Abstract
The study on the ejection process of the droplets from the edge of the molten surface during plasma rotating electrode process (PREP) of the titanium electrode was carried out under the condition in which an appropriate deviation between the plasma center and the rotating electrode center was applied.The experimental results suggest that the retaining force which principally consists of surface tension of the liquid phase and act to the each droplets, is affected by the local shape of the molten surface of the electrode where ejection of the droplet occures. At the lower plasma voltage, relatively sharp edge of the electrode was formed, and then the produced particle diameter was smaller than that obtained under the ordinary operation voltage. Such a result may be caused by formation of protuberances overlaped on the edge of the electrode. Further PREP experiments were carried out using the special electrodes whose surfaces were surrounded by the lines of protuberances. The results informed that existance of such protuberances introduce a posibility of obtaining the smaller particles and the decreased secondary particles.
