Which superalloys suit EDM best for intricate geometries?

Nickel-Based Superalloys

Nickel-based grades are the most suitable for EDM due to their high hardness, low thermal conductivity and complex microstructure that challenge traditional machining. Alloys such as Inconel 718LC, Inconel 713C and Hastelloy C-2000 are commonly used in hot sections of turbines and fuel systems where intricate channels and tight tolerances are required. EDM circumvents tool wear and work-hardening, enabling precise machining of deep recesses, sealing grooves and airflow contours.

Single-Crystal and Directionally Solidified Alloys

High-performance single-crystal superalloys—such as TMS-196, CMSX-series alloys and second-to-fifth generation systems—are ideal for EDM when cooling slots or film holes must be added without disrupting grain alignment. Because EDM is non-contact, it avoids residual stress, preserving the structural integrity of parts produced via single crystal casting or directional casting.

Cobalt-Based Superalloys

For wear-resistant components, cobalt-based alloys like Stellite 1 and Haynes 188 are excellent EDM candidates. Their hot hardness and abrasion resistance make complex machining difficult by traditional means. EDM enables accurate formation of sealing edges, spline features and precision wear interfaces without tool-induced vibration or deformation.

Powder Metallurgy Superalloys

Alloys manufactured through powder metallurgy—such as FGH96 and FGH97—have a fine grain structure and high strength that often require EDM for final shaping. Their homogeneous structure allows consistent spark erosion, resulting in burr-free features suitable for turbine discs and high-pressure rotors.