Patents by Inventor Mark E. Pfaff

Mark E. Pfaff 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: 5976429
    Abstract: A dense, self-sintered silicon carbide/carbon-graphite composite material and a process for producing the composite material. The composite material includes a silicon carbide matrix, between 2 and 30 percent by weight carbon-graphite, and small amounts of sintering aids such as boron and free carbon. The silicon carbide has an average grain size between 2 and 15 .mu.m, and the carbon-graphite has an average grain size between 10 and 75 .mu.m, the average grain size of the carbon-graphite being greater than the average grain size of the silicon carbide. The composite material has a density of at least 80 percent of theoretical density as determined by the rule of mixtures for a composite material. This density is achieved with minimal microcracking at a high graphite loading with large graphite particles. The composite material exhibits good lubricity and wear characteristics, resulting in improved tribological performance.
    Type: Grant
    Filed: November 7, 1994
    Date of Patent: November 2, 1999
    Assignee: The Morgan Crucible Company, PLC
    Inventors: Xin E. Chen, Mark E. Pfaff
  • Patent number: 5968653
    Abstract: A carbon-graphite/silicon carbide composite article is provided. The composite article includes a carbon-graphite body intimately bonded to a dense silicon carbide body by a transition/bonding region which links the two bodies. The transition/bonding region between the carbon-graphite body and the silicon carbide body typically includes a layer rich in silicon metal and a small silicon carbide/silicon metal/carbon graphite area where some of the carbon-graphite from the carbon-graphite body has been converted to silicon carbide. The carbon-graphite body may also include a variety of impregnants.
    Type: Grant
    Filed: January 11, 1996
    Date of Patent: October 19, 1999
    Assignee: The Morgan Crucible Company, plc
    Inventors: Steven J. Coppella, Laurence J. Thorwart, Mark E. Pfaff, David A. Erich
  • Patent number: 5707567
    Abstract: A self-sintered silicon carbide/carbon-graphite composite material having interconnected pores which may be impregnated, and a raw batch and process for producing the composite material, is provided. The composite material comprises a densified, self-sintered matrix of silicon carbide, carbon-graphite inclusions and small amounts of any residual sintering aids, such as boron and free carbon, and has interconnected pores which may be impregnated with resin, carbon, TEFLON, (polyetrafluoroethylene) metal or other compounds or materials selected for their particular properties to achieve desired tribological characteristics for a specific application. The composite material is produced from a raw batch which includes silicon carbide, sintering aids, a temporary filler and coated graphite particles. The raw batch is then molded/shaped into a green body and heated to carbonize any carbonizable materials and to decompose and volatilize the organic filler to form a matrix of interconnected pores.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: January 13, 1998
    Assignee: The Morgan Crucible Company PLC
    Inventor: Mark E. Pfaff
  • Patent number: 5656563
    Abstract: A dense, self-sintered silicon carbide/carbon-graphite composite material and a process for producing the composite material is disclosed. The composite material comprises a silicon carbide matrix, between 2 and 30 percent by weight carbon-graphite, and small amounts of sintering aids such as boron and free carbon. The silicon carbide has an average grain size between 2 and 15 .mu.m, and the carbon-graphite has an average grain size between 10 and 75 .mu.m, the average grain size of the carbon-graphite being greater than the average grain size of the silicon-carbide. The composite material has a density of at least 80 percent of theoretical density as determined by the rule of mixtures for a composite material. This density is achieved with minimal microcracking at a high graphite loading with large graphite particles. The composite material exhibits good lubricity and wear characteristics, resulting in improved tribological performance.
    Type: Grant
    Filed: June 2, 1995
    Date of Patent: August 12, 1997
    Assignee: The Morgan Crucible Company plc
    Inventors: Xin E. Chen, Mark E. Pfaff
  • Patent number: 5580834
    Abstract: A self-sintered silicon carbide/carbon-graphite composite material having interconnected pores which may be impregnated, and a raw batch and process for producing the composite material, is provided. The composite material comprises a densified, self-sintered matrix of silicon carbide, carbon-graphite inclusions and small amounts of any residual sintering aids, such as boron and free carbon, and has interconnected pores which may be impregnated with resin, carbon, TEFLON, metal or other compounds or materials selected for their particular properties to achieve desired tribological characteristics for a specific application. The composite material is produced from a raw batch which includes silicon carbide, sintering aids, a temporary filler and coated graphite particles. The raw batch is then molded/shaped into a green body and heated to carbonize any carbonizable materials and to decompose and volatilize the organic filler to form a matrix of interconnected pores.
    Type: Grant
    Filed: February 25, 1994
    Date of Patent: December 3, 1996
    Assignee: The Morgan Crucible Company plc
    Inventor: Mark E. Pfaff
  • Patent number: 5422322
    Abstract: A dense, self-sintered silicon carbide/carbon-graphite composite material and a process for producing the composite material is disclosed. The composite material comprises a silicon carbide matrix, between 2 and 30 percent by weight carbon-graphite, and small amounts of sintering aids such as boron and free carbon. The silicon carbide has an average grain size between 2 and 15 .mu.m, and the carbon-graphite has an average grain size between 10 and 75 .mu.m, the average grain size of the carbon-graphite being greater than the average grain size of the silicon carbide. The composite material has a density of at least 80 percent of theoretical density as determined by the rule of mixtures for a composite material. This density is achieved with minimal microcracking at a high graphite loading with large graphite particles. The composite material exhibits good lubricity and wear characteristics, resulting in improved tribological performance.
    Type: Grant
    Filed: February 10, 1993
    Date of Patent: June 6, 1995
    Assignee: The Stackpole Corporation
    Inventors: Xin E. Chen, Mark E. Pfaff