Patents by Inventor William S. Walston

William S. Walston 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: 6969558
    Abstract: A coated article is prepared by furnishing an nickel-base article substrate having a free sulfur content of more than 0 but less than about 1 part per million by weight. A protective layer is formed at a surface of the article substrate. The protective layer includes a platinum aluminide diffusion coating. The protective layer may be substantially yttrium-free, or have a controlled amount of yttrium. A ceramic layer may overlie the protective layer.
    Type: Grant
    Filed: November 18, 2003
    Date of Patent: November 29, 2005
    Assignee: General Electric Company
    Inventors: William S. Walston, Jon C. Schaeffer, Wendy H. Murphy
  • Patent number: 6797408
    Abstract: A coated article is prepared by furnishing an nickel-base article substrate having a free sulfur content of more than 0 but less than about 1 part per million by weight. A protective layer is formed at a surface of the article substrate. The protective layer includes a platinum aluminide diffusion coating. The protective layer may be substantially yttrium-free, or have a controlled amount of yttrium. A ceramic layer may overlie the protective layer.
    Type: Grant
    Filed: December 11, 2001
    Date of Patent: September 28, 2004
    Assignee: General Electric Company
    Inventors: William S. Walston, Jon C. Schaeffer, Wendy H. Murphy
  • Publication number: 20040123923
    Abstract: A coated article is prepared by furnishing an nickel-base article substrate having a free sulfur content of more than 0 but less than about 1 part per million by weight. A protective layer is formed at a surface of the article substrate. The protective layer includes a platinum aluminide diffusion coating. The protective layer may be substantially yttrium-free, or have a controlled amount of yttrium. A ceramic layer may overlie the protective layer.
    Type: Application
    Filed: November 18, 2003
    Publication date: July 1, 2004
    Inventors: William S. Walston, Jon C. Schaeffer, Wendy H. Murphy
  • Patent number: 6656533
    Abstract: A coated article is prepared by furnishing an nickel-base article substrate having a free sulfur content of more than 0 but less than about 1 part per million by weight. A protective layer is formed at a surface of the article substrate. The protective layer includes a platinum aluminide diffusion coating. The protective layer may be substantially yttrium-free, or have a controlled amount of yttrium. A ceramic layer may overlie the protective layer.
    Type: Grant
    Filed: December 10, 2001
    Date of Patent: December 2, 2003
    Inventors: William S. Walston, Jon C. Schaeffer, Wendy H. Murphy
  • Patent number: 6582772
    Abstract: An article such as a gas turbine blade or vane has a superalloy substrate, and a coating system deposited on the substrate. The coating system includes a protective layer overlying the substrate, and, optionally, a ceramic thermal barrier coating layer overlying the bond coat. The protective layer has an uppermost layer with a composition including platinum, aluminum, and, in atom percent, from about 0.14 to about 2.8 percent hafnium and from about 2.7 to about 7.0 percent silicon, with the atomic ratio of silicon:hafnium being from about 1.7:1 to about 5.6:1.
    Type: Grant
    Filed: September 30, 2002
    Date of Patent: June 24, 2003
    Assignee: General Electric Company
    Inventors: Joseph D. Rigney, Ramgopal Darolia, William S. Walston
  • Patent number: 6551423
    Abstract: A method for preparing a coated nickel-base superalloy article reduces the sulfur content of the surface region of the metallic coating layers to low levels, thereby improving the adhesion of the coating layers to the article. The method includes depositing a first layer of platinum overlying the surface of a substrate, depositing a second layer of aluminum over the platinum, and final desulfurizing the article by heating the article to elevated temperature, preferably in hydrogen, and removing a small amount of material from the surface that was exposed during the step of heating. A ceramic layer may be deposited over the desulfurized article. The article may also be similarly desulfurized at other points in the fabrication procedure.
    Type: Grant
    Filed: September 8, 1998
    Date of Patent: April 22, 2003
    Assignee: General Electric Co.
    Inventors: Irene T. Spitsberg, William S. Walston, Jon C. Schaeffer
  • Publication number: 20030044536
    Abstract: An article such as a gas turbine blade or vane has a superalloy substrate, and a coating system deposited on the substrate. The coating system includes a protective layer overlying the substrate, and, optionally, a ceramic thermal barrier coating layer overlying the bond coat. The protective layer has an uppermost layer with a composition including platinum, aluminum, and, in atom percent, from about 0.14 to about 2.8 percent hafnium and from about 2.7 to about 7.0 percent silicon, with the atomic ratio of silicon:hafnium being from about 1.7:1 to about 5.6:1.
    Type: Application
    Filed: September 30, 2002
    Publication date: March 6, 2003
    Inventors: Joseph D. Rigney, Ramgopal Darolia, William S. Walston
  • Patent number: 6514629
    Abstract: An article such as a gas turbine blade or vane has a superalloy substrate, and a coating system deposited on the substrate. The coating system includes a protective layer overlying the substrate, and, optionally, a ceramic thermal barrier coating layer overlying the bond coat. The protective layer has an uppermost layer with a composition including platinum, aluminum, and, in atom percent, from about 0.14 to about 2.8 percent hafnium and from about 2.7 to about 7.0 percent silicon, with the atomic ratio of silicon:hafnium being from about 1.7:1 to about 5.6:1.
