Patents Represented by Attorney James D. Griffin
  • Patent number: 4961903
    Abstract: An improved iron aluminide alloy of the DO.sub.3 type that has increased room temperature ductility and improved high elevated temperature strength. The alloy system further is resistant to corrosive attack in the environments of advanced energy corrosion systems such as those using fossil fuels. The resultant alloy is relatively inexpensive as contrasted to nickel based and high nickel steels currently utilized for structural components. The alloy system consists essentially of 26-30 at. % aluminum, 0.5-10 at. % chromium, 0.02-0.3 at. % boron plus carbon, up to 2 at. % molybdenum, up to 1 at. % niobium, up to 0.5 at. % zirconium, up to 0.1 at. % yttrium, up to 0.5 at. % vanadium and the balance iron.
    Type: Grant
    Filed: March 7, 1989
    Date of Patent: October 9, 1990
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Claudette G. McKamey, Chain T. Liu
  • Patent number: 4929328
    Abstract: An improved cathode structure for Hall-Heroult cells for the electrolytic production of aluminum metal. This cathode structure is a preform fiber base material that is infiltrated with electrically conductive titanium diboride using chemical vapor infiltration techniques. The structure exhibits good fracture toughness, and is sufficiently resistant to attack by molten aluminum. Typically, the base can be made from a mat of high purity silicon carbide fibers. Other ceramic or carbon fibers that do not degrade at temperatures below about 1000 deg. C can be used.
    Type: Grant
    Filed: March 7, 1989
    Date of Patent: May 29, 1990
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventors: Theodore M. Besmann, Richard A. Lowden
  • Patent number: 4894194
    Abstract: A method for molding ceramic powders comprises forming a slurry mixture including ceramic powder, a dispersant for the metal-containing powder, and a monomer solution. The monomer solution includes at least one multifunctional monomer, a free-radical initiator, and an organic solvent. The slurry mixture is transferred to a mold, and the mold containing the slurry mixture is heated to polymerize and crosslink the monomer and form a firm polymer-solvent gel matrix. The solid product may be removed from the mold and heated to first remove the solvent and subsequently remove the polymer, whereafter the product may be sintered.
    Type: Grant
    Filed: February 22, 1988
    Date of Patent: January 16, 1990
    Assignee: Martin Marietta Energy Systems, Inc.
    Inventor: Mark A. Janney