Abstract
The widespread use of additive manufacturing and modern powder-based technologies (thermal spraying, hardfacing, sintering) encourages the search for alternative routes enhancing the development of metal and metal alloy powders. The state-of-the-art powder production processes, like gas, water or plasma atomization, are dedicated to mass production, which limits the availability of new powder compositions with desired characteristics. In this study, stainless steel powders were investigated. The powders were atomized by an in-house developed ultrasonic (UT) atomization set-up, called ULTRAMIZER. In this system, the atomization of melt is possible by using a high-power ultrasonic field. The atomized powders were characterized in terms of morphology and particle size distribution (PSD). The powder features were then correlated with operating parameters of: (i) UT atomization system, mainly frequency and root mean square power (RMS), and (ii) the orientation of the atomization plate against the melting system, by means of distance and tilting angle. The study shows that the ultrasonic atomization allows producing nearly spherical, defect-free powder particles, with a very narrow and controllable size distribution. These are important advantages over other metal powder production methods, especially when it comes to the development of new types of powder.
