ECM & Non-Traditional Machining

Electrochemical Machining (ECM) & PECM Cathode Gap Calculator

Precision tool for non-traditional machining engineers and turbine tooling designers. Calculate frontal equilibrium gap (y_eq), anodic dissolution current density, side overcut tapers, and cathode shape corrections for ECM and PECM.

1. Input Parameters

Typical DC/pulsed potential: 8 - 22 V.
Anodic + cathodic polarization drop: 1.5 - 2.8 V.
Aqueous NaNO3 or NaCl (10-25 wt%): 10 - 20 S/m at 30°C-40°C.
Linear tool plunge speed: 0.5 - 3.0 mm/min.
PECM pulse duty: 10% - 30% (pulse on-time / period).

2. Calculation Results

Frontal Equilibrium Gap (y_eq)
0.18 mm
Current Density (J_front)
81.9 A/cm²
Side Overcut (Δy_side @ 10mm)
0.34 mm
Volumetric MRR per 100A
2.12 cm³/min

3. Dynamic Schematic & Tooling Guide

ECM Cathode Design Rules:
  • Cathode Undersize: The cathode tool profile must be retracted by exactly y_eq along the plunge face and by the non-linear side overcut y_side(x) along the relief lands.
  • PECM High-Precision Micro-Gaps: Pulsed PECM with synchronized tool oscillation enables ultra-tight frontal gaps of 10-30 μm without boiling the electrolyte.
  • Electrolyte Flush Ports: Maintain minimum flow velocity of 20-30 m/s across the inter-electrode gap to evacuate dissolved metal hydroxides and hydrogen bubbles.
📖 Read Full Prepress Guide: ECM Cathode Vector Prepress Guide →