Reduplication of precise internal geometries by pulsed electrochemical machining

In the field of spare parts production with small quantities and low stockholding one main method is reduplication of precise internal geometries from a defect part to a spare part. One conventional manufacturing technology for this reduplication is broaching. Since broaching requires extensive and expensive tools especially for small quantities a more resource efficient technology is aspired. Electrochemical machining (ECM) is a potential technology which meets these requirements. ECM transfers a cathode geometry to a workpiece based on anodic dissolution [1]. For this purpose, a specific design for the cathode as well as for the process is required [2]. In the context of process design multiphysics simulation allows a time- and cost-efficient determination of proper process parameters and enables conclusions for the optimization of the cathode geometry [3]. The paper shows an experimental study on the reduplication of precise internal geometries using pulsed electrochemical machining (PECM) applying a two-step approach. Therefore in a first step an initializing workpiece was used to generate a cathode with PECM. This initializing workpiece consists of an internal bore with a diameter of 32 mm. In the second step the reduplication of this internal bore into a workpiece by PECM applying the generated cathode was performed. The workpiece was made of a hardened powder metallurgy steel SAM 10. In the experiments the voltage was varied in a range from 10 V to 17 V and the feed rate was varied from 0,5 mm/s to 1,1 mm/s. By help of the experimental study the influence of both PECM processes on the reduplication result can be determined.