Patents by Inventor Narottam P. Bansal

Narottam P. Bansal 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).

  • Multilayer article having stabilized zirconia outer layer and chemical barrier layer
    Patent number: 6733908
    Abstract: A multilayer article includes a substrate that includes at least one of a ceramic compound and a Si-containing metal alloy. An outer layer includes stabilized zirconia. Intermediate layers are located between the outer layer and the substrate and include a mullite-containing layer and a chemical barrier layer. The mullite-containing layer includes 1) mullite or 2) mullite and an alkaline earth metal aluminosilicate. The chemical barrier layer is located between the mullite-containing layer and the outer layer. The chemical barrier layer includes at least one of mullite, hafnia, hafnium silicate and rare earth silicate (e.g., at least one of RE2SiO5 and RE2Si2O7 where RE is Sc or Yb). The multilayer article is characterized by the combination of the chemical barrier layer and by its lack of a layer consisting essentially of barium strontium aluminosilicate between the mullite-containing layer and the chemical barrier layer.
    Type: Grant
    Filed: July 8, 2002
    Date of Patent: May 11, 2004
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Kang N. Lee, Narottam P. Bansal
  • Silicon based substrate with environmental/thermal barrier layer
    Patent number: 6387456
    Abstract: A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a barium-strontium alumino silicate.
    Type: Grant
    Filed: September 5, 2000
    Date of Patent: May 14, 2002
    Assignees: General Electric Company, United Technologies Corporation, The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Harry Edwin Eaton, Jr., William Patrick Allen, Nathan S. Jacobson, Narottam P. Bansal, Elizabeth J. Opila, James L. Smialek, Kang N. Lee, Irene T. Spitsberg, Hongyu Wang, Peter Joel Meschter, Krishan Lal Luthra
  • Method of producing a silicon carbide fiber reinforced strontium aluminosilicate glass-ceramic matrix composite
    Patent number: 5389321
    Abstract: A SrO-Al.sub.2 O.sub.3 -2SrO.sub.2 (SAS) glass ceramic matrix is reinforced with CVD SiC continuous fibers. This material is prepared by casting a slurry of SAS glass powder into tapes. Mats of continuous CVD-SiC fibers are alternately stacked with the matrix tapes.This tape-mat stack is warm-pressed to produce a "green" composite. Organic constituents are burned out of the "green" composite, and the remaining interim material is hot pressed.
    Type: Grant
    Filed: September 16, 1993
    Date of Patent: February 14, 1995
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Narottam P. Bansal
  • Method of producing a ceramic fiber-reinforced glass-ceramic matrix composite
    Patent number: 5281559
    Abstract: A fiber-reinforced composite composed of a B.sub.a O--Al.sub.2 O.sub.3 --2SiO.sub.2 (BAS) glass ceramic matrix is reinforced with CVD silicon carbide continuous fibers. A slurry of BAS glass powders is prepared and celsian seeds are added during ball melting. The slurry is cast into tapes which are cut to the proper size.Continuous CVD-SiC fibers are formed into mats of the desired size. The matrix tapes and the fiber mats are alternately stacked in the proper orientation. This tape-mat stack is warm pressed to produce a "green" composite.The "green" composite is then heated to an elevated temperature to burn out organic constituents. The remaining interim material is then hot pressed to form a silicon carbide fiber-reinforced celsian (BAS) glass-ceramic matrix composite which may be machined to size.
    Type: Grant
    Filed: June 30, 1993
    Date of Patent: January 25, 1994
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Narottam P. Bansal
  • Sintering silicon nitride
    Patent number: 5256610
    Abstract: Oxides having a composition of (Ba.sub.1-x Sr.sub.x)O--Al.sub.2 O.sub.3 --2SiO.sub.2 are used as sintering aids for producing an improved silicon nitride ceramic material. The x must be greater than 0 to insure the formation of the stable monoclinic celsian glass phase.
    Type: Grant
    Filed: November 27, 1992
    Date of Patent: October 26, 1993
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventors: Narottam P. Bansal, Stanley R. Levine, William A. Sanders
  • Ceramic fiber reinforced glass-ceramic matrix composite
    Patent number: 5214004
    Abstract: A slurry of BSAS glass powders is cast into tapes which are cut to predetermined sizes. Mats of continuous CVD-SiC fibers are alternately stacked with these matrix tapes. This tape-mat stack is warm-pressed to produce a "green" composite which is heated to burn out organic constituents The remaining interim material is then hot-pressed to form a BSAS glass-ceramic fiber-reinforced composite.
    Type: Grant
    Filed: June 4, 1992
    Date of Patent: May 25, 1993
    Assignee: The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
    Inventor: Narottam P. Bansal