    Type: Grant
    Filed: December 15, 1998
    Date of Patent: February 4, 2003
    Assignee: General Electric Company
    Inventors: Joseph D. Rigney, Ramgopal Darolia, William S. Walston
  • Patent number: 6447932
    Abstract: A coating system and method for forming the coating system on an article designed for use in a hostile environment, such as the superalloy turbine, combustor and augmentor components of a gas turbine engine. The method employs a nitrided zone in the surface of the superalloy substrate to inhibit the formation of deleterious topologically-close packed (TCP) phases in the substrate when protected by an aluminum-rich coating and optionally a thermal insulating ceramic layer. Superalloys of particular interest are those containing significant levels of TCP phase-forming elements, such as tungsten, rhenium, tantalum, molybdenum and chromium.
    Type: Grant
    Filed: March 29, 2000
    Date of Patent: September 10, 2002
    Assignee: General Electric Company
    Inventors: Kevin S. O'Hara, William S. Walston, Jon C. Schaeffer
  • Patent number: 6444057
    Abstract: An article is formed of a single crystal having a composition, in weight percent, of a modifying element in an amount of from about 0.2 to about 2.0 percent by weight hafnium, from about 0.1 to about 0.5 percent by weight zirconium, or combinations thereof, and a base alloy composition of from about 4 to about 20 percent cobalt, from about 1 to about 10 percent chromium, from about 5 to about 7 percent aluminum, from 0 to about 2 percent molybdenum, from about 3 to about 8 percent tungsten, from about 4 to about 12 percent tantalum, from 0 to about 2 percent titanium, from 0 to about 8 percent rhenium, from 0 to about 6 percent ruthenium, from 0 to about 1 percent niobium, from 0 to about 0.1 percent carbon, from 0 to about 0.01 percent boron, from 0 to about 0.1 percent yttrium, and balance nickel and incidental impurities.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: September 3, 2002
    Assignee: General Electric Company
    Inventors: Ramgopal Darolia, Jeffrey A. Pfaendtner, William S. Walston
  • Publication number: 20020055004
    Abstract: A coated article is prepared by furnishing an nickel-base article substrate having a free sulfur content of more than 0 but less than about 1 part per million by weight. A protective layer is formed at a surface of the article substrate. The protective layer includes a platinum aluminide diffusion coating. The protective layer may be substantially yttrium-free, or have a controlled amount of yttrium. A ceramic layer may overlie the protective layer.
    Type: Application
    Filed: December 11, 2001
    Publication date: May 9, 2002
    Inventors: William S. Walston, Jon C. Schaeffer, Wendy H. Murphy
  • Publication number: 20020048683
    Abstract: A coated article is prepared by furnishing an nickel-base article substrate having a free sulfur content of more than 0 but less than about 1 part per million by weight. A protective layer is formed at a surface of the article substrate. The protective layer includes a platinum aluminide diffusion coating. The protective layer may be substantially yttrium-free, or have a controlled amount of yttrium. A ceramic layer may overlie the protective layer.
    Type: Application
    Filed: December 10, 2001
    Publication date: April 25, 2002
    Inventors: William S. Walston, Jon C. Schaeffer, Wendy H. Murphy
  • Patent number: 6333121
    Abstract: A coated article is prepared by furnishing an nickel-base article substrate having a free sulfur content of more than 0 but less than about 1 part per million by weight. A protective layer is formed at a surface of the article substrate. The protective layer includes a platinum aluminide diffusion coating. The protective layer may be substantially yttrium-free, or have a controlled amount of yttrium. A ceramic layer may overlie the protective layer.
    Type: Grant
    Filed: June 9, 1999
    Date of Patent: December 25, 2001
    Assignee: General Electric Company
    Inventors: William S. Walston, Jon C. Schaeffer, Wendy H. Murphy
  • Patent number: 6190471
    Abstract: A superalloy article has a protective layer thereon, either in the form of an environmental coating or a the bond coat for a thermal barrier coating system. The protective layer has a high content of hafnium and/or zirconium to improve the adherence and properties of the protective layer. To introduce the hafnium and/or zirconium into the protective layer, the nickel-base alloy substrate, to which the protective layer is applied, is prepared with an initially elevated content of the hafnium and/or zirconium. A conventional bond coat is applied to the substrate. In an interdiffusion treatment performed during coating and/or subsequently, hafnium and/or zirconium diffuses from the substrate into the bond coat.
