Anode-Mechanical Metalworking

a method of machining metal by the combined electrochemical and elec-troerosional effects of an electrical current on the workpiece in an electrolytic medium. It was developed in the USSR by the engineer V. N. Gusev in 1943.

The workpiece (anode) and the electrode-tool (cathode) are generally connected to a DC low-voltage (up to 30 volt) circuit. An aqueous solution of sodium silicate Na₂Si0₃ (water glass) is Used as the electrolyte, sometimes with added salts of other acids. The materials employed for the electrode-tools are low carbon steels (08, 10, 20, and others). Under the action of the current, metal in the workpiece is dissolved and a passive film is formed on its surface. When the force of the tool on the workpiece is increased, the film is ruptured and an electrical discharge occurs. Its thermal effect causes local melting of the metal. The slurry thus formed is forced aside by the moving tool. Changing the electrical conditions and the force permits various surface roughnesses to be obtained on the workpiece (up to the 9th roughness class).

The metal-removing operation in anode-mechanical metalworking is accomplished by the electrical current in the interelectrode gap almost without any power loading on the components of an anode-mechanical machine tool, in contrast with a metal-cutting machine tool where these parts are heavily loaded. The rate of metal removal is practically independent of the mechanical properties of the processed metals and of the tool (hardness, toughness, and strength), and therefore it is expedient to use anode-mechanical metalworking for workpieces made from high-alloy steels, hard alloys, and the like. Anode-mechanical metalworking gives high technological and economic benefits when machining such materials: the productivity is increased, the amount of waste and the power consumption are decreased, and tool costs are drastically reduced. In finishing operations anode-mechanical metalworking can achieve a high-quality surface.