How to cut aluminum to machine EDM aluminum parts by wire cutting

Aluminum can be cut by wire EDM because it is electrically conductive, but the process requires careful control of discharge conditions and debris removal. Common challenges include rapid power-feed contact wear, frequent molybdenum wire breakage and a shorter working-fluid service life. In this guide, DMNC, one of the professional CNC EDM machine suppliers, explains how to improve aluminum wire EDM stability through suitable pulse parameters, working-fluid management, electrode-wire selection and power-feed system maintenance.

1. Reasonable combination of pulse electrical parameters

When machining EDM aluminum parts by CNC wire cutting EDM, the wider pulse width is likely to produce larger alumina or particles with alumina on the surface. If the pulse interval is too small, it will also produce larger particles. The molybdenum wire easily adheres to these larger processed particles, which affects the conductivity and has a great negative impact on electrical discharging. Increasing the no-load voltage amplitude of the pulse power supply, reducing the pulse width and processing pulse gap can reduce the possibility of processing debris attached to the electrode wire(molybdenum wire).

2. Requirements for working fluid of moly wire EDM

In order to keep the moly wire EDM cutting fluid clean, make it work normally and effectively, and extend the service life of the working fluid, thick sponges can be used to prevent debris from flowing into the water tank, keep the waterway open, and reduce the adhesion of processing debris on the molybdenum wire. Clean or replace the sponge pad regularly. The amount of water sprayed from the upper and lower sides of the moly wire EDM fluid should be uniform and try to use a water tank with a good filtering effect to remove the erosion in time.

3.  Use a special brass wire

For an EDM wire cutting machine designed to use brass wire, a wire grade suitable for aluminum machining may help maintain more stable electrical discharge and reduce the influence of aluminum debris on the cutting process.

A brass wire diameter of 0.20 mm may be suitable for some machine configurations, but it should not be treated as a universal specification. The correct wire diameter and grade depend on:

• The wire transport and tension system

• The workpiece thickness

• The required cutting accuracy

• The pulse-power configuration

• The required cutting speed and surface finish

Brass-wire EDM and reusable molybdenum-wire EDM use different wire-feed, tension and power-contact systems. Brass wire should therefore not be installed directly on a molybdenum-wire machine unless the equipment manufacturer confirms that the machine is compatible with the selected wire. Before batch production, perform a trial cut and check the discharge stability, wire-breakage frequency, dimensional accuracy, surface finish and power-contact condition. The pulse parameters and wire tension should then be adjusted according to the test result.

4.  Install special aluminum cutting device

If the wire-cutting machine is used to process large quantities of EDM aluminum parts in the CNC EDM machine for sale, the processing problems will be more prominent, and the above-mentioned measures will not be able to fundamentally solve the problem. This needs to be considered from the perspective of machine transformation, and electrical conductivity is no longer used. The block power supply method, such as the wire barrel power supply method, can be suitable for production and processing. It is equipped with a special device for cutting EDM aluminum parts (carbon brush), which can supply electricity to the wire barrel and guide wheel, which can slightly increase the service life of the power feed contact.