Investigation of the correlation between nozzle structure and particle motion during shot peening using the PIV method

Shot peening is a mechanical surface treatment process that enhances the fatigue performance of metallic components. Numerous studies have demonstrated the significant influence of peening particles’ motion on the quality of treatment. However, previous research has not established a connection between particle motion characteristics and nozzle structure. The nozzle structure directly affects both airflow characteristics and shot movement, making it crucial to examine how it influences particle motion to optimize both nozzle design and process parameters. To accurately determine the motion characteristics of particles, this study constructs a high-speed camera system for capturing their movements and uses the Particle Image Velocimetry (PIV) method for analysis. This study thoroughly investigates how factors such as jet pressure, nozzle diameter, and length affect shot motion behavior. The results indicate positive correlations between particle velocity with jet pressure and nozzle length while showing a negative correlation with nozzle diameter. Modifying structural parameters can effectively regulate both the velocity and dispersion angles of particles during peening operations under specified jet pressure conditions. Furthermore, based on experimental findings, a new prediction model for particle velocity considering structural parameters associated with nozzles was proposed.