METHOD FOR ELECTRIC-SPARK ALLOYING AND APPARATUS FOR PERFORMING THE SAME Russian patent published in 1999 - IPC

FIELD: face hardening and restoring machine parts, cutting tools, dies and so on. SUBSTANCE: method comprises steps of imparting to electrode oscillation with frequency 100-1000 Hz; detecting time moment of electrode contact with alloyed surface of blank-electrode at each oscillation period; applying additional electric current pulse (5-20)A to electrodes at time moment of detecting said contact and providing pulse duration corresponding to time period of electrode contact; applying electric current pulse to electrodes with time delay relative to contact moment; selecting time delay according to relation t_d= (0,4-0,9)=(0.4-0.9)t_c where t_d- time delay period, t_c-time period of electrode contact. Pickup for detecting contact between electrode and blank-electrode in apparatus for performing the method is connected with input of delay unit. First switch is connected with positive pole of direct-current source. Negative pole is connected with blank-electrode. Apparatus is provided with second direct-current source and pulse shaper having two connected in series induction coils and diode. Contact detecting pickup is connected with control input of second switch. Leading end of first induction coil serves as input of pulse shaper and it is connected with output of first switch and through second switch - with positive pole of second direct-current source. Output of time delay unit is connected with control input of first switch. Negative pole of second direct-current source and positive pole of diode are connected with blank-electrode. Final end of first induction coil and leading end of second induction coil serves as output of pulse shaper and they are connected with electrode. EFFECT: high quality of alloying, enhanced efficiency. 2 cl, 1 dwg