FINISH PROCESSING METHOD FOR SINTERED METAL VIA ELECTROCHEMICAL MACHINING

摘要

PURPOSE:To ionize even a parent metal in addition to a bonding material for sintered metal and obtain a glossy surface by supplying pulse current of specific current density between a workpiece and a processing electrode in processing the workpiece comprising sintered metal. CONSTITUTION:An electrolytic product generated by filling a machining fluid free from an electrolytic product between a processed surface 2a and an electrode surface 4a opposing a gap 18 and supplying pulse current, is eliminated and the electrode surface 4a is again made in contact with the processed surface 2a. Processing depth per processing is measured and a value obtainable therefrom is accumulated. The aforementioned process is repeated with a control device 12. The process terminates when the accumulated value reaches within the predetermined difference, compared with a set value calculated by a processing condition control part 10 on the basis of data from an input device 13. When pulse current of low current density is fed in finishing sintered metal, only a metal composition liable to being eluted depending upon ionization tendency is eluted. By supplying the pulse current of current density equal to or above 110A/cm2, surface roughness is improved regardless of the ionization tendency of the metal composition.