Patents by Inventor Srinivasan Shankar

Srinivasan Shankar 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: 6444054
    Abstract: Slurry coating compositions are provided for metal substrates, particularly nickel or cobalt-containing alloys, that enable inward-type diffusion aluminide coatings having a substantially uniform coating thickness to be formed thereon. Substantially uniform coating thicknesses are achieved independent of applied slurry composition thickness or application method. The slurry coating composition of the invention comprises a Cr—Al alloy containing about 50 wt % to about 80 wt % Cr in the alloy, LiF in an amount greater than or equal to 0.3 wt % of the Cr—Al alloy, an organic binder, and a solvent.
    Type: Grant
    Filed: June 21, 2000
    Date of Patent: September 3, 2002
    Assignee: Sermatech International, Inc.
    Inventors: Thomas Kircher, Bruce G. McMordie, Srinivasan Shankar
  • Patent number: 6110262
    Abstract: Slurry coating compositions are provided for metal substrates, particularly nickel or cobalt-containing alloys, that enable inward-type diffusion aluminide coatings having a substantially uniform coating thickness to be formed thereon. Substantially uniform coating thicknesses are achieved independent of applied slurry composition thickness or application method. The slurry coating composition of the invention comprises a Cr--Al alloy containing about 50 wt % to about 80 wt % Cr in the alloy, LiF in an amount greater than or equal to 0.3 wt % of the Cr--Al alloy, an organic binder, and a solvent.
    Type: Grant
    Filed: August 31, 1998
    Date of Patent: August 29, 2000
    Assignee: Sermatech International, Inc.
    Inventors: Thomas Kircher, Bruce G. McMordie, Srinivasan Shankar
  • Patent number: 4837389
    Abstract: A dimensional composition, a dimensionally restored alloy structure and a method of dimensionally restoring gas turbine and the like components that will be subsequently coated which includes low-pressure plasma spraying onto a damaged vane or other components, an alloy composition consisting essentially by weight of 1 to 4% aluminum, 0 to 1.5% hafnium and 0 to 20% nickel in the base composition of the cobalt alloy component, grinding to final dimension and diffusion coating. Tantalum is substituted for columbium where the base composition of the alloy contains columbium.
    Type: Grant
    Filed: June 4, 1984
    Date of Patent: June 6, 1989
    Assignee: Turbine Components Corporation
    Inventors: Srinivasan Shankar, George W. Goward
  • Patent number: 4764225
    Abstract: A nickel- or cobalt-based alloy of the type containing, by weight, 5 to 40% chromium, up to about 10% aluminum, up to about 10% titanium, up to about 30%, in combination, of elements from the group tantalum, tungsten, molybdenum, columbium, rhenium, or vanadium, up to about 2% silicon, up to about 5% hafnium, and up to about 5% reactive elements such as lanthanum, yttrium or other rare earths. Manganese is present in an amount from 0.1 to 12%, preferably 0.5 to 4%. Silicon in amounts from 1.0 to 2.0 by weight, or hafnium in amounts from 0.1 to 5.0% by weight may also be used. Alloys in accordance with this invention are particularly suitable for casting by the single crystal technique; however, the alloys can also be used in the production of polycrystalline components such as directionally solidified, conventionally solidified (equiaxed), wrought, or dispersion strengthened materials. In the latter case, grain boundary modifiers such as carbon, boron, zirconium and hafnium are utilized.
    Type: Grant
    Filed: May 13, 1980
    Date of Patent: August 16, 1988
    Assignee: Howmet Corporation
    Inventors: Srinivasan Shankar, Louis E. Dardi
  • Patent number: 4615864
    Abstract: Coatings for iron-, nickel- and cobalt-base superalloys. The coatings are applied in order to provide good oxidation and/or sulfidation and thermal fatigue resistance for the substrates to which the coatings are applied. The coatings consist essentially of, by weight, 10 to 50% chromium, 3 to 15% aluminum, 0.1 to 10% manganese, up to 8% tantalum, up to 5% tungsten, up to 5% reactive metal from the group consisting of lanthanum, yttrium and other rare earth elements, up to 5 percent of rare earth and/or refractory metal oxide particles, up to 12% silicon, up to 10% hafnium, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated.
