The use of ultrasound to produce metallic powder in the plasma discharge electrolyte

In this work, a new process of plasma-electrolyte sputtering under the action of ultrasonic vibration is proposed, which makes it possible to obtain a finely dispersed metal powder with an average particle diameter of about 100 μm. The process involves irradiation with a high-power continuous laser on a consumable metal substrate vibrating at an ultrasonic frequency. The burning of a gas discharge around the vibrating electrode causes the surface to melt and small droplets are ejected. Preliminary results of spraying stainless steel 12X18H9T with a discharge power of 800 W and an ultrasonic vibration frequency of 20 kHz are presented. Vibration displacement does not significantly affect average particle size and size distribution according to capillary wave spray theory. The microstructure of the larger atomized particles exhibits a fine dendritic structure on the surface and shrinkage porosity at the center of the particles, indicating multiple surface nucleation for solidification. (paper)