| abstract |
An oriented graphite layer is formed on a metallic substrate by providing a coating of particulate carbon thereon, heating the coated substrate in a non-reactive atmosphere to a temperature of between 800 DEG and 1350 DEG C. for saturational diffusion of carbon into the substrate and cooling to a temperature below about 200 DEG C., thereby providing a precipitated oriented graphite film at the surface of the substrate. The substrate may be formed by covering a copper or copper alloy member with a continuous layer of nickel, cobalt, nickel alloy or cobalt alloy. In another embodiment, the substrate with an attached graphite coating is spirally bonded onto a copper tube for use in the field of condensation heat transfer. |