Abstract: An electrode assembly comprises a coil of electrode material surrounded by a shield having one or more outlets and a supply of shielding gas directed along an axis X-X of said coil before exiting from said shield.

Abstract: A method and system for coating the internal surfaces of a workpiece is presented. A bias voltage is connected to a workpiece, which functions as a cathode. A gas source and a vacuum source are coupled to each opening through a flow control system. The flow control system is capable of a first mode which enables a first opening to function as a gas inlet and a second opening to function as a vacuum exhaust. The flow control system also has a second mode which enables a first opening to function as a vacuum exhaust and a second opening to function as a gas inlet. The cycling may also be used to coat internal surfaces of a workpiece with a single opening. Cycling the flow control system between the first mode and second mode is performed until a uniform coating along the internal surfaces of the workpiece is achieved.

Abstract: A method and system for coating the internal surfaces of a localized area or section of a workpiece is presented. Conductive structures are inserted into one or more openings of a workpiece to define the section to be coated. In some embodiments, a bias voltage is connected to a workpiece section, which functions as a cathode. A gas source and vacuum source are coupled to each conductive structure through a flow control system. The flow control system enables a first opening to function as a gas inlet and a second opening to function as a vacuum exhaust. Only the section encompassed by the conductive structures is coated. When the coating process is completed, a means for varying the conductive structures along the length is utilized to move onto the next section to be coated.

Abstract: The coating of internal surfaces of a workpiece is achieved by connecting a bias voltage such that the workpiece functions as a cathode and by connecting an anode at each opening of the workpiece. A source gas is introduced at an entrance opening, while a vacuum source is connected at an exit opening. Pressure within the workpiece is monitored and the resulting pressure information is used for maintaining a condition that exhibits the hollow cathode effect. Optionally, a pre-cleaning may be provided by introducing a hydrocarbon mixture and applying a negative bias to the workpiece, so as to sputter contaminants from the workpiece using argon gas. Argon gas may also be introduced during the coating processing to re-sputter the coating, thereby improving uniformity along the length of the workpiece. The coating may be a diamond-like carbon material having properties which are determined by controlling ion bombardment energy.

Abstract: An apparatus for coating surfaces of a workpiece is configured to establish a pressure gradient within internal passageways through the workpiece, so that the coating within the internal passageways exhibits intended characteristics, such as those relating to smoothness or hardness. The coating apparatus may include any or all of a number of cooperative systems, including a plasma generation system, a manipulable workpiece support system, an ionization excitation system configured to increase ionization within or around the workpiece, a biasing system for applying a selected voltage pattern to the workpiece, and a two-chamber system that enables the plasma generation to take place at a first selected pressure and the deposition to occur at a second selected pressure.