Electro-Discharge Grinding (EDG) PCD Spark Gap Calculator

4. Engineering Notes & Physics Specifications

Electro-Discharge Grinding (EDG / WEDG) Physics: PCD (Polycrystalline Diamond) consists of electrically non-conductive diamond crystals bonded within a conductive cobalt matrix catalyst (6%–12% Co). In EDG, electrical discharges preferentially melt and vaporize the conductive cobalt binder, releasing micro-diamond grains through hydrodynamic dielectric flushing.

Spark Gap Formulation: The effective overcut spark gap $S_g$ is governed by dielectric breakdown field strength ($E_{bd} \approx 10 - 20\text{ V/µm}$) and discharge energy: $$S_g = k_d \cdot V^{0.65} \cdot I_p^{0.32} \cdot T_{on}^{0.2}$$

CAM Prepress Compensation: Programmed toolpaths must apply an inward normal compensation offset equal to: $$\text{Offset} = R_{wheel} + S_g + \delta_{wear}$$ where wheel dress wear must be recalculated dynamically along multi-axis tangent arcs.