    Type: Grant
    Filed: April 23, 1982
    Date of Patent: October 7, 1986
    Assignee: Howmet Turbine Components Corporation
    Inventors: Louis E. Dardi, Srinivasan Shankar
  • Patent number: 4526814
    Abstract: Methods are provided for forming protective diffusion layers on nickel, cobalt and iron base alloy parts comprising the formation of a diffusion layer of platinum, chromium and aluminum on said surfaces either by deposition of platinum and gas phase chromizing followed by aluminizing or by gas phase chromizing and deposition of platinum followed by aluminizing, or by gas phase chromizing followed by aluminizing and deposition of platinum, said gas phase chromizing performed out of contact with a source of gaseous chromizing species at elevated temperature, said aluminizing performed either out of contact or in contact with a powder mixture at elevated temperature.
    Type: Grant
    Filed: November 19, 1982
    Date of Patent: July 2, 1985
    Assignee: Turbine Components Corporation
    Inventors: Srinivasan Shankar, G. William Goward
  • Patent number: 4501776
    Abstract: Methods are provided for forming protective diffusion layers on nickel, cobalt and iron base alloy parts comprising the steps of depositing a coating of a platinum group metal on the surface of the part to be protected and forming a diffusion layer of platinum and aluminum on said surfaces by gas phase aluminizing said surfaces out of contact with a source of gaseous aluminizing species at elevated temperature.
    Type: Grant
    Filed: November 1, 1982
    Date of Patent: February 26, 1985
    Assignee: Turbine Components Corporation
    Inventor: Srinivasan Shankar
  • Patent number: 4447503
    Abstract: Coatings for iron-, nickel- and cobalt-base superalloys and the resulting coated components having good high temperature oxidation resistance. The coatings consist essentially of, by weight, 5% to 50% chromium, 3% to 30% aluminum, 0.01% to 15% tantalum, up to 10% manganese, up to 5% tungsten, up to 12% silicon, up to 10% hafnium, up to 5% reactive metal from the group consisting of lanthanum, yttrium, and other rare earth elements, up to 5% of rare earth and/or refractory metal oxide particles, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated.
    Type: Grant
    Filed: March 31, 1981
    Date of Patent: May 8, 1984
    Assignee: Howmet Turbine Components Corporation
    Inventors: Louis E. Dardi, Srinivasan Shankar
  • Patent number: 4339509
    Abstract: Coatings for iron-, nickel- and cobalt-base superalloys. The coatings are applied in order to provide good oxidation and/or sulfidation and thermal fatigue resistance for the substrates to which the coatings are applied. The coatings consist essentially of, by weight, 10 to 50% chromium, 3 to 15% aluminum, 0.1 to 10% manganese, up to 8% tantalum, up to 5% tungsten, up to 5% reactive metal from the group consisting of lanthanum, yttrium and other rare earth elements, up to 5 percent of rare earth and/or refractory metal oxide particles, up to 12% silicon, up to 10% hafnium, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated.
    Type: Grant
    Filed: May 1, 1980
    Date of Patent: July 13, 1982
    Assignee: Howmet Turbine Components Corporation
    Inventors: Louis E. Dardi, Srinivasan Shankar
  • Patent number: 4313760
    Abstract: Coatings for iron-, nickel- and cobalt-base superalloys. The coatings are applied in order to provide good oxidation/sulfidation and thermal fatigue resistance for the substrates to which the coatings are applied. The coatings consist essentially of, by weight, 10 to 50% chromium, 3 to 15% aluminum, 1.0 to 15% metal mixture from the group consisting of tantalum, tungsten, manganese and combinations thereof, up to 5% reactive metal from the group consisting of lanthanum, yttrium and other rare earth elements, up to 5 percent of rare earth and/or refractory metal oxide particles, and the balance selected from the group consisting of nickel, cobalt and iron, and combinations thereof. Additions of titanium up to 5% and noble metals up to 15% are also contemplated. Tantalum makes up at least 20% of the metal mixture or 0.5% of the total coating weight, whichever is greater. Tungsten, manganese, or a combination thereof, make up at least 0.5% of the total coating.
    Type: Grant
    Filed: August 16, 1979
    Date of Patent: February 2, 1982
    Assignee: Howmet Turbine Components Corporation
    Inventors: Louis E. Dardi, Srinivasan Shankar