Investigation of Surface Treatment Technology Using Water Droplet Impingement

Abstract

The handling pressure of water jet has been recently increased in order to achieve a high efficiency of surface treatment of materials. An experimental study of middle pressure water jet peening was conducted to investigate the evaluation method for the surface treatment of material and impact conditions of droplets such as size, frequency and velocity. It was found that the damage depth rate was useful for evaluating the degree of damage to material, which was directly identified with the intensity of the surface treatment. The craters caused by the impact of droplets were recognized using aluminum foils mounted on the specimen, and the distributions of droplet diameter and frequency were obtained. The droplet velocity was calculated by the equation of droplet motion. The damage depth rate well related to the kinetic energy of droplets impacted to the target. The impact conditions of water droplets which were needed for new developments of highly efficient water jet nozzles were thereafter discussed.