Patents by Inventor Bhamidipaty K. D. P. Rao

Bhamidipaty K. D. P. Rao has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 7144546
    Abstract: Nitrided valve metals are described, such as nitrided tantalum and nitrided niobium. The nitrided valve metals preferably have improved flow properties, higher Scott Densities, and/or improved pore size distribution which leads to improved physical properties of the valve metal and improved electrical properties once the valve metal is formed into a capacitor anode. Processes for preparing a nitrided valve metal are further described and involve nitriding the valve metal at a sufficient temperature and pressure during a heat treatment that is prior to the deoxidation step. Capacitor anodes and other products incorporating the valve metals of the present invention are further described.
    Type: Grant
    Filed: November 25, 2003
    Date of Patent: December 5, 2006
    Assignee: Cabot Corporation
    Inventors: Shi Yuan, legal representative, Bhamidipaty K. D. P. Rao, deceased
  • Publication number: 20040108018
    Abstract: Nitrided valve metals are described, such as nitrided tantalum and nitrided niobium. The nitrided valve metals preferably have improved flow properties, higher Scott Densities, and/or improved pore size distribution which leads to improved physical properties of the valve metal and improved electrical properties once the valve metal is formed into a capacitor anode. Processes for preparing a nitrided valve metal are further described and involve nitriding the valve metal at a sufficient temperature and pressure during a heat treatment that is prior to the deoxidation step. Capacitor anodes and other products incorporating the valve metals of the present invention are further described.
    Type: Application
    Filed: November 25, 2003
    Publication date: June 10, 2004
    Inventors: Bhamidipaty K.D.P. Rao, Shi Yuan
  • Patent number: 6679934
    Abstract: Nitrided valve metals are described, such as nitrided tantalum and nitrided niobium. The nitrided valve metals preferably have improved flow properties, higher Scott Densities, and/or improved pore size distribution which leads to improved physical properties of the valve metal and improved electrical properties once the valve metal is formed into a capacitor anode. Processes for preparing a nitrided valve metal are further described and involve nitriding the valve metal at a sufficient temperature and pressure during a heat treatment that is prior to the deoxidation step. Capacitor anodes and other products incorporating the valve metals of the present invention are further described.
    Type: Grant
    Filed: February 28, 2001
    Date of Patent: January 20, 2004
    Assignee: Cabot Corporation
    Inventors: Bhamidipaty K. D. P. Rao, Shi Yuan
  • Publication number: 20030115985
    Abstract: A method to agglomerate metal particles such as tantalum and niobium powders is described which includes combining a volatilizable or vaporizable liquid with the particles to form wet particles; compacting the wet particles; drying the compacted wet particles to form a cake; and heat treating the cake to form the agglomerated particles. Also described are agglomerated particles obtained by this method and further, particles, preferably tantalum or niobium powder, having a flow rate of at least about 65 mg/sec and/or an improved pore size distribution, and/or a higher Scott Density. Capacitors made from tantalum powder and niobium powder are also described.
    Type: Application
    Filed: November 7, 2002
    Publication date: June 26, 2003
    Inventor: Bhamidipaty K. D. P. Rao
  • Patent number: 6576038
    Abstract: A method to agglomerate metal particles such as tantalum and niobium powders is described which includes combining a volatilizable or vaporizable liquid with the particles to form wet particles; compacting the wet particles; drying the compacted wet particles to form a cake; and heat treating the cake to form the agglomerated particles. Also described are agglomerated particles obtained by this method and further, particles, preferably tantalum or niobium powder, having a flow rate of at least about 65 mg/sec and/or an improved pore size distribution, and/or a higher Scott Density. Capacitors made from tantalum powder and niobium powder are also described.
    Type: Grant
    Filed: May 19, 1999
    Date of Patent: June 10, 2003
    Assignee: Cabot Corporation
    Inventor: Bhamidipaty K. D. P. Rao
  • Patent number: 6479012
    Abstract: A method to agglomerate metal particles such as tantalum and niobium powders is described which includes combining a volatilizable or vaporizable liquid with the particles to form wet particles; compacting the wet particles; drying the compacted wet particles to form a cake; and heat treating the cake to form the agglomerated particles. Also described are agglomerated particles obtained by this method and further, particles, preferably tantalum or niobium powder, having a flow rate of at least about 65 mg/sec and/or an improved pore size distribution, and/or a higher Scott Density. Capacitors made from tantalum powder and niobium powder are also described.
    Type: Grant
    Filed: August 2, 2001
    Date of Patent: November 12, 2002
    Assignee: Cabot Corporation
    Inventor: Bhamidipaty K. D. P. Rao
  • Publication number: 20020033072
    Abstract: A method to agglomerate metal particles such as tantalum and niobium powders is described which includes combining a volatilizable or vaporizable liquid with the particles to form wet particles; compacting the wet particles; drying the compacted wet particles to form a cake; and heat treating the cake to form the agglomerated particles. Also described are agglomerated particles obtained by this method and further, particles, preferably tantalum or niobium powder, having a flow rate of at least about 65 mg/sec and/or an improved pore size distribution, and/or a higher Scott Density. Capacitors made from tantalum powder and niobium powder are also described.
    Type: Application
    Filed: August 2, 2001
    Publication date: March 21, 2002
    Inventor: Bhamidipaty K. D. P. Rao
  • Patent number: 5986877
    Abstract: A capacitor having a central electrode body having sintered metal anode with an electrode lead, the anode having a sintered product produced from a tantalum powder having deagglomerated particles such that the product of the volume mean diameter in microns multiplied by the specific surface area measured in m.sup.2 /g is a number in the range of below about 25. Capacitors having a central electrode with the anode produced from a sintered product produced from a heat treated and oxidized tantalum powder wherein the oxidized particle size is greater than about 0.7 m.sup.2 /g. Capacitors are defined in terms of anodes produced from powders having specified ratios of Scott Bulk Density to surface area or ratio of die fill rate to surface area.
    Type: Grant
    Filed: July 28, 1998
    Date of Patent: November 16, 1999
    Assignee: Cabot Corporation
    Inventors: Viren M. Pathare, Bhamidipaty K. D. P. Rao, James Allen Fife, Hongju Chang, Roger W. Steele, Lee M. Ruch
  • Patent number: 5954856
    Abstract: A process for sizing (i.e., comminuting) a tantalum powder including agglomerates of smaller particles, which process yields a tantalum powder having an as-comminuted agglomerate size distribution with the product of the Volume Mean Diameter, MV (in microns as measured by light scattering techniques such as Microtrac analysis), times specific surface area, BET (m.sup.2 /g), being less than about 25. These powders after sizing typically have ratios of Scott Bulk Density : BET Surface Area in the range from about 20 to about 35. Also provided are powders having a substantially unimodal and narrow agglomerate size distribution in all stages of production, namely after sizing (i.e., deagglomeration by comminution), thermal agglomeration (i.e., heat treatment), and deoxidation. These resultant powders have high surface area and good flowability properties and, upon sintering, exhibit controlled shrinkage with high porosity.
    Type: Grant
    Filed: April 25, 1996
    Date of Patent: September 21, 1999
    Assignee: Cabot Corporation
    Inventors: Viren M. Pathare, Bhamidipaty K. D. P. Rao, James Allen Fife, Hongju Chang, Roger W. Steele, Lee M. Ruch