Patents by Inventor Charles K. Witham

Charles K. Witham 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: 6074453
    Abstract: A method of making hydrogen storage powder resistant to fracture in service involves forming a melt having the appropriate composition for the hydrogen storage material, such, for example, LaNi.sub.5 and other AB.sub.5 type materials and AB.sub.5+x materials, where x is from about -2.5 to about +2.5, including x=0, and the melt is gas atomized under conditions of melt temperature and atomizing gas pressure to form generally spherical powder particles. The hydrogen storage powder exhibits improved chemcial homogeneity as a result of rapid solidfication from the melt and small particle size that is more resistant to microcracking during hydrogen absorption/desorption cycling. A hydrogen storage component, such as an electrode for a battery or electrochemical fuel cell, made from the gas atomized hydrogen storage material is resistant to hydrogen degradation upon hydrogen absorption/desorption that occurs for example, during charging/discharging of a battery.
    Type: Grant
    Filed: October 28, 1997
    Date of Patent: June 13, 2000
    Assignees: Iowa State University Research Foundation, Inc., California Institute of Technology
    Inventors: Iver E. Anderson, Timothy W. Ellis, Vitalij K. Pecharsky, Jason Ting, Robert Terpstra, Robert C. Bowman, Charles K. Witham, Brent T. Fultz, Ratnakumar V. Bugga
  • Patent number: 5888665
    Abstract: An at least ternary metal alloy of the formula AB.sub.(Z-Y) X.sub.(Y) is disclosed. In this formula, A is selected from the rare earth elements, B is selected from the elements of Groups 8, 9, and 10 of the Periodic Table of the Elements, and X includes at least one of the following: antimony, arsenic, germanium, tin or bismuth. Z is greater than or equal to 4.8 and less than or equal to 6.0. Y is greater than 0 and less than 1. Ternary or higher-order substitutions to the base AB.sub.5 alloys that form strong kinetic interactions with the predominant metals in the base metal hydride are used to form metal alloys with high structural integrity after multiple cycles of hydrogen sorption.
    Type: Grant
    Filed: December 13, 1996
    Date of Patent: March 30, 1999
    Assignee: California Institute of Technology
    Inventors: Ratnakumar V. Bugga, Brent Fultz, Robert Bowman, Subra Rao Surampudi, Charles K. Witham, Adrian Hightower
  • Patent number: 5656388
    Abstract: An at least ternary metal alloy of the formula, AB.sub.(5-Y)X(.sub.y), is claimed. In this formula, A is selected from the rare earth elements, B is selected from the elements of groups 8, 9, and 10 of the periodic table of the elements, and X includes at least one of the following: antimony, arsenic, and bismuth. Ternary or higher-order substitutions, to the base AB.sub.5 alloys, that form strong kinetic interactions with the predominant metals in the base metal hydride are used to form metal alloys with high structural integrity after multiple cycles of hydrogen sorption.
    Type: Grant
    Filed: June 7, 1995
    Date of Patent: August 12, 1997
    Assignee: California Institute of Technology
    Inventors: Ratnakumar V. Bugga, Gerald Halpert, Brent Fultz, Charles K. Witham, Robert C. Bowman, Adrian Hightower