Enhancing the Functional Characteristics of Cast Parts Produced by Additive Technologies through Surface Roughness Reduction Using Electrochemical Polishing

Abstract

The objective of this work is to reduce the surface roughness parameters (Ra, Rz) of nickel-based alloy turbine blades, manufactured by investment casting using a 3D-printed polystyrene pattern, to the levels required by technical documentation through electrochemical polishing (ECP). Initial and final roughness values were measured with a contact profilometer “Model 130 (Version 7)” in accordance with GOST 2789-73; notations follow GOST ISO 1302. It is demonstrated that ECP ensures a significant reduction of Ra and Rz on both the concave and convex blade surfaces, including cases with preliminary blasting. The treatment was performed locally, without full immersion: only the required surface areas were polished. The influence of the obtained roughness values on the aerohydrodynamic efficiency of the flow section is discussed, as well as the applicability of ECP as a preparatory stage for functional coatings.