Discharge surface treatment apparatus

A discharge surface treatment apparatus that:

• generates a pulsed discharge between poles comprising a discharge electrode and a workpiece, wherein the discharge electrode is obtained by compression-molding of any one of a metal powder, a powder of a metal compound, and a powder of ceramics or a mixture thereof;
• and
• forms a film made of an electrode material on a workpiece surface by thermal energy due to the discharge,
• the apparatus comprising:
• a capacitor that is connected to any one of the discharge electrode and the workpiece at one end;
• a switching element provided between another one of the discharge electrode and the workpiece and another end of the capacitor via a connection line;
• and
• a controller that keeps the switching element on until a lapse of a predetermined time after occurrence of a discharge from when a voltage is applied between the poles, keeps the switching element off for an arbitrary period of time, and thereafter, keeps the switching element on for a period until voltage application between the poles ends,
• wherein the capacitor is configured to generate a leading pulse current having a high peak value and a short pulse width;
• and
• the switching element is configured to block a flow of a reverse current occurred in the capacitor from flowing toward the poles when a subsequent current having a low current value and a long pulse width starts flowing between the poles.