Patents by Inventor Rohith Shivanath

Rohith Shivanath 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: 11465209
    Abstract: A densified, high-strength metallic component is manufactured by: binder jet additive manufacture (BJAM) printing a powder blend to form a printed part; and super solidus sintering the printed part to form the metallic component, which may then be heat treated. The powder blend comprises a blend of water atomized base iron powder and a high-carbon master ferroalloy powder. The high-carbon ferroalloy powder introduces high concentrations of carbon into a powder blend that is readily BJAM printable.
    Type: Grant
    Filed: May 9, 2019
    Date of Patent: October 11, 2022
    Assignee: Stackpole International Powder Metal LLC
    Inventors: Rohith Shivanath, Peng Shen, Vincent Williams
  • Patent number: 11114677
    Abstract: An interconnector for a solid oxide fuel cell is manufactured by single-press compacting a powder blend to form a green interconnector with a desired shape of a final interconnector. The powder blend includes chromium and iron, and may include an organic lubricant. At least 50 wt % or more of an iron portion of the powder blend comprises iron particles smaller than 45 um. The green interconnector is then sintered and oxidized to form the final interconnector. The oxidation step occurs in a continuous flow furnace in which a controlled atmosphere (e.g., humidified air) is fed into the furnace in the travel direction of the interconnector. The final interconnector comprises at least 90 wt % chromium, at least 3 wt % iron, and less than 0.2 wt % nitrogen. An average density within a flow field of the final interconnector may be less than 6.75 g/cc.
    Type: Grant
    Filed: July 8, 2013
    Date of Patent: September 7, 2021
    Assignee: Stackpole International Powder Metal, ULC
    Inventors: Roger Lawcock, Brendan Ayre, Rohith Shivanath
  • Publication number: 20190344344
    Abstract: A densified, high-strength metallic component is manufactured by: binder jet additive manufacture (BJAM) printing a powder blend to form a printed part; and super solidus sintering the printed part to form the metallic component, which may then be heat treated. The powder blend comprises a blend of water atomized base iron powder and a high-carbon master ferroalloy powder. The high-carbon ferroalloy powder introduces high concentrations of carbon into a powder blend that is readily BJAM printable.
    Type: Application
    Filed: May 9, 2019
    Publication date: November 14, 2019
    Inventors: Rohith SHIVANATH, Peng SHEN, Vincent WILLIAMS
  • Patent number: 9993874
    Abstract: A chromium-iron interconnect includes at least one of Fe rich regions in the interconnect and carbon in the interconnect.
    Type: Grant
    Filed: February 24, 2015
    Date of Patent: June 12, 2018
    Assignees: BLOOM ENERGY CORPORATION, STACKPOLE INTERNATIONAL POWDER METAL, ULC
    Inventors: Rohith Shivanath, Brendan Ayre, Tad Armstrong, Michael Gasda, Daniel Darga, Harald Herchen, Chockkalingam Karuppaiah, Brandon Dawson, Ravi Oswal
  • Publication number: 20150244004
    Abstract: A chromium-iron interconnect includes at least one of Fe rich regions in the interconnect and carbon in the interconnect.
    Type: Application
    Filed: February 24, 2015
    Publication date: August 27, 2015
    Inventors: Rohith SHIVANATH, Brendan AYRE, Tad ARMSTRONG, Michael GASDA, Daniel DARGA, Harald HERCHEN, Chockkalingam KARUPPAIAH, Brandon DAWSON, Ravi OSWAL
  • Publication number: 20150207154
    Abstract: An interconnector for a solid oxide fuel cell is manufactured by single-press compacting a powder blend to form a green interconnector with a desired shape of a final interconnector. The powder blend includes chromium and iron, and may include an organic lubricant. At least 50 wt % or more of an iron portion of the powder blend comprises iron particles smaller than 45 um. The green interconnector is then sintered and oxidized to form the final interconnector. The oxidation step occurs in a continuous flow furnace in which a controlled atmosphere (e.g., humidified air) is fed into the furnace in the travel direction of the interconnector. The final interconnector comprises at least 90 wt % chromium, at least 3 wt % iron, and less than 0.2 wt % nitrogen. An average density within a flow field of the final interconnector may be less than 6.75 g/cc.
