Last week Russian engineers have opened a plant of high-accuracy machines, working by means of electrochemical machining with vibrations, in the Russian city of Ufa.

The technique, known as electrochemical machining, has a long time been an outsider of precision manufacturing. However, researchers from Ufa have improved this technique and created machines, which “do things no one else can do”. In technical terms, these machines have almost best values of complex criterion precision-roughness-productivity among existing machines.

Such a machine can work with workpieces, made of almost any kind of commercial steels and alloys, including high-strength ones, metal ceramic, nanostructured alloys; create super-smooth surfaces (as rough as 0.02 microns) on very large surfaces for precision equipment, and cutting edges with a radius, less than 1 micron.

Extremely high accuracy and computer programming allow new machines can create vary complicated parts with surface of such a high quality, that cannot be achieved with any other technique; moreover, these machines can apply coatings as thin as 10 nanometers and having different composition – for wear resistance increase, corrosion protection or strength improvement.

 

 

The technique is based upon a traditional technology of electrochemical machining of metal: a workpiece is a positively charged electrode, and a processing tool – a negatively charged electrode. When electric current is supplied, electrolysis “dissolves” excessive material, which precipitates as sludge. Electrolyte flow removes sludge from interelectrode space; after that sludge is filtrated, and electrolyte can be reused. In simple words, electrochemical machining requires only energy and water, however, for a long time this technique was considered to have low precision level.

An innovation of Russian engineers has destroyed abovementioned point of view. The essence of the innovation is following – electrodes, oscillating in an electrolyte, receive microsecond pulses of high-density electric current. This vibration allows highly accurate localization and control electrochemical reactions in extremely small space. Special scheme of pulse supply creates special physical and chemical conditions on electrode surface and in electrolyte – these conditions provide increase in accuracy and productivity of this technique.

An innovative machine consists of three units: an switched mode power supply, a mechanical centre, and a hydraulic system with electrolyte and computer control unit. Pulse power determines an area of work surface – maximum pulse power of 6000 Ampere allows processing steel surface with area of 70 square centimeters and working with workpieces, weighing up to 100 kilograms. A hydraulic system works on closed cycle and is connected with a automatic electrolyte purification unit.

A computer unit allows automatic control of processing regimes – user-friendly interface and a number of embedded technological programmes allows anyone without special training to control a machine. These machines can self-learn and work without operators – at night or during holidays.

These machines have wide technological applications – machine- and airplane-building industry, microsurgery, implantology, electronics and jewelry industry.