Optimization of shot peening parameters for AA7B50-T7751 using response surface methodology

Abstract Shot peening (SP) parameters are optimized and their effects on fatigue life are investigated using a response surface methodology (RSM) for AA7B50-T7751. Three parameters (SP velocity, nozzle distance (hereafter called distance), and coverage) are optimized using the finite element method (FEM) to obtain the appropriate residual stress, average surface roughness (SR), grain-refinement, and micro-strain. The grain-refinement and induced micro-strain are calculated based on the full width at half maximum (FWHM). Moreover, the FEM results are consistent with the experiments. Optimized parameters are obtained by employing the Box-Behnken design (BBD) response surface methodology (RSM) based on the FEM results. Finally, fatigue experiments show improved fatigue lives for the treated specimens using the optimal scheme. It noted that the optimized parameters of SP velocity, distance, and coverage were 100 m/s, 14.2 cm, and 300%, respectively. Further, the fatigue lives of the AA7B50 samples peened using optimized parameters improve to 314.1%, 173.1%, and 23.9%, respectively, compared to three control groups.