Fundamental study of the electrical and acoustic characterization of different types of single discharges in wire electrical discharge machining (WEDM)

• Applicant: Professor Dr.-Ing. Thomas Bergs
• Subject Area: Metal-Cutting and Abrasive Manufacturing Engineering
• Term: since 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 495708473

In wire EDM, there is a lack of basic understanding of the individual energetic contributions made by the interaction of the different types of discharge that occur. In addition, the influence of these discharge types on material removal and rim zone formation is largely unexplained. The clarification of these correlations would create a necessary condition for the energetic documentation of the process in order to obtain the needed knowledge for certification. The research hypothesis is the following:With the means of single discharges in wire EDM, different types of discharges can be specifically generated, energetically characterized and their specific removal processes can be described.The implementation of the single discharge functionality for industrial wire EDM machines and the resulting ability to trace the continuous process back to its individual contributions is the core of the research approach. In this way, different discharge types can be investigated separately and their effects on the local material modification can be precisely characterized. In contrast to the continuous process, which does not allow this specific correlation and only enables a general analysis of converted energy and removal rate, individual discharges can be used to build up a basic understanding of the process, which can then be transferred back to the continuous process. For this purpose, a suitable mechanism for generating single discharges on a commercial wire EDM machine must be implemented. On this basis, the specifics of and the influencing variables on standard discharges can first be investigated. By varying the discharge energy, the material and the wire material, the previously uncertain wire erosion-specific phenomena can be characterized in principle. Subsequently, further technical solutions are developed to generate not only standard discharges but also abnormal discharges and short circuits. In this way, the conditions prevailing in the continuous process are reproduced separately and described in terms of the amount of energy introduced into the material and the resulting individual material removal. For this purpose, a measurement and evaluation methodology of combined electrical and acoustic process signals is established, and a relative thermal analysis of the energy dissipation into the material is carried out.

• DFG Programme: Research Grants