Patents by Inventor Hun C. Yeh

Hun C. Yeh 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).

  • Method for forming a high strength silicon nitride
    Patent number: 4994219
    Abstract: A method for forming a improved silicon nitride material characterized by high mechanical strength at high temperatures comprising a combination of approximately 0.5-6.0% by weight of strontium oxide, 2.0-12.0% by weight of yttrium oxide and the balance silicon nitride. The improved material is densified by either an encapsulated hot isostatic pressing method or an unencapsulated sinter/HIP method and can be utilized to form near net shape articles.
    Type: Grant
    Filed: June 19, 1989
    Date of Patent: February 19, 1991
    Assignee: Allied-Signal Inc.
    Inventor: Hun C. Yeh
  • High strength silicon nitride
    Patent number: 4870036
    Abstract: An improved silicon nitride material characterized by high mechanical strength at high temperatures comprising a combination of approximately 0.5-6.0% by weight of strontium oxide, 2.0-12% by weight of yttrium oxide and the balance silicon nitride. The improved material is densified by either an encapsulated hot isostatic pressing method or an encapsulated sinter/HIP method and can be utilized to form near net shape articles.
    Type: Grant
    Filed: March 8, 1988
    Date of Patent: September 26, 1989
    Assignee: Allied-Signal Inc.
    Inventor: Hun C. Yeh