What is a Die Sinking Machine?

1. What is an Electrical Discharge Machining Machine?

An electrical discharge machining machine, also known as an electrical discharge punching machine, electro-erosion forming machine, or cavity electrical discharge machining machine, is a special type of machining equipment. It does not use traditional cutting tools; instead, it utilizes the instantaneous high temperature generated by a spark discharge to erode metal materials, thereby processing parts into the desired shape.

Simply put, it can be understood as a machine that "carves metal with sparks."

2. How a Die Sinking Machine Works?

The working principle of an electrical discharge machining machine is based on a key principle: in an insulating liquid, when two electrodes (tool electrode and workpiece electrode) are brought infinitely close but not in contact, a pulsed spark discharge is generated. The high temperature (up to 10,000-12,000°C) generated during the instantaneous discharge locally melts and vaporizes the metal material.

This process involves the following elements:
Two electrodes:
Tool electrode: Typically made of a highly conductive and corrosion-resistant material such as copper or graphite, its shape precisely complements the shape of the workpiece cavity to be machined (essentially a "stamp").
Workpiece electrode: The metal material being machined, such as mold steel or cemented carbide.
Insulating medium: Usually a specialized EDM oil. It serves to insulate, cool, and remove chips.

Machining process:
The tool electrode and workpiece electrode are immersed in the EDM oil.
Through a servo system, the tool electrode is slowly fed towards the workpiece electrode.
When the gap between them becomes small enough (typically a few micrometers to tens of micrometers), the insulation breaks down, generating a pulsed spark discharge.
The instantaneous high temperature melts and vaporizes a small point of metal on the workpiece surface.
After the discharge, the EDM oil cools and solidifies the molten metal particles and washes them away from the gap.
This process repeats thousands or even hundreds of thousands of times per second, with countless tiny discharge pits stacking up to ultimately "copy" the shape of the tool electrode onto the workpiece, creating complex cavities.

3. Features and Advantages of Die Sinking Machines

"Using Flexibility to Overcome Hardness": Capable of machining any high-strength, high-hardness conductive material, such as hardened steel, titanium alloys, and cemented carbide. The harder the material, the more pronounced the machining advantage.

No Macroscopic Cutting Force: The tool and workpiece do not contact each other during machining, eliminating traditional cutting forces. Therefore, it can machine thin-walled, flexible, and micro-sized parts with low rigidity without causing workpiece deformation.

Machining Complex Shapes: Capable of machining complex geometries and deep cavities and narrow slits that are difficult or impossible to achieve using traditional cutting methods, making it particularly suitable for machining mold cavities and holes.

High Precision and Good Surface Quality: Through precise control of electrical parameters, high dimensional accuracy and specific surface roughness can be achieved. The machined surface typically exhibits a uniform pitted appearance, which is beneficial for oil retention and lubrication.

4. Main Application Areas

The primary application area for EDM (Electrical Discharge Machining) machines is the mold manufacturing industry.
Injection Molds: Machining cavities for various plastic product molds.
Die Casting Molds: Machining cavities for die castings of aluminum alloys, magnesium alloys, and other metals.
Forging Dies: Machining cavities for forging dies.
Irregular Holes and Deep Cavities: Machining various irregular through holes, blind holes, and deep cavity structures.
Small Hole Machining: Using specialized small hole machining heads, efficient machining of deep small holes is possible.