How does EDM’s material removal rate compare to other post-processing methods?

Comparison of Removal Mechanisms

EDM’s material removal rate (MRR) is based on electrical discharge erosion rather than cutting or abrasion, making it slower than conventional machining or grinding. However, it excels in processing superalloys that are difficult to cut—such as CMSX-11 and Hastelloy X—where tool wear and heat damage limit the efficiency of milling or grinding.

Compared with abrasive finishing or CNC machining, EDM maintains high precision on hardened or complex shapes but typically generates a lower MRR due to controlled pulsed erosion.

Relative Performance vs. Conventional Processes

Traditional CNC machining may remove material at a rate of tens of cubic centimeters per minute, while EDM removal rates are often lower but far more consistent on difficult materials. Grinding can achieve faster MRR for surface finishing but struggles with intricate geometries and internal cavities. EDM, especially sinker EDM, can remove material uniformly even in deep cavities and thin-wall regions—without inducing stress or tool deflection.

To balance speed and precision, EDM is frequently paired with superalloy CNC machining, where EDM performs rough shaping and CNC finishing refines tolerances and surface quality.

Application-Based Selection

In aerospace and power generation applications, MRR is not the only performance criterion—structural stability, cooling channel precision and microstructural integrity are often more critical. EDM is therefore preferred when traditional methods risk mechanical damage or cannot reach complex internal geometries.

Ultimately, EDM offers a lower material removal rate—but superior control and reliability—making it indispensable for critical post-processing of advanced superalloy components.