Abstract: A plasma forming electrode used in pairs disposed in mutually facing spaced parallel relation in a reduced pressure treating chamber, and between which a radio frequency current power is applied to produce a plasma, is formed from preferably highly pure aluminum or an aluminum alloy, and has a chromic acid anodic surface film layer thereon. It has greatly improved durability when used for plasma treatment in the presence of fluorine containing gas.

Abstract: A method for continuously electrolytically processing a metal web in which the consumption rate of graphite electrodes is remarkably reduced. Auxiliary anodes made of a nonreactive material are provided separately from the graphite electrodes. One half of a symmetrical waveform is applied directly between the graphite electrodes, while for the other half of the waveform, a portion of the current is distributed through the auxiliary anodes. In this manner, the magnitude of the current contributing to a cathode reaction on the surfaces of the graphite electrodes is made larger than the magnitude of the current contributing to an anode reaction on the surfaces of the graphite electrodes, thereby reducing the consumption rate of the graphite electrodes.

Abstract: A method of electrolytic treatment on the surface of metal web, such as may be employed to fabricate offset printing plates supports, in which the rate of consumption of graphite electrodes used with the process is remarkably reduced. A current having asymmetric positive and negative half cycles is applied between graphite electrodes disposed in a main cell. A portion of the current of the half cycle having the larger average value is applied to an auxiliary anode electrodes provided in an independent auxiliary cell separated from the graphite electrodes. The auxiliary electrode is made of an insoluble material. By making the current density for anode reaction on the surfaces of the graphite electrodes smaller than the current density for cathode reaction on the surfaces of the graphite electrodes, the consumption rate of the graphite electrodes is greatly reduced.

Abstract: An aluminum article is protected against electrochemical corrosive attack by an aqueous medium with which the article is at least partially in contact by the steps of observing the cathodic potential of the article relative to a reference electrode in contact with the medium; when the observed cathodic potential of said article approaches the potential at which pitting corrosion of the same is initiated, electrically connecting said article directly to a source of potential electronegative with respect to the observed potential of the article to repress the cathodic potential of said article to within the alkali corrosion range; and after the cathodic potential is repressed within the alkali corrosion range, disconnecting the article from said electronegative potential source to allow the article to gradually return to its natural cathodic potential in the medium.

Abstract: The invention comprises an improved method for producing anodized aluminum articles colored by means of optical interference effects. The method comprises the steps of subjecting an aluminum article that has been anodized by conventional process to a treatment for modifying the pore structure of the anodic film, thereafter subjecting it while connected as anode to an electrolytic treatment for modifying the barrier layer between the oxide and the metal substrate and finally coloring the article while connected as cathode in an electrolyic bath containing one or more dissolved metal salts using DC current on which is superimposed a train of positive current pulses.

Abstract: Disclosed is a method of coloring an anodized and anodically reinforced aluminum or aluminum alloy article by cathodic treatment in a coloring solution wherein the cathodic electrolytic current is a negative voltage direct current having a duration substantially less than the interval therebetween and being repeated at a frequency sufficient to produce the required coloration.

Abstract: Aluminum substrates are electrograined for lithographic printing in an electrolytic cell using an electrolyte of hydrochloric acid or nitric acid, and a "regulated alternating current" whereby the inter-electrode voltage is applied with a higher anodic voltage than the cathodic voltage, the ratio of cathodic coulombic input to anodic coulombic input is less than one and preferably in the range of 0.3-0.8, and the anodic half cycle period or time is not longer than the cathodic half cycle period or time, thereby to impart to the substrate a "pits-within-a-pit" grain structure uniformly over its entire surface.