    Type: Application
    Filed: July 8, 2013
    Publication date: July 23, 2015
    Inventors: Rohith Shivanath, Brendan Ayre, Roger Lawcock
  • Patent number: 8231827
    Abstract: A method of manufacturing powder metal plates comprising feeding a predetermined mass of metal powder onto a moving tape (101), restricting the metal powder by surrounding the metal powder with vibrating boundary walls (201, 202) extending parallel to the direction of movement of the tape, rolling the metal powder at an ambient temperature to form a green compact strip (GS), continuously sintering the green compact strip in a furnace (400), forming the green compact strip to a net shape part (NS) while in the furnace, and cooling the net shape part in a non-oxidizing environment (404) at a temperature in excess of 1000 degrees Celsius.
    Type: Grant
    Filed: June 17, 2009
    Date of Patent: July 31, 2012
    Assignee: The Gates Corporation
    Inventors: Yahya Hodjat, Roger Lawcock, Rohith Shivanath
  • Publication number: 20100322811
    Abstract: A method of manufacturing powder metal plates comprising feeding a predetermined mass of metal powder onto a moving tape (101), restricting the metal powder by surrounding the metal powder with vibrating boundary walls (201, 202) extending parallel to the direction of movement of the tape, rolling the metal powder at an ambient temperature to form a green compact strip (GS), continuously sintering the green compact strip in a furnace (400), forming the green compact strip to a net shape part (NS) while in the furnace, and cooling the net shape part in a non-oxidizing environment (404) at a temperature in excess of 1000 degrees Celsius.
    Type: Application
    Filed: June 17, 2009
    Publication date: December 23, 2010
    Inventors: Yahya Hodjat, Roger Lawcock, Rohith Shivanath
  • Patent number: 6365094
    Abstract: A toolset for forming a component from a powdered metal charge includes a die having two zones on the sidewall. Lubricant is applied to one of the zones. The powdered metal charge is initially compressed to an intermediate density and the lubricated zone of the sidewall brought into contact with the partially compressed charge. The charge is then further compressed to a final density.
    Type: Grant
    Filed: January 31, 2000
    Date of Patent: April 2, 2002
    Assignee: Stackpole Limited
    Inventors: Gerd Hinzmann, Karol Kucharski, Rohith Shivanath
  • Patent number: 6346213
    Abstract: A process of forming a sintered article of powder metal comprising blending graphite, Si carbide and lubricant, with pre-alloyed iron base powder; pressing said blended mixture to a shaped article; sintering said article in a reduced atmosphere; forced cooling said sintered article.
    Type: Grant
    Filed: November 29, 1999
    Date of Patent: February 12, 2002
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Karol Kucharski, Peter Jones
  • Patent number: 6019937
    Abstract: A process of forming a sintered article of powder metal comprising blending graphite, Si carbide and lubricant, with pre-alloyed iron base powder; pressing said blended mixture to a shaped article; sintering said article in a reduced atmosphere; forced cooling said sintered article.
    Type: Grant
    Filed: November 27, 1998
    Date of Patent: February 1, 2000
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Karol Kucharski, Peter Jones
  • Patent number: 5884527
    Abstract: A gear wheel is formed from a pressed and sintered powder metal blank in which the metal powder comprises an admixture of iron powder and at least one alloying addition and the gear wheel is surface hardened by applying densifying pressure only to the tooth root regions or only to the tooth flank regions in order to establish densification in the range of 90 to 100 per cent of full theoretical density to a depth of at least 380 and up to about 1,000 microns.
    Type: Grant
    Filed: September 4, 1997
    Date of Patent: March 23, 1999
    Assignee: Formflo Limited
    Inventors: Christopher John Cole, Rohith Shivanath, Peter Jones
  • Patent number: 5881354
    Abstract: A method of making a sintered article of powder metal having a carbon composition in the range of about 0.8% to 2.0% by weight, then spheroidizing the sintered article and then warm forming the sintered article at a temperature between 250.degree. and 700.degree. C. for a time duration selected to form the article to a final shape.
