Abstract: A method of anodizing valve metals with a borate polyester solution formed by the combining 2-methyl-1,3-propane diol and boric acid and heating to about 130 to about 160° C. The heating drives off water produced by esterification. A substrate is immersed in the borate polyester electrolyte solution at a temperature of about 25° C. to about 85° C. and an anodizing voltage is applied.

Abstract: Organic acid-based binders are efficiently removed from powder metallurgy compacts, such as tantalum capacitor anode bodies, by immersion in a heated aqueous alkanolamine solution followed by rinsing in warm water. This method results in lower residual carbon and oxygen levels than are found with thermal binder removal methods.

Abstract: Metal powders are pressed into compacts more readily through the addition of a minor percentage of dimethyl sulfone binder. Dimethyl sulfone may be dry-blended with the metal powder by mixing it in the form of a powder, or it may be wet-blended by first dissolving it in a suitable solvent, then adding it to the metal powder and evaporating the solvent. Dimethyl sulfone may be almost completely removed from compacts pressed from tantalum, etc., either by vacuum distillation or by water leaching, to leave compacts uncontaminated by the binder and suitable for further processing into capacitor anodes, etc.

Abstract: A method of non-thickness-limited anodizing for valve metals and alloys which are resistant to the non-thickness-limited growth of anodic oxide, such as niobium and high niobium content alloys. Non-thickness-limited anodic oxide film growth is produced on such valve metals by employing a first glycerine-based electrolyte containing about 1 to about 3 wt % water for the initial production of anodic oxide. After the substrate is anodized using the first electrolyte, it is immersed in a second glycerine-based electrolyte having less than about 0.1 wt % water. The second electrolyte may be produced by allowing water to evaporate from the first electrolyte solution until the solution contains less than about 0.1 wt. % water.

Abstract: Metal powders are pressed into compacts more readily through the addition of a minor percentage of dimethyl sulfone binder. Dimethyl sulfone may be dry-blended with the metal powder by mixing it in the form of a powder, or it may be wet-blended by first dissolving it in a suitable solvent, then adding it to the metal powder and evaporating the solvent. Dimethyl sulfone may be almost completely removed from compacts pressed from tantalum, etc., either by vacuum distillation or by water leaching, to leave compacts uncontaminated by the binder and suitable for further processing into capacitor anodes, etc.

Abstract: Capacitor elements made with a solid polymeric electrolyte show reduced leakage current when reformed at about 60-85% of formation voltage during the impregnation phase between successive layers of polymeric electrolyte.

Abstract: An anodizing electrolyte containing a polyethylene glycol dimethyl ether and an electrochemical process for anodizing valve metals which permits the formulation of an anodic layer having a substantially uniform thickness and reduced flaw density.