Patents by Inventor Randal S. Hay

Randal S. Hay 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).

  • Oxidation-resistant fiber coatings and related methods
    Patent number: 11780780
    Abstract: A method of manufacturing a coated reinforcing fiber for use in Ceramic Matrix Composites, the method comprising pre-oxidizing a plurality of silicon-based fibers selected from the group consisting of silicon carbide (SiC) fibers, silicon nitride (Si3N4) fibers, SiCO fibers, SiCN fibers, SiCNO fibers, and SiBCN fibers at between 700 to 1300 degrees Celsius in an oxidizing atmosphere to form a silica surface layer on the plurality of silicon-based fibers, forming a plurality of pre-oxidized fibers; applying a rare earth orthophosphate (REPO4) coating to the plurality of pre-oxidized fibers; and heating the plurality of REPO4 coated pre-oxidized fibers at about 1000-1500 degrees Celsius in an inert atmosphere to react the REPO4 with the silica surface layer to form a rare earth silicate or disilicate. The pre-oxidizing step may be 0.5 hours to about 100 hours. The heating step may be about 5 minutes to about 100 hours.
    Type: Grant
    Filed: March 29, 2021
    Date of Patent: October 10, 2023
    Assignee: United States of America as represented by the Secretary of the Air Force
    Inventors: Emmanuel E Boakye, Michael K Cinibulk, Randal S Hay, Pavel Mogilevsky, Triplicane A Parthasarathy, Kristin A Keller
  • OXIDATION-RESISTANT FIBER COATINGS AND RELATED METHODS
    Publication number: 20210340067
    Abstract: A method of manufacturing a coated reinforcing fiber for use in Ceramic Matrix Composites, the method comprising pre-oxidizing a plurality of silicon-based fibers selected from the group consisting of silicon carbide (SiC) fibers, silicon nitride (Si3N4) fibers, SiCO fibers, SiCN fibers, SiCNO fibers, and SiBCN fibers at between 700 to 1300 degrees Celsius in an oxidizing atmosphere to form a silica surface layer on the plurality of silicon-based fibers, forming a plurality of pre-oxidized fibers; applying a rare earth orthophosphate (REPO4) coating to the plurality of pre-oxidized fibers; and heating the plurality of REPO4 coated pre-oxidized fibers at about 1000-1500 degrees Celsius in an inert atmosphere to react the REPO4 with the silica surface layer to form a rare earth silicate or disilicate. The pre-oxidizing step may be 0.5 hours to about 100 hours. The heating step may be about 5 minutes to about 100 hours.
    Type: Application
    Filed: March 29, 2021
    Publication date: November 4, 2021
    Inventors: Emmanuel E. Boakye, Michael K. Cinibulk, Randal S. Hay, Pavel Mogilevsky, Triplicane A. Parthasarathy, Kristin A. Keller