On the causes of gripping of electrodes from Ag, Cu and Ni under the influence of low-voltage pulsed discharge in the process of coatings deposition

L.Kryachko,
  

I. M. Frantsevich Institute for Problems of Materials Science of the NAS of Ukraine, Omeliana Pritsaka str.,3, Kyiv, 03142, Ukraine
Powder Metallurgy - Kiev: Frantsevich Institute for Problems of Materials Science NASU, 2009, #09/10
http://www.materials.kiev.ua/article/1508

Abstract

The conditions for the appearance of gripping of electrodes from Ag, Cu and Ni under the influence of low voltage pulsed discharge in the process of coatings deposition on a copper plate have been studied. It has been established that the increased tendency of nickel toward the gripping is caused by the higt surface tension of its melt, which prevents the evacuation of liquid metal from the anode surface, and also by the comparatively low thermal conductivity of nickel, which limits heat withdrawal from the supporting points of the discharge channel into the electrode. This determines smooothing of the electrode surface relief, an increase in the contact area and a rise in the temperature of contact interaction of the electrode pair, which increases the probability of gripping.