What kind of EDM processing? In what cases can CNC processing not be used and EDM processing must be used?

    In modern manufacturing, the ability of precision machining technology to form complex parts directly affects the performance and quality of products. As a non-contact special machining technology, electrical discharge machining (EDM) has become an "invisible engraver" for high-hardness materials and complex geometric parts by virtue of its unique machining principle. This article will analyze the technical principles, core advantages and applicable scenarios of EDM, and compare it with traditional CNC machining to help you understand its key role in industry.

    The EDM machine tool generates instantaneous high temperature (up to 8000-12000℃) through high-frequency pulse discharge between the electrode and the workpiece, causing the metal material on the surface of the workpiece to partially melt and vaporize, and gradually eroding the material. The entire process does not require physical contact, so it is not limited by the hardness of the material and can achieve micron-level precision. EDM machine tools can process high-hardness conductive materials such as hardened steel, cemented carbide, and titanium alloy. And through electrode shape replication or wire cutting path control, complex structures such as deep grooves, micropores, and special-shaped cavities can be processed, and fine structures that CNC processing cannot perform can be processed. The EMD processing process has no mechanical cutting force, avoids deformation of the workpiece, and is especially suitable for thin-walled and fine parts. At the same time, EDM processing can achieve mirror effects or specific roughness requirements by adjusting the discharge parameters.

1. Mold manufacturing field

Injection molds and die-casting molds: Processing complex cavities such as deep cavities, narrow slits, and sharp corners to solve the interference problem of traditional CNC tools.

Precision stamping molds: Directly process cutting edges and gaps with micron-level precision on hardened mold steel.

2. Aerospace and medical equipment

Engine blade film cooling holes, fuel nozzle micropores (aperture can be as small as 0.1mm).

Titanium alloy precision parts of surgical instruments (such as porous structures of orthopedic implants).

3. Superhard material processing

Special-shaped cutting edges of cemented carbide tools, precision slotting of polycrystalline diamond (PCD) tools.

Processing method

EDM Machine Tools

CNC Machine Tools

Processing principle

Spark erosion (non-contact)

Mechanical cutting (contact type)

Applicable Materials

Conductive material (hardness not limited)

Conductive material (hardness not limited)

Processing efficiency

Slow (low material removal rate)

Fast (suitable for large quantities)

Processing accuracy

Within ±1μm (precision grade)

±5-10μm (normal)

Surface quality

No knife marks, but remelting layer may occur

Direct cutting surface formation

Typical costs

Electrode design and loss costs are high

Tool cost is low, but depends on material machinability