The Influence of the surface hardness on the atomization performance of ultrasonic atomizer

Abstract In the actual production of ultrasonic atomization, to cater to the consumers’ preference for the appearance of the products, the surface of the ultrasonic atomizer needs to be treated with different machining processes, which tend to affect the surface hardness of the atomizer, and affect the atomization performance of the atomizer. Therefore, the beauty of the appearance and the reduction of atomization performance has become a contradiction in the current industrial production of atomizers. In this study, it is theoretically proved that the hardness is inversely proportional to the atomization rate. Two machining processes are selected among the five common processing techniques for the experiment: (1) mirror polishing treatment of the atomizer, and (2) mirror polishing-sandblasting-plasma spraying treatment of the atomizer. To evaluate various aspects of the atomizer’s performance, several experiments were conducted, focusing on the hardness of the atomizer’s surface, its vibration displacement and the atomization performance. The results indicate that there is an inverse relationship between the atomization rate and the surface hardness, while the atomization rate is directly proportional to the peak vibration displacement. These findings align with the theoretical predictions. Following the process (2) treatment, the atomizer’s surface developed a frosted texture. As a result, its hardness increased by approximately 13.6%, the peak vibration displacement decreased by around 23.46%, and the atomization rate dropped by about 30.59% compared to the untreated atomizer. After the treatment of process (1), the surface of the atomizer had a mirror texture, where the hardness decreased by around 26.8%, the peak vibration displacement increased by approximately 64.2%, and the atomization rate increased by approximately 110.81%, compared with the untreated atomizer. The hardness influences the atomization rate by affecting the vibration displacement of the ultrasonic atomizer.