Technological and economical comparison of roughing strategies via milling, sinking-EDM, wire-EDM and ECM for titanium- and nickel-based blisks

Due to their particular mechanical and thermal properties titanium- and nickel-based alloys such as Ti–6Al–4V or Inconel 718 are in common use as blisk materials. Besides conventional milling in this paper two alternative technologies for roughing operations in blisk manufacture – electro discharge machining (EDM) and electrochemical machining (ECM) – are presented. Therefore material removal rates in sinking-EDM (SEDM) and ECM as well as cutting rates in wire-EDM (WEDM) are determined for the above mentioned materials and class of geometries. With these results, an extensive cost-analysis is made where different production technologies are compared for analogical blisk geometries. It is demonstrated that for distinct geometries, materials and batch sizes unconventional manufacturing technologies are economic alternatives to existing milling strategies.