Plasma spray systems and methods of uniformly coating rotary cylindrical targets

A plasma spray system, comprising:

• a vacuum chamber;
• one or more target assemblies including one or more target drive assemblies configured to move one or more cylindrical targets rotationally, laterally, longitudinally or any combination thereof;
• one or more power supplies;
• one or more plasma gas assemblies;
• one or more plasma spray devices operably adjoined to the one or more power supplies and the one or more plasma gas assemblies, wherein the plasma spray devices are oriented to direct a plasma stream toward a deposition zone on the cylindrical target;
• one or more particle control assemblies including one or more particle control conduits oriented to direct gas flows across the plasma streams between the plasma spray devices and the cylindrical targets to divert smaller plasma-sprayed particles and other small particles beyond the cylindrical targets;
• a vacuum system operably adjoined to the vacuum chamber;
• and
• one or more coating feeder apparatuses operably adjoined to one or more plasma spray devices for providing a coating material to the plasma streams for deposition on the cylindrical targets.

A plasma spray system, comprising:

• a vacuum chamber;
• one or more target assemblies positioned within the vacuum chamber, the target assemblies having one or more target drive assemblies configured to move one or more cylindrical targets rotationally, laterally, longitudinally or any combination thereof;
• one or more power supplies;
• one or more plasma gas assemblies;
• one or more plasma spray devices operably adjoined to the one or more power supplies and the one or more plasma gas assemblies, wherein the plasma spray devices are oriented to direct one or more plasma streams toward one or more deposition zones on the cylindrical targets;
• one or more coating feeder apparatuses operably adjoined to one or more plasma spray devices for providing a coating material to the plasma streams for deposition on the cylindrical targets;
• one or more preclean gas assemblies including one or more preclean gas conduits operably coupled to one or more gas storage units and oriented to direct gas flows or systematic blasts onto the deposition zones of the cylindrical targets before the deposition zones enter the plasma stream;
• and
• a vacuum system operably adjoined to the vacuum chamber.

A vacuum system comprising:

• a vacuum duct operably adjoined to the vacuum chamber, including:
• a blower system coupled to the vacuum duct for generating a vacuum flow;
• a chamber outlet having a reversibly constricting chamber outlet end;
• a venturi tube section positioned between the vacuum chamber and the blower system;
• and
• a gas detector positioned proximate to the chamber outlet for monitoring the backstreaming of atmospheric gases.

A method of uniformly coating a cylindrical target comprising:

• a. mounting a cylindrical target to a target assembly;
• b. moving the cylindrical target at a constant or variable rate rotationally, laterally, longitudinally or any combination thereof;
• c. activating one or more plasma spray devices to generate one or more plasma streams for plasma spraying particles of a coating material toward a deposition zone on the cylindrical target;
• and
• d. plasma spraying particles of coating material on the cylindrical target until a uniform coating of desired thickness is achieved.

A method of coating a cylindrical target comprising:

• a. mounting a cylindrical target to a target assembly;
• b. moving the cylindrical target at a constant or variable rate rotationally, laterally, longitudinally or any combination thereof;
• c. activating one or more plasma spray devices to generate one or more plasma streams for plasma spraying particles of a coating material toward a deposition zone on the cylindrical target;
• d. directing gas flow across the plasma streams between the plasma spray devices and the cylindrical target to divert smaller plasma-sprayed particles and other small particles beyond the cylindrical target;
• and
• e. plasma spraying particles of coating material on the cylindrical target until a uniform coating of predetermined thickness is attained.

A method of coating a cylindrical target comprising:

• a. mounting a cylindrical target to a target assembly;
• b. moving the cylindrical target at a variable or constant rate rotationally, laterally, longitudinally or any combination thereof;
• c. starting and stopping the motion of the cylindrical target at varying points;
• d. activating one or more plasma spray devices to generate one or more plasma streams for plasma spraying particles of a coating material toward a deposition zone on the cylindrical target;
• e. directing a gas flow or systematic blast of gas onto a surface location of the cylindrical target proximate to the deposition zone before entering the plasma streams to preclean the deposition zone;
• and
• f. plasma spraying particles of coating material on the cylindrical target until a uniform coating of predetermined thickness is attained.