Developments in Wire-EDM for the Manufacturing of Fir Tree Slots in Turbine Discs Made of Inconel 718

Abstract:

This paper deals with developments of Wire-EDM technologies for fir tree slot production. The aim of these developments is to substitute certain conventional processes within turbine manufacturing that have been identified as non-optimal like the critical broaching process. Thereby the negative characteristics like inflexible manufacturing processes, high machine tool investment costs and huge energy consumption can be abolished. The objective targets of the conducted research are to meet all safety requirements of the critical components and get an economic manufacturing process. In the first step a special brass wire technology for cutting Ni-based super alloys was developed. Main focus was to meet the requirements of fir tree production concerning aspects of surface integrity and geometry. To measure these aspects on the one hand non-destructive analyses have been performed to guarantee surface roughness and accuracy. On the other hand destructive analyses in terms of cross section polishing for showing thermal influenced rim zones have been prepared. A capable Wire-EDM process is presented.

• Periodical: Key Engineering Materials (Volumes 504-506)
• Pages: 1177-1182
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.504-506.1177
• Online since: February 2012
• Authors: Fritz Klocke, David Welling, Jens Dieckmann, Drazen Veselovac, Roberto Perez
• Keywords: Destructive Analysis, Fir Tree Slots, Inconel 718, Surface Integrity, Wire-EDM

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