US 4,536,640 A · High pressure, non-logical thermal equilibrium arc plasma generating apparatus for deposition of coatings upon substrates

Abstract

An apparatus for deposition of coatings upon substrates generates a non-local thermal equilibrium arc plasma at the relatively high pressure of at least approximately 1 atmosphere. A closed chamber (25) is defined by a cylindrical anode (11) and annular housings (21, 22) carrying transparent end plates (23, 24). A pencil-shaped cathode (12) is passed through one end plate (23 or 24) coaxially into chamber (25) so that its tapered end (20) is spatially proximate to an exit orifice (44) centrally located in anode (11). Gas ports (30, 31) permit the introduction of a preselected gaseous environment at the desired pressure into chamber (25). A low-current arc is struck between anode (11) and cathode (12) establishing the desired plasma. Two coils (33, 34) are coaxially placed radially outward of both ends of the chamber in a Helmholtz coil configuration to generate a uniform magnetic field in chamber (25) and induce rotation of the arc plasma. The coating material is introduced into the plasma as by a reservoir (40) in cathode (12) and its excited species ejected through exit orifice (44) in a plasma jet for deposition upon any substrate adjacent thereto.

Claims11

Dependent claims

An apparatus for depositing a material on a substrate from an arc plasma, said apparatus comprising:

a chamber within which a plasma arc may be struck and maintained;
a tubular first electrode having a first central axis, opposing ends and defining a wall of said chamber;
end plates closing said ends of said first electrode to define said chamber;
a housing for mounting said end plates on said first electrode including a port in communication with the interior of said chamber for passage of a preselected gas into said chamber;
a second electrode coaxial with said first electrode, said second electrode having a tip for supporting said arc, said second electrode extending into said chamber through one of said end plates;
magnet means for establishing a magnetic field proximate said tip for inducing rotation of said plasma around said central axis of said first electrode;
means for introducing into said plasma a material to be deposited on a substrate;
and
an orifice in said first electrode having a second central axis transverse to said first central axis and proximate said tip for passage out of said chamber of a tangential portion of said rotating plasma bearing said material to deposited to a substrate.

6 more elements

Dependencies are inferred from the claim text.

High pressure, non-logical thermal equilibrium arc plasma generating apparatus for deposition of coatings upon substrates

Life of this patent

High pressure, non-logical thermal equilibrium arc plasma generating apparatus for deposition of coatings upon substrates

Life of this patent

Abstract

Claims11