Combined Manufacturing Process of Copper Electrodes for Micro Texturing Applications (AMSME)

Abstract

Surface texturing has brought significant improvements in the functional properties of parts and components. Sinker electro discharge machining (SEDM) is one of the processes which generates great texturing results at different scale. An electrode is needed to reproduce the geometry to be textured. Some geometries are difficult or impossible to achieve on an electrode using conventional and even unconventional machining methods. This work sets out the advances made in the manufacturing of copper electrodes for electro erosion by additive manufacturing, and their subsequent application to the functional texturing of Al-Cu UNS A92024-T3 alloy. A combined procedure of digital light processing (DLP) additive manufacturing, sputtering and micro-electroforming (AMSME), has been used to produce electrodes. Also, a specific laboratory equipment has been developed to reproduce details on a microscopic scale. Shells with outgoing spherical geometries pattern have been manufactured. AMSME process has shown ability to copper electrodes manufacturing. A highly detailed surface on a micrometric scale have been achieved. Copper shells with minimum thickness close to 300 µm have been tested in sinker electro discharge machining (SEDM) and have been shown very good performance in surface finishing operations. The method has shown great potential for use in surfaces texturing.

Metrological Assessment of Microtextured EDM Electrodes Generated by Additive Manufacturing and Electroforming

“…One of the greatest technological challenges of modern engineering is to try to reduce the negative effects caused by the phenomenon of wear. This is a problem that is relevant to the life of metal parts [3]. That is why numerous investigations have been carried out with the aim of finding ways to improve friction and wear resistance of this type of surfaces, discovering that by developing specific surface topographies functional applications could be obtained [1,4,5].…”

“…1. It is then metallized on the part on its active surfaces by the sputtering process; and finally the part is introduced into a copper electrolytic bath by subjecting it to an electroforming process, resulting in a copper shell with its own integrity and variable thickness that becomes the textured tool used in the EDM process when assembled into an electrode holder specifically designed for this application [3]. To obtain the final tool different manufacturing processes are required, implying an accumulation of deviations from the CAD model, which requires an analysis.…”

Evaluation of the Performance of Atomic Diffusion Additive Manufacturing Electrodes in Electrical Discharge Machining

“…Electroforming uses a typical electroplating process but removes the metal shell from the pattern once the electroplating ends, thereby producing a high-quality surface reproducing the roughness and small features of the base model. The high level of reproducibility of an electroformed electrode is even suitable for micro-EDM, such as shown by Sánchez et al [ 15 ]. They produced an electroformed EDM copper electrode starting with a resin pattern made by Digital Light Processing AM (DLP, Vat Photopolymerization), resulting in an electrode more suitable for EDM finishing conditions, rather than roughing, due to the increase in the TWR.…”