Passivation of tantalum and other metal powders using oxygen
AssigneeCabot Corporation
InventorSridhar Venigalla
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Abstract
A method to passivate a metal or metal oxide or metal suboxide powder, especially a valve metal powder such as tantalum or niobium and the passivated powders formed therefrom are described. The method includes passivating a starting powder with a gas having at least 25 wt. % oxygen present. Passivation is preferably achieved without performing any evacuation steps. Capacitors made from the passivated powders are also described.
Claims21
A method to passivate a powder comprising passivating said powder with a gas having at least 25 wt. % oxygen present to form a passivated powder, wherein said powder is tantalum powder, niobium powder, or niobium suboxide powder, and wherein said powder has a BET surface area of from 0.2 to 40 m2/g, and a capacitance capability of from 10,000 to 400,000 CV/g.
Dependencies are inferred from the claim text.