Influence of shot peening on surface-layer characteristics of a monocrystalline nickel-based superalloy

Shot peening was conducted on [100]- and [111]-oriented monocrystalline nickel-based superalloy samples to study the effect of crystal orientation on the distributions of the residual stress and evolution of microstructures in the deformation layers on the sample surfaces as a function of the coverage up to 400%. The XRD results show that the orientation randomizations and the values of compressive residual stress in the [111]-oriented samples are relatively higher than those in the [001]oriented samples. Moreover, the residual-stress distribution in each sample is anisotropic, and the residual stress is maximum along the (110) direction. This phenomenon can be explained by the anisotropic properties of a single-crystal alloy and mechanism of the dislocation slip in the plastic deformation layers. Line profile analysis was also used to obtain microstructural information of the samples. (C) 2010 International Centre for Diffraction Data. [DOI: 10.1154/1.3506379]