electrical discharge

Electrons build up electrical discharge. They carry negative charge.

It won't "not go through". It will only discharge if there is an electrical circuit between the pads and the machine and there is sufficient charge in the capacitators.

The main difference between EDM (Electrical Discharge Machining) and ECM (Electrochemical Machining) machines is in their working principles:

EDM (Electrical Discharge Machining): EDM uses electrical discharges to remove material from a workpiece. It relies on sparks or discharges of electrical energy to erode the material, making it suitable for hard metals and complex shapes.

ECM (Electrochemical Machining): ECM employs a chemical process to remove material. It uses an electrolyte solution and an electrically conductive tool to dissolve or erode the workpiece material, making it effective for conducting materials like alloys and difficult-to-machine metals.

In summary, EDM uses electrical discharges, while ECM uses an electrochemical process to shape and machine materials.