% – from 180 to 260 MPa as the roughness obtained is Ra = 0.25 μm. This significant enhancement in the HCF performance is due to introduced beneficial residual compressive stresses. They shift the fatigue crack initiation site from surface to subsurface layers and, as a result, the nucleation and propagation of the first‐mode fatigue cracks are retarded. In order to establish the fatigue limit (based on 2 × 108 cycles), a combined approach, based on limited Wöhler's curve and Locati's method, has been applied. The fatigue limit of 2024‐T3 high‐strength aluminium alloy can be increased up to 250 MPa using SB with optimal basic parameters under ‘maximum HCF performance’ criterion.