What can micromechanics tell us about the surface integrity of shot-peened materials?

J. A. Robles-Linares; G. G. Luna; A. la Monaca; Z. Liao; M. C. Hardy

CIRP Annals (2023)

Standard techniques for assessing shot peening include XRD and EBSD for measuring residual stresses and severe deformation beneath the surface; however, these techniques do not consider the localised micromechanical behaviour. Here, single-grain micropillar compression tests in a Ni-base superalloy reveal that the micromechanical effect of shot peening could be insignificant due to the machining-induced pre-strained condition of the surface. Further, it is shown that shot-peening-induced strengthened layer can extend much less (∼50%) than the depth at which compressive stresses are still present. This work highlights the need for employing micromechanics as a complementary shot peening assessment technique for machined components.

DOI: https://doi.org/10.1016/j.cirp.2023.04.003