Abstract: Aluminum electrolytic capacitor anode foil of a high cubic texture etched in a two step process by treating the foil in an electrolyte bath containing 3% hydrochloric acid and 1% aluminum as aluminum chloride under the influence of a direct current and at a temperature of 75.degree. C., and in a second step treating said etched foil in an aqueous bath of 8% nitric acid and 2.6% aluminum as a nitrate at a temperature of 85.degree. C. for 5 to 7 minutes. The foil thus etched has a significantly higher capacitance resulting from a greater density of tunnels, an elongation of the tunnels, and a fairly linear tunnel structure.

Abstract: Aluminum electrolytic capacitor anode foil of a high cubic texture is etched using a two step process by treating the foil in an electrolyte bath containing 3% hydrochloric acid and 1% aluminum as aluminum chloride under the influence of a direct current of high current density and at a temperature of 75.degree. C., and in a second step treating said etched foil in a similar bath with a much lower current density and at a temperature of 80.degree. to 82.5.degree. C. The foil thus etched has a significantly higher capacitance resulting from a greater density of tunnels, and a fairly linear tunnel structure.

Abstract: Aluminum electrolytic capacitor foil of a high cubic texture etched by passing the foil through an electrolyte bath containing 3% hydrochloric acid and 1% aluminum as aluminum chloride under the influence of a direct current and at a temperature of 75.degree. C. The foil thus etched has a significantly higher capacitance resulting from a greater density of tunnels, an elongation of the tunnels, and a fairly linear tunnel structure in the foil.

Abstract: Aluminum electrolytic capacitor foil is etched by passing the foil through an electrolyte bath containing 2.5 moles/liter of sodium chloride and 0.08 to 0.48 moles/liter of boric acid or 0.05 to 0.07 moles/liter of a citrate ion source under the influence of direct current and at a temperature of 90.degree. to 95.degree. C. The foil thus etched has a central metallic core which results in improved mechanical properties.

Abstract: Aluminum capacitor foil is etched using AC current and an etchant bath comprising 0.8 to 1.5 M hydrochloric acid, 0.4 to 0.5 M aluminum chloride, 0.04 to 0.3 M nitric acid, and 0.05 to 0.2 M tartaric acid. The frequency of the alternating current is 12 to 20 Hz, and the bath temperature is 30.degree. to 40.degree. C.

Abstract: Aluminum electrolytic capacitor foil is etched in a bath containing 0.5 to 1.8 M hydrochloric acid, 0.2 to 0.5 M aluminum chloride, 0.03 to 0.3 M phosphoric acid, and 0.05 to 0.3 M nitric acid, the molar ratio of said nitric acid to said phosphoric acid being 0.3-5, while subjected to the action of alternating current at 28.degree. to 45.degree. C.

Abstract: Aluminum capacitor foil is etched in a bath at 30.degree. to 45.degree. C. containing 0.5 to 1.8 M hydrochloric acid, 0.05 to 0.3 M phosphoric acid, 0.2 to 0.5 aluminum chloride and 0.09 to 1.0 M alkali or alkaline earth metal chloride while being subjected to alternating current at 15 to 36 Hz frequency.

Abstract: Production of thin stable films of oxy-anion-substituted silver iodide solid electrolytes, such as Ag.sub.19 I.sub.15 P.sub.2 O.sub.7, on a substrate, such films having good ionic conductivity at room temperature, by vaporizing such oxy-anion-substituted silver iodide elecytrolyte material, or a mixture of the components thereof in stoichiometric proportions, by flash evaporation of such electrolyte material at high temperature, preferably ranging from about 1,400.degree. to about 1,600.degree. C., or by RF sputtering, preferably at electrode potentials ranging from about 700 to about 900 volts, and maintaining the substrate on which the solid electrolyte film is deposited, at certain elevated temperatures, preferably ranging from about 140.degree. to about 150.degree. C.

Abstract: Aluminum electrolytic capacitor foil is etched in a bath containing 0.7 to 2.0 M hydrochloric acid, 0.2 to 0.5 M hydrated aluminum trichloride, and 0.02 to 0.4 M phosphate ion while subjected to the action of alternating current at 35.degree. to 55.degree. C.