Electrosion unveils compact ECM machine

Electrosion has launched a compact ECM machine that brings very small electrode gaps, speed and fuzzy logic to electrochemical machining.

The ECM 500 uses Electrosion's Impulse technology, which simultaneously pulses the power and the electrode so that extremely fine detail can be accurately reproduced in very hard materials such as tungsten carbide, making the machine ideal for use in the manufacture of cutting inserts, punches and dies.

ECM differs from EDM in that the workpiece dissolves into the sodium nitrite electrolyte.

The advantages of ECM are that metal removal rates are up to 100 times faster than EDM, and electrode wear is virtually zero, making it unnecessary to manufacture multiple electrodes, and there is no stress or heat introduced into the workpiece.

The disadvantage up until now has been that, due to the significant electrolyte flush rates required by the process, large gaps had to be used, making it virtually impossible to manufacture fine detail.

With its Impulse pulsed flushing technology, the ECM 500 enables engineers to achieve electrode gaps down to 10 micrometres, which makes it possible to produce precise and intricate part geometry, while retaining the advantages of rapid metal removal.

Cavities and parts produced with the machine will require little or no polishing, with surface finishes of 0.1 micrometres Ra easily achievable.

Steve Duffield, managing director of Electrosion, said: 'Oscillating the electrode and the current has made it possible for us to produce a machine which can erode any conductive material, irrespective of its hardness, achieve metal removal rates of 1000mm3 per minute and, with care, surface finishes of 0.03 micrometres Ra with no electrode wear.' Working in a joint venture with the Moscow State Aviation University, Electrosion has created a control system for the ECM 500 that uses fuzzy logic principles.

The technology eliminates the skills required by the operator to achieve repeatability, making ECM a process which will fit into any manufacturing environment.

The ECM 500 can now machine tungsten carbide and titanium.

The machine can erode tungsten carbide 10 times faster than a laser, and produce a surface finish of 0.2 Ra or better.

For manufacturers, the technology will enable parts such as titanium femoral implants and tungsten carbide punches, dies and cutting inserts to be machined economically.