Patents Assigned to D & M Technologies
  • Coated valve metal article formed by spark anodizing
    Patent number: 3956080
    Abstract: Metals and alloys which have the property of electrolytic rectification are coated by immersion in an aqueous bath comprising an alkali metal hydroxide, an alkali metal silicate and a catalyst and application of a sufficiently high voltage to obtain spark discharge at the surface to be coated thereby to provide a durable coating on the surface.
    Type: Grant
    Filed: August 22, 1974
    Date of Patent: May 11, 1976
    Assignee: D & M Technologies
    Inventors: Rudolf J. Hradcovsky, S. Heagan Bayles, Jr.