Hydraulic turbine components that define the water flow, generally have a complex geometry. In the design of these components a major role is played by model tests. The complex geometry of runner�s blades and wicked gates determines high manufacturing times and high fabrication cost if they are made by classical manufacturing technologies (casting, machining on numerically controlled machines). The use of high resolution 3D printing reduces the production time, simplifies the manufacturing technology and generate high dimensional accuracy. The paper presents the design and the manufacturing process of the components from a new solution of axial hydroturbine, equipped with a permanent magnet generator and an immersed runner. The manufacturing of the main parts of the turbine (runner and wicked gates) it was made by Rapid Prototyping.

This paper presents the cavitation erosion research through the stationary specimen method of the X20Cr13 martensitic stainless steel. Actual research involves a number of 4 different tests for this material and the comparison between these experimental tests is highlighted by the images and graphs forwarded in the paper. All research was done using vibratory apparatus composed from electro-acoustic piezo-converter, acoustic transformer, a titanium sonotrode and the ultrasonic generator DG-2000. The mass loss of the martensitic stainless steel samples was measure with special digital balance.