US Patent 7641945 Electrical-discharge surface-treatment method

An electrode for an electrical-discharge surface-treatment method is molded with a metallic powder or a metallic compound powder having an average grain diameter of 6 micrometers to 10 micrometers. A coat on a surface of a workpiece is formed with a material constituting the electrode or a substance that is generated by a reaction of the material due to a pulse-like electrical discharge. The coat is built up with a material containing metal as a main constituent under conditions of a width of a current pulse for the pulse-like electrical discharge in a range of 50 microseconds to 500 microseconds and a peak of the current pulse equal to or less than 30 amperes.