A method for making bearings for engines and gas turbines is the subject of
British patent application 2 243 841 filed by Motoren und Turbinen Union of
Munich. Its purpose is to coat a metal or ceramic base material with a dense
and perfectly formed skin of graphite. Where the bearing must also function
as a seal, the graphite particles take the form of hairs, which stand proud
of the surface of the base material like the bristles of a brush. The trick
is to coat the bearing under zero gravity.
In a zero-gravity laboratory in space, graphite particles or whiskers are
heated to sintering temperature to form a hot cloud. The particles are then
allowed to drift onto the metallic base material. Alternatively they can be
driven onto its surface by giving the particles and the surface opposite
electrical charges.
