Patents by Inventor Sang H. Yoo

Sang H. Yoo 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: 6309591
    Abstract: An apparatus for bonding a particle material to near theoretical density, includes a chamber, a punch and die assembly for supporting a particle material, plungers for applying shear and/or axial pressures, and a power supply for applying a current. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps. is applied. The apparatus may be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: October 30, 2001
    Assignee: Materials Modification, Inc.
    Inventors: Sang H. Yoo, Krupashankara M. Sethuram, Tirumalai S. Sudarshan
  • Patent number: 6270718
    Abstract: A method of bonding a particle material to near theoretical density, includes placing a particle material in a die. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps. is applied. The method can be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material. The method may also be applied to perform combustion synthesis of a reactive material, followed by consolidation or joining to near-net shaped articles or parts.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: August 7, 2001
    Assignee: Materials Modification, Inc.
    Inventors: Sang H. Yoo, Krupashankara M. Sethuram, Tirumalai S. Sudarshan
  • Patent number: 6187087
    Abstract: A method of bonding a particle material to near theoretical density, includes placing a particle material in a die. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps. is applied. The method can be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material. The method may also be applied to perform combustion synthesis of a reactive material, followed by consolidation or joining to near-net shaped articles or parts.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: February 13, 2001
    Assignee: Materials Modification, Inc.
    Inventors: Sang H. Yoo, Krupashankara M. Sethuram, Tirumalai S. Sudarshan
  • Patent number: 6183690
    Abstract: A method of bonding a particle material to near theoretical density, includes placing a particle material in a die. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps. is applied. The method can be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material. The method may also be applied to perform combustion synthesis of a reactive material, followed by consolidation or joining to near-net shaped articles or parts.
    Type: Grant
    Filed: October 5, 1999
    Date of Patent: February 6, 2001
    Assignee: Materials Modification, Inc.
    Inventors: Sang H. Yoo, Krupashankara M. Sethuram, Tirumalai S. Sudarshan
  • Patent number: 6001304
    Abstract: A method of bonding a particle material to near theoretical density, includes placing a particle material in a die. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps, is applied. The method can be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material. The method may also be applied to perform combustion synthesis of a reactive material, followed by consolidation or joining to near-net shaped articles or parts.
    Type: Grant
    Filed: December 31, 1998
    Date of Patent: December 14, 1999
    Assignee: Materials Modification, Inc.
    Inventors: Sang H. Yoo, Krupashankara M. Sethuram, Tirumalai S. Sudarshan
  • Patent number: 5989487
    Abstract: An apparatus for bonding a particle material to near theoretical density, includes a chamber, a punch and die assembly for supporting a particle material, plungers for applying shear and/or axial pressures, and a power supply for applying a current. In the first stage, a pulsed current of about 1 to 20,000 amps., is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a shear force of about 5-50 MPa is applied. In the second stage, an axial pressure of about less than 1 to 2,000 MPa is applied to the particle material for a predetermined time period, and substantially simultaneously therewith, a steady current of about 1 to 20,000 amps. is applied. The apparatus may be used to bond metallic, ceramic, intermetallic and composite materials to near-net shape, directly from precursors or elemental particle material without the need for synthesizing the material.
    Type: Grant
    Filed: March 23, 1999
    Date of Patent: November 23, 1999
    Assignee: Materials Modification, Inc.
    Inventors: Sang H. Yoo, Krupashankara M. Sethuram, Tirumalai S. Sudarshan
  • Patent number: D307858
    Type: Grant
    Filed: February 18, 1987
    Date of Patent: May 15, 1990
    Inventor: Sang H. Yoo