    Type: Grant
    Filed: May 26, 1999
    Date of Patent: February 20, 2001
    Assignee: General Electric Company
    Inventors: Ramgopal Darolia, William S. Walston
  • Patent number: 6153313
    Abstract: A coating system (20) for articles used in hostile thermal environments, such as turbine, combustor and augmentor components (10) of a gas turbine engine. The coating system (20) of this invention employs a NiAl-based intermetallic coating (24) containing 30 to 60 atomic percent aluminum so as to be predominantly of the .beta.-NiAl phase, but also contains alloying additions intended to increase the creep strength of the coating (24), and optionally contains alloying additions to getter impurities, increase fracture resistance, and promote oxidation resistance. For this purpose, the coating (24) preferably includes additions of chromium, titanium, tantalum, silicon, hafnium and/or gallium, and optionally contains additions of calcium, zirconium, yttrium, and/or iron.
    Type: Grant
    Filed: October 6, 1998
    Date of Patent: November 28, 2000
    Assignee: General Electric Company
    Inventors: Joseph D. Rigney, Ramgopal Darolia, William S. Walston, Reed R. Corderman
  • Patent number: 5935353
    Abstract: A coated Ni base superalloy article is provided with improved microstuctural stability under a coating at least partially diffused into an article surface portion, by avoiding the formation, after exposure to elevated temperatures, of a constituent called SRZ which can affect detrimentally mechanical properties of the article. Such avoidance can result from neutralizing stress in the article surface portion prior to coating, for example by physically removing the stressed portion or by recrystallizing the stressed portion to a fine grained structure which subsequently can be consumed by diffusing elements in a coating method. Also, such avoidance can result from maintaining a Re segregation factor, Re.DELTA., between dendrite cores and interdendritic regions of the alloy cast structure at no greater than about 40%.
    Type: Grant
    Filed: December 8, 1997
    Date of Patent: August 10, 1999
    Assignee: General Electric Company
    Inventors: Wendy H. Murphy, William S. Walston
  • Patent number: 5695821
    Abstract: A coated Ni base superalloy article is provided with improved microstructural stability under a coating at least partially diffused into an article surface portion, by avoiding the formation, after exposure to elevated temperatures, of a constituent called SRZ which can affect detrimentally mechanical properties of the article. Such avoidance can result from neutralizing stress in the article surface portion prior to coating, for example by physically removing the stressed portion or by recrystallizing the stressed portion to a fine grained structure which subsequently can be consumed by diffusing elements in a coating method. Also, such avoidance can result from maintaining a Re segregation factor, Re.DELTA., between dendrite cores and interdendritic regions of the alloy cast structure at no greater than about 40%.
    Type: Grant
    Filed: September 14, 1995
    Date of Patent: December 9, 1997
    Assignee: General Electric Company
    Inventors: Wendy H. Murphy, William S. Walston
  • Patent number: 5516380
    Abstract: A NiAl intermetallic alloy and article is provided with improved high temperature strength, particularly stress rupture strength, through the generation of a multiphase microstructure comprising a beta matrix and at least one precipitate phase. The strength properties and microstructure are the result of alloying with at least two elements selected from Ga, Hf, and optionally Ti, Zr, Ta, Nb, and V, in defined ranges. Preferred are at least two of the elements Ga, Hf, and Ti, and specifically preferred are all three. A specifically preferred form of the invention, in atomic percent, is about 45-59% Ni, about 0.02-0.5% Ga, about 0.2 to less than 1% Hf, about 0.1-10% Ti, with the balance A1 and incidental impurities.
    Type: Grant
    Filed: October 14, 1994
    Date of Patent: May 14, 1996
    Assignee: General Electric Company
    Inventors: Ramgopal Darolia, James R. Dobbs, Robert D. Field, Edward H. Goldman, David F. Lahrman, William S. Walston
  • Patent number: 5482789
    Abstract: The present invention provides a nickel base superalloy having an improved combination of stress rupture life and microstructural stability with respect to the formation of TCP phases. A unique feature is the specific combination of the content of elements consisting of Al, Ti and W in a second range defined by their sum in a nickel base superalloy having high contents of rhenium, in excess of 1.3 atomic percent (about 4.0 weight percent) to lower the propensity for TCP phase formation and thus render the alloy more stable at high temperatures. The interaction of Ru with the remaining elements to modify the refractory element phase partitioning provides unique capabilities, causing elements to partition to the gamma phase or the gamma prime phase in a reverse direction than normally experienced in Ni-base superalloys. These Ni-base superalloys are termed Ru-containing Reverse Partitioning Ni-base Superalloys.
    Type: Grant
    Filed: January 3, 1994
    Date of Patent: January 9, 1996
    Assignee: General Electric Company
    Inventors: Kevin S. O'Hara, William S. Walston, Earl W. Ross, Ramgopal Darolia
  • Patent number: 5455120
    Abstract: A nickel base superalloy capable of being made into a single crystal article is provided with high temperature strength and improved stability by limiting the presence of an undesirable SRZ constituent. Significant to the control of formation of such undesirable constituents is the control of the amount of Re in the alloy in combination with elements such as Al, Cr, Ta, Mo, Co and W. A solution heat treatment is provided for additional control.
    Type: Grant
    Filed: July 29, 1993
    Date of Patent: October 3, 1995
    Assignee: General Electric Company
    Inventors: William S. Walston, Earl W. Ross, Tresa M. Pollock, Kevin S. O'Hara, Wendy H. Murphy