Numerical modelling and experimental approach for shot velocity evaluation during ultrasonic shot peening

Abstract

Ultrasonic shot peening is a process of surface treatment which enhances mechanical properties of materials by inducing compressive residual stresses in the surface layer. As one of the most important process parameters during ultrasonic shot peening, shot velocity significantly affects the extent of plastic deformation and the microstructure formed on the surface of treated material. Due to the high frequency of change in the magnitude and direction, shot velocity is complicated to calculate exactly. For that reason, it is usually simplified as a constant. In this study, the velocity of a single shot during ultrasonic shot peening is measured experimentally using a high speed camera, and computed with theoretical model. The proposed mathematical model simulates the impact behaviour of a single shot during ultrasonic shot peening by introducing the restitution coefficient. Research results indicate that the shot velocity calculated by the proposed model agrees well with the experimental results. In addition, the effect of the ultrasonic shot peening parameters on the shot velocity was investigated. Research results will provide reliable technique instructions for the parametrical design of the ultrasonic shot peening technique.