Patents by Inventor Stephen L. Bennett

Stephen L. Bennett 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: 6869460
    Abstract: An eta-phase-free cemented carbide insert with improved surface hardness and wear resistance containing WC, and possibly cubic phases of a carbide and/or carbonitride, in a binder phase of Co, Ni, Fe or a combination thereof, with a binder phase gradient in the surface and near surface regions, is disclosed. The nominal binder phase content in the insert is 3-20 weight %. The surface, and near surface cobalt content is 50-100% of the binder phase content of the inner portion of the insert. The insert is formed by standard sintering practices, followed by the chemical removal of the binder phase from the surface and near surface regions of the insert. The insert is then heat treated at a temperature of 1300-1350° C. in a carburizing atmosphere, for a time of 5-400 minutes to cause diffusion of the binder phase from the interior into the binder depleted surface regions.
    Type: Grant
    Filed: September 22, 2003
    Date of Patent: March 22, 2005
    Assignee: Valenite, LLC
    Inventors: Stephen L. Bennett, Mark J. Jagner
  • Patent number: 5713133
    Abstract: Methods for producing an adherent diamond film on a cemented metal carbide substrate are disclosed. Particularly, the present invention discloses methods of preparing the surface of a cemented metal carbide surface such that an adherent polycrystalline diamond coating may be deposited thereon using CVD techniques. Cutting tool inserts produced from such adherent diamond film coated cemented metal carbide articles are also disclosed.
    Type: Grant
    Filed: June 27, 1996
    Date of Patent: February 3, 1998
    Assignee: Valenite Inc.
    Inventors: Deepak G. Bhat, Darrell Johnson, Stephen L. Bennett
  • Patent number: 5560839
    Abstract: Methods for producing an adherent diamond film on a cemented metal carbide substrate are disclosed. Particularly, the present invention discloses methods of preparing the surface of a cemented metal carbide surface such that an adherent polycrystalline diamond coating may be deposited thereon using CVD techniques. Cutting tool inserts produced from such adherent diamond film coated cemented metal carbide articles are also disclosed.
    Type: Grant
    Filed: June 27, 1994
    Date of Patent: October 1, 1996
    Assignee: Valenite Inc.
    Inventors: Stephen L. Bennett, Deepak G. Bhat, Darrell Johnson
  • Patent number: 5494635
    Abstract: Processes are disclosed in which cemented carbide parts, having a wide range of initial carbon levels, and a wide range of sizes, can be carburized to a critical carbon level, and then slow cooled at various rates, to yield stratified enriched zones in the near-surface region of said parts. The enriched zones are characterized by the cobalt content decreasing, and the microhardness increasing, continuously through the enriched zones, and approaching values characteristic of the interior. The combination of stratified enriched zones in the near surface region and the 6% binder interior provide the toughness and deformation resistance required for heavy roughing applications.A wide variety of cemented carbides, having different compositions and WC grain sizes, can also be carburized and slow cooled using the same techniques to yield stratified binder enriched zones having the same hardness profiles and cobalt content profiles as described above.
    Type: Grant
    Filed: May 20, 1993
    Date of Patent: February 27, 1996
    Assignee: Valenite Inc.
    Inventor: Stephen L. Bennett
  • Patent number: 5310605
    Abstract: A process for producing a ceramic-metal composite body exhibiting binder enrichment and improved fracture toughness at its surface. The process involves forming a shaped body from a homogeneous mixture of: (a) about 2-15 w/o Co or about 2-12 w/o Ni binder, (b) excess carbon, (c) optionally, 0 to less than 5.0 v/o B-1 carbides, and (d) remainder tungsten carbide. The mixture contains sufficient total carbon to result in an ASTM carbon porosity rating of C06 to C08 at the core of the densified body. The weight ratio of excess carbon to binder is about 0.05:1 to 0.037:1. The shaped body is densified in a vacuum or inert atmosphere at or above about 1300.degree. C. and slow cooled, at least to about 25.degree. below the eutectic temperature. Alternatively, the sintered body may be cooled to a holding temperature at or slightly above the eutectic temperature, isothermally held for at least 1/2 hr, and further cooled to ambient.
    Type: Grant
    Filed: August 25, 1992
    Date of Patent: May 10, 1994
    Assignee: Valenite Inc.
    Inventors: J. Gary Baldoni, II, Stephen L. Bennett