Abstract: A method of protecting metals from corrosion by applying an alternating voltage to them, thereby reversing the metal's polarity with respect to its surroundings. Particular applications are for metals which are buried in soil or are exposed to an electrolyte. Amphoteric metals Steels, which are subject to hydrogen embrittlement when made cathodic, are also protected by polarity reversal.

Abstract: The present invention is directed to a substrate with a coating of titanium suboxide thereon. The coating protects the substrate from corrosion. Typically, the substrate is a current collector for a lead acid battery. The present invention is also directed to a process for forming the coating of titanium suboxide coating on the substrate. A colloidal dispersion of titanium suboxide particles in water is formed. The pH of the colloidal dispersion is brought within the range of 3 or less. The substrate to be coated is then placed in the colloidal dispersion. A positive electrode is also placed in the colloidal dispersion. An electric field is then introduced into the colloidal dispersion to effect electrophoretic deposition of the titanium suboxide on the substrate.

Abstract: The present invention provides improved processes for forming anti-corrosion layers, particularly barium metaplumbate, on lead, lead alloy-, and lead oxide-containing substrates. The processes of the invention are used to form corrosion-resistant current collectors which are assembled into lead-acid batteries. The inventive methods used to form barium metaplumbate employ a salt solution which includes a barium compound and a solvent salt. In a first embodiment, a substrate material having at least a surface comprising elemental lead reacts with a salt solution to form barium metaplumbate. The salt solution includes a barium compound and an oxidizing agent. The solvent salt or barium compound may themselves be oxidizing agents, or an additional oxidant may be added to the solution. The molten salt solution is applied to the substrate in any known manner such as dipping, spraying, and brushing.