COATING APPLICATION UNIT Russian patent published in 1994 - IPC

FIELD: vacuum-plasma treatment of tools. SUBSTANCE: coating application unit has vacuum chamber serving as anode and accommodating internally at least two cathodes of arc evaporators. Positioned inside vacuum chamber between cathodes is item holder with insulated current carrying conductor. Besides, unit is provided with power sources in number of arc evaporators. Placed between cathode and holder is optically opaque rotary screen. Required mode of operation is selected with the aid of double-pole key and reversing key. One of poles of reversing key is connected with switch of double pole key and the other with vacuum chamber. Power source is connected to switches of reversing key. One of poles of double-pole key is connected with holder. During exposition of heated item to be treated in nitric plasma (nitriding) positive pole of power source is connected with cathode with the aid of double-pole and reversing keys. In this case screen is closed. In the course of application of hardening coating cathode is connected with negative pole by means of reversing key and negative potential is fed from power source to holder. In this case screen is open. EFFECT: improved wear resistance of items. 1 dwg