Patents by Inventor Wayne S. Steffier

Wayne S. Steffier 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: 5221578
    Abstract: A ceramic fiber/ceramic matrix composite has ceramic fibers and a porous coating on the fibers. A ceramic matrix contacts the porous coating, the fiber and coating being immersed in the ceramic matrix. The porous coating is selected from the group including Si.sub.3 N.sub.4, SiC, ZrO.sub.2, Al.sub.2 O.sub.3, SnO.sub.2 and Ta.sub.2 O.sub.5. The pores are generally empty so as to render the coating frangible to promote fiber de-bonding and pull-out in the wake of an advancing crack in the matrix. In order to keep the pores empty, a non-porous sealing layer is formed over the porous coating which closes the pores without filling them. The ceramic matrix remains generally outside of the pores, whereby said pores remain empty after the fiber and coating are immersed in the ceramic matrix.
    Type: Grant
    Filed: March 13, 1991
    Date of Patent: June 22, 1993
    Assignee: Northrop Corporation
    Inventors: Harry W. Carpenter, James W. Bohlen, Wayne S. Steffier
  • Patent number: 5162271
    Abstract: A method of toughening a fiber/matrix ceramic composite consisting of non-oxide based ceramic fibers immersed in a ceramic matrix. The method includes, prior to immersing the fibers in the matrix, applying a metallo-organic solution of a noble metal to the fibers to form a coating of the solution on the fibers, evaporating the solvent from the solution and oxidizing the residual organic compounds whereby the coating becomes a pure noble metal and immersing the coated fibers in the matrix. The applying, evaporating, oxidizing and immersing steps are characterized by a limited raising of the temperature of the fibers. The coating is ductile so as to blunt advancing cracks in the matrix.
    Type: Grant
    Filed: March 13, 1991
    Date of Patent: November 10, 1992
    Assignee: Northrop Corporation
    Inventors: Harry W. Carpenter, James W. Bohlen, Wayne S. Steffier