This is predominantly a qualitative study on the manufacturing of micronozzles with an additive manufacturing (AM) technique, namely the laser-powered powder bed fusion (PBF-LB).  Manufacturing of micronozzles with standard microelectromechanical system technology often results in 2.5-D or close to 3-D structures and does not yield a fully rotationally symmetric nozzle. For this reason, AM can be a better solution. However, the structures obtained with PBF-LB exhibit very rough surfaces which will impair the performance of the micronozzle. To improve the surface finish electropolishing was performed on the interior walls.  Given the shape and the scale of the components, uniformity of the polishing is a challenge, calling for an inventive electrode configuration and electrolyte feed solution. The approach was to integrate an electrode on the inside of the converging part of the nozzle, to serve as a cathode for the electropolishing, already in the process, and to make the nozzle itself the vital part of the fluidic system.  With this, titanium micronozzles were manufactured with throat diameters varying between 300 and 800 μm. With the resolution of the used AM technique, it was possible to integrate the internal electrode in the micronozzles with a designed throat diameter down to 600 μm. Below this, the anode, and cathode, sometimes made contact short-circuiting the cell. Profilometry showed a decrease of the average surface roughness (𝑅𝑅𝑎𝑎) with 15-60 % for the electropolished micronozzles. The Schlieren imaging showed an exhaust that followed the throat’s axial direction and also demonstrated pressure disks and, hence, a supersonic jet exhaust. This study has shown that AM is a viable choice for manufacturing of rotationally symmetric micronozzles, and that electropolishing could be used to decrease the surface roughness on their inside uniformly with the integration of a cathode.

The theoretical part of the thesis contains a brief overview of some experimental methods that are used in machining technologies. The experimental part at first elaborates on the analysis of two titanium alloys. The actual experiment, which consists of milling of the two aforementioned materials with the use of several tools and holders, is then described. It was conducted in collaboration with the company Frentech Aerospace s.r.o. When milling, forces were measured with piezoelectric dynamometer. Further, the analysis of acquired data that is followed with discussion about its main findings, is provided. The conclusion of the thesis deals with the found facts corresponding with the information obtained by analysis of materials. The main results arise out of the comparison of used combinations of tools and holders for milling of material Ti-Al6-V4, observation of impact of particular factors on measured force, or out of different values of measured forces when milling two given materials.