Predicting the evolution of electrochemical trepanning for inner blisks with a chamfer structure at blade tip

Electrochemical trepanning (ECTr) is an effective electrochemical machining (ECM) technique that can be used to manufacture the integral components of aero-engine compressors. This study focused on the dynamic evolution of ECTr for production of inner blisks (bladed disks) with a special chamfer structure at blade tip. Due to the existence of chamfer, the ECTr process of inner blades is in a non-equilibrium state during the early stages, and the physical field changes in the machining gap are complex, making it difficult to predict the forming process. In this paper, a dynamic evolution model (DEM) of inner blade ECTr with a special chamfer at blade tip structure is proposed, and an ECTr multi-physical fields simulation study was carried out. The evolution of the chamfer at blade tip was analyzed and data related to chamfer were predicted based on the dependence of anode boundary properties with machining time and feed rate. In addition, the distributions of current density, electrolyte flow rate, bubble volume fraction, temperature rise, and electrolyte conductivity in the machining area at different times were obtained by combining them with the multi-physical fields simulation results. Subsequently, a series of ECTr experiments were conducted, in which, as the feed rate increased, the surface quality and machining accuracy of the inner blades were improved. Compared with the simulation results, the error in machining accuracy of the chamfer profile is controlled within ± 2%, and the machining accuracy of the blade full profile was controlled within ± 0.2 mm, indicating that the model proposed in this study was effective in predicting the evolution of inner blades ECTr with chamfer structures at blade tip.