    Type: Grant
    Filed: May 3, 1996
    Date of Patent: March 9, 1999
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Peter Jones
  • Patent number: 5834640
    Abstract: This invention relates to a method or process of forming a sintered article of powder metal, and particularly relates to a process of forming a sintered article of powder metal by blending combinations of finely ground ferro alloys (either singly or in combination with other ferro alloys) with elemental iron powder and other additives and then high temperature sintering of the article in a reducing atmosphere to produce sintered parts with oxygen contents less than 250 parts per million (ppm). More particularly the ferro alloys admixed to the base iron have a mean particle size of approximately 8 to 12 microns, having previously been ground to size in an inert atmosphere.
    Type: Grant
    Filed: August 10, 1995
    Date of Patent: November 10, 1998
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Peter Jones
  • Patent number: 5729822
    Abstract: A powder metal gear wheel having a core density of at least 7.3 g/cc, and in one embodiment 7.4 to 7.6 g/cc and a hardened carburized surface. A method of manufacturing transmission gears comprises, sintering a powder metal blank to produce a core density of between 7.4 to 7.6 g/cc, rolling the surface of the gear blank to densify the surface, and then heating the rolled sintered part and carburizing in a vacuum furnace.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: March 17, 1998
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Peter Jones
  • Patent number: 5711187
    Abstract: A gear wheel is formed from a pressed and sintered powder metal blank in which the metal powder comprises an admixture of iron powder and at least one alloying addition and the gear wheel is surface hardened by densifying at least the tooth root and flank regions to establish densification in the range of 90 to 100 percent of full theoretical density to a depth of at least 380 and up to about 1,000 microns.
    Type: Grant
    Filed: January 3, 1995
    Date of Patent: January 27, 1998
    Assignee: Formflo Ltd.
    Inventors: Christopher John Cole, Rohith Shivanath, Peter Jones
  • Patent number: 5656787
    Abstract: A process of forming a sintered article for powder metal comprising blending carbon and ferro alloys and lubricant with compressible elemental iron powder, pressing said blended mixture to form sintering said article, and then high temperature sintering said article in a reducing atmosphere to produce a sintered article having a high density from a single compression.
    Type: Grant
    Filed: November 21, 1995
    Date of Patent: August 12, 1997
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Peter Jones, Danny Thien Duc Thieu
  • Patent number: 5641922
    Abstract: This invention relates to a process of forming a sintered article of powder metal comprising blending graphite and lubricant with a pre-alloyed iron based powder, pressing said blended mixture to shape in a single compaction stage sintering said article, and then high temperature sintering said article in a reducing atmosphere to produce a sintered article having a density greater than 7.4 g/cc.
    Type: Grant
    Filed: June 24, 1996
    Date of Patent: June 24, 1997
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Peter Jones, Danny Thien Duc Thieu
  • Patent number: 5552109
    Abstract: This invention relates to a process of forming a sintered article of powder metal comprising blending graphite and lubricant with a pre-alloyed iron based powder, pressing said blended mixture to shape in a single compaction stage sintering said article, and then high temperature sintering said article in a reducing atmosphere to produce a sintered article having a density greater than 7.4 g/cc.
    Type: Grant
    Filed: June 29, 1995
    Date of Patent: September 3, 1996
    Inventors: Rohith Shivanath, Peter Jones, Danny T. D. Thieu
  • Patent number: 5516483
    Abstract: A process of forming a sintered article for powder metal comprising blending carbon and ferro alloys and lubricant with compressible elemental iron powder, pressing said blended mixture to form sintering said article, and then high temperature sintering said article in a reducing atmosphere to produce a sintered article having a high density from a single compression.
    Type: Grant
    Filed: February 8, 1994
    Date of Patent: May 14, 1996
    Assignee: Stackpole Limited
    Inventors: Rohith Shivanath, Peter Jones, Danny T. D. Thieu