Electrical Discharge Machining (EDM) is a technology for precision machining of metal, using a high electrical current passing through the machining tool (electrode or thin metal wire), to drill, cut or shape conductive metals. Electro-erosion enables precise machining of tools, fixtures and dies from hardened metals, and the manufacture of products from steel, exotic metals, such as: Titanium or kovar and other conductive materials, for example: Nitinol, alumina and ceramics integrated with conductive materials.
Hamavlet specializes in EDM wire cutting for precision manufacturing (≥ 0.01 mm) of metal parts at tight tolerances (±5µm) for different industries, including: aviation and aerospace, defense, medical devices and electronics.
The EDM working principle
A strong electrical current is passed through an electrode or thin conducting wire, which creates an electrical field in the narrow gap (0.005-0.05 mm) separating the workpiece and the electrode. Due to the potential difference between them, current discharge occurs (electrical spark), which erodes the metal. EDM wire cutting is characterized by high precision (≥ 0.01 mm), controlled and excellent surface quality (Ra 0.15-2.8 µm), without creating internal stresses in the raw material.
The cutting operation is carried out immersed in de-ionized water for:
- Electrical insulation between the workpiece and the electrode is necessary to maintain a potential difference between them
- Cooling the workpiece in order to prevent thermal effects at the cutting line
- Rinsing of waste - removal of a thin and insulating layer of soot created during the electro-erosion process
- Immersed cutting reduces the oscillation of the wire and therefore improves the cutting accuracy and surface quality.
EDM wire cutting advantages
EDM wire cutting of a complex fixture
- Precision cutting of intricate outlines, small diameter holes, and complex shapes from steel (t ≤ 400 mm)
- Cutting conical and irregular shapes
- High precision up to 10 microns (0.01 mm)
- High surface quality (Ra ≥ 0.15 µm), generally eliminates the need for additional surface treatments
- Full control over cutting parameters
- The resultant edge is burr free.
EDM manufacturing solutions
- Precision manufacturing of miniature parts: Hamavlet has extensive experience in micromachining of miniature components (Ø ≥ 0.5 mm) with a Ø 0.1 mm wire
- Small series and medium series manufacturing (stacking)
- Design and manufacture of dies and blanking tools
- Manufacturing of dedicated jigs and fixtures
- Gauges, calibration tools, tools for shape setting of medical implants.
EDM drilling / electrode drilling
Hamavlet is capable of drilling up to a depth of 300 mm, using Ø 0.3, 0.5, 1.0, 2.0 and 3.0 mm electrodes (generally brass or copper). Electrode drilling is used to prepare the initial holes for threading the cutting wire; for precision drilling of products mainly in the medical field; and for deep drilling and drilling hardened materials.