Electrode for electrical discharge surface treatment and method for producing same

A method for producing an electrode for forming a coating film on a surface of a workpiece, made of a material of an electrode material or a reactive substance of the material of the electrode, by electrical discharge surface treatment that generates discharges between the electrode and the workpiece, the method comprising:

• producing granulated powder by granulating a powder containing any of a Co-base alloy, a Ni-base alloy, and an Fe-based alloy as a raw material thereof;
• forming a green compact by compression molding of the granulated powder;
• forming a sintered body as the electrode by sintering the green compact, wherein
• the powder includes a fine powder having a median diameter of 3.0 μm or less and formed in scaly shapes,
• a pressure in the compression molding and a sintering temperature in the sintering are set to values at which a specific surface area of the sintered body has a value in a range from 0.8 m2/g to 10 m2/g and an electrical resistivity of the sintered body has a value in a range from 3 mΩ·cm to 30 mΩ·cm,
• the pressure in the compression molding is set to a value in a range from 50 MPa to 300 MPa, and
• the sintering temperature is set to a value in a range from 450° C. to 950° C.

An electrode for forming a coating film on a surface of a workpiece, made of a material of an electrode material or a reactive substance of the material of the electrode, by electrical discharge surface treatment that generates discharges between the electrode and the workpiece, the electrode comprising

• a sintered body as the electrode, made of a powder containing any of Co, Ni, and Fe as a single raw material thereof, wherein
• the sintered body includes a fine powder of the raw material formed in scaly shapes,
• a median diameter of the fine powder is 4 μm or less,
• a specific surface area of the sintered body has a value in a range from 0.8 m2/g to 1.2 m2/g, and
• an electrical resistivity of the sintered body has a value in a range from 3 mΩ·cm to 30 mΩ·cm.

A method for producing an electrode for forming a coating film on a surface of a workpiece, made of a material of an electrode material or a reactive substance of the material of the electrode, by electrical discharge surface treatment that generates discharges between the electrode and the workpiece, the method comprising:

• producing granulated powder by granulating a powder containing any of Co, Ni, and Fe as a single raw material thereof;
• forming a green compact by compression molding of the granulated powder;
• forming a sintered body as the electrode by sintering the green compact, wherein
• the powder includes a fine powder having a median diameter of 3.0 μm or less and formed in scaly shapes,
• a pressure in the compression molding and a sintering temperature in the sintering are set to values at which a specific surface area of the sintered body has a value in a range from 0.8 m2/g to 1.2 m2/g and an electrical resistivity of the sintered body has a value in a range from 3 mΩ·cm to 30 mΩ·cm,
• the pressure in the compression molding is set to a value in a range from 10 MPa to 30 MPa, and
• the sintering temperature is set to a value in a range from 450° C. to 950° C.