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

摘要

An apparatus for generating an arc plasma in a non-local thermal equilibrium and an apparatus for the deposition of a material upon a substrate comprising the above are disclosed.;Referring to the accompanying illustrative drawing, 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) 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 Hemholtz 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 substrate adjacent thereto.;The apparatus generates a non-local thermal equilibrium arc plasma at the relatively high pressure of at least 1 atmosphere.;The present invention provides advantages over the prior art.