Method of rounding of tool cutting section and tool finished by the method

摘要

The cutting edge (2) of a tool (1) is immersed in an electrolyte, the tool (1) is connected to a positive pole of direct current supply and a negative pole of the supply is connected to an electrode immersed in the electrolyte. At the voltage higher than 100 V, a para-plasma envelope (4) is formed around the tool (1), wherein electro-plasma discharges run-over, the discharges cause evaporating of metal from the surface of the tool (1) and the rounding off (3) is formed on the cutting edge (2). At the tool (1) made of sintered carbide, the electro-plasma discharges remove binding material forming the matrix of the sintered carbide and subsequently, the carbide grains are washed away by the electrolyte. The electrolyte is e.g. water solution of non-toxic salts. The disclosed method is ecological and very productive, since the application of electro-plasma discharge during 10 to 150 seconds is sufficient. The rounding of the cutting edge (2) results in high productivity of machining.