Patents Examined by A. E. Brookes
  • Patent number: 4554218
    Abstract: A precision molded article, such as a die cavity, is made by combining granules of a first metal or alloy and a second metal or alloy, the second metal or alloy having a homogeneous appearance at some temperature below its melting point, and a higher Rockwell Hardness than the first metal or alloy, mixing the granules with a heat fugitive organic binder, molding the granule-binder mixture into a green molded preform, thermally degrading and removing essentially all the binder to form a skeletal preform, and infiltrating the preform with a third metal or alloy which will wet the second metal or alloy and has a lower Rockwell Hardness than the second metal or alloy, thereby forming a molded article having granules of first metal or alloy the majority of which are fully enveloped within a single skeleton of the second metal or alloy, the skeleton of second metal or alloy being surrounded by layers or matrices of softer metals.
    Type: Grant
    Filed: May 18, 1984
    Date of Patent: November 19, 1985
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Richard N. Gardner, Kenneth R. Dillon