Vacuum-arc plasma source with extended cylindrical cathode

The experimental study of vacuum-arc plasma source with extended cylindrical cathode is carried out. The plasma source is intended for the protective coating deposition on articles having the form of closed containers. The plasma source cathode is fabricated as a cylinder with diameter 60 mm and length 750 mm. Aluminum is used as cathode material. Inside the cathode there is the cylindrical space where the magnetic system consisting of stabilizing coil and the controlling coil is arranged. The developed plasma source was used for aluminum coating deposition on the inner surface of cylindrical container of stainless steel with diameter 100 mm and the height 600 mm at the anode potential of arc discharge. To study the obtained coatings the stainless steel specimens were disposed on the end face and on the side surface of the container. Arc discharge current in the process of coating deposition was 100 A. The deposition rate was 12.5 mkm/h. Variation of coating thickness over the length, so that the variation of coating thickness on the side and face surfaces of the container makes up /spl plusmn/15%. It is shown that the proposed procedure of coating deposition is characterized by the high coefficient of the cathode material utilization factor, approaching 100%. The cathode spot control in the evaporator is effectively-realized in the range of arc current 100-200 A.