Abstract: A system (100), apparatus (110), and method (900) for creating a particle stream (70) that is deflected with a secondary gas (518) such as air before coming into contact with the treated substrate surface (80). The system (100) can be implemented as an improvement to a prior art PTWA (plasma transferred wire arc) thermal spraying apparatus (50) by using a non-symmetrical passageway configuration (549). Such a configuration can be an attribute of a nozzle (220) or a secondary gas director (576) such as an air baffle (578).

Abstract: A system (100), apparatus (110), and method (900) for monitored thermal spraying. One or more sensors (610) are used to capture one or more types of measurements (650) to monitor the thermal spraying process. A processor (710) can analyze a waveform (750) of measurements (650), such as electrical measurements (652). The processor (710) can then initiate a response (770) such as a warning (772) or an automatic adjustment (790) that is triggered by an identified operating condition (800).

Abstract: A system (100), apparatus (110), and method (900) for monitored thermal spraying. One or more sensors (610) are used to capture one or more types of measurements (650) to monitor the thermal spraying process. A processor (710) can analyze a waveform (750) of measurements (650), such as electrical measurements (652). The processor (710) can then initiate a response (770) such as a warning (772) or an automatic adjustment (790) that is triggered by an identified operating condition (800).

Abstract: A coating system that applies a coating of particles to a surface of an article. The coating system comprises a hybrid plasma torch which may include a cathode, a first plasma gas chamber, a first mixing chamber, a plasma generator for generating an arc column of plasma, a second mixing chamber for mixing a main gas, an at least partially ionized first plasma gas and a second gas that was mixed in the first mixing chamber, wherein the second mixing chamber is dimensioned to receive a plurality of powder particles suspended in a carrier gas, and an accelerator assembly for accelerating the mixture of the main gas, the at least partially ionized first plasma gas, the second plasma gas and the powder particles into a high-velocity stream and for directing the high-velocity stream against the surface of the article. A method of applying the coating of particles is also provided.

Abstract: A method of thermally depositing metal onto a target surface using a plasma transferred wire arc thermal spray apparatus, wherein the method includes the steps of offsetting the central axis of a consumable wire with respect to an axial centerline of a constricting orifice; and establishing and operating a plasma transferred wire arc between a cathode and a free end of the consumable wire; and melting and atomizing a continually fed free end of the consumable wire into molten metal particles and projecting the particles onto said target surface.

Abstract: A method of thermally depositing metal onto a target surface using a plasma transferred wire arc thermal spray apparatus, wherein the method includes the steps of offsetting the central axis of a consumable wire with respect to an axial centerline of a constricting orifice; and establishing and operating a plasma transferred wire arc between a cathode and a free end of the consumable wire; and melting and atomizing a continually fed free end of the consumable wire into molten metal particles and projecting the particles onto said target surface.

Abstract: A feeder apparatus supplies a powder feedstock to a high or low pressure processing operation. The apparatus includes a metering plate defining an annular channel having a channel width. A measuring mechanism dispenses a measured volume of the feedstock into the annular channel. The measuring mechanism includes a pay-out device defining an outlet significantly smaller than the channel width. The measuring mechanism further includes a maximum fill level defining a maximum pressure head in the feedstock less than a retaining pressure defined by the internal friction of the feedstock. The restraining pressure prevents the feedstock from spreading outwardly in the annular channel and contacting sidewalls of the annular channel under the pressure head of the feedstock. The apparatus further includes a pick-up device for removing the feedstock from the annular channel. The pick-up device includes an inlet having a rectangular shape extending across the annular channel.

Abstract: A plasma spray apparatus for applying a coating to an article, wherein the apparatus includes a cup shaped plasma nozzle and a main gas nozzle coaxially surrounding the exterior of the plasma nozzle forming a passage between the main gas nozzle and the plasma nozzle through which the main gas containing powder particles is caused to coaxially flow, and a converging/diverging nozzle positioned at the exit of the plasma nozzle and main gas nozzle, having an entry chamber into which the plasma gas and the main gas with powder particles entrained therein flow and combine to establish a gas mixture, the gas mixture accelerating through the extended bore of the converging/diverging nozzle to a sonic or supersonic velocity so that upon impact onto the surface of the article a cohesively bonded coating will form and build-up.

Abstract: A feeder apparatus supplies a powder feedstock to a high or low pressure processing operation. The apparatus includes a metering plate defining an annular channel having a channel width. A measuring mechanism dispenses a measured volume of the feedstock into the annular channel. The measuring mechanism includes a pay-out device defining an outlet significantly smaller than the channel width. The measuring mechanism further includes a maximum fill level defining a maximum pressure head in the feedstock less than a retaining pressure defined by the internal friction of the feedstock. The restraining pressure prevents the feedstock from spreading outwardly in the annular channel and contacting sidewalls of the annular channel under the pressure head of the feedstock. The apparatus further includes a pick-up device for removing the feedstock from the annular channel. The pick-up device includes an inlet having a rectangular shape extending across the annular channel.

Abstract: A method of operation of a plasma torch and the plasma apparatus to produce a hot gas jet stream directed towards a workpiece to be coated by first injecting a cold high pressure carrier gas containing a powder material into a cold main high pressure gas flow and then directing this combined high pressure gas flow coaxially around a plasma exiting from an operating plasma generator and converging directly into the hot plasma effluent, thereby mixing with the hot plasma effluent to form a gas stream with a net temperature based on the enthalpy of the plasma stream and the temperature and volume of the cold high pressure converging gas, establishing a net temperature of the gas stream at a temperature such that the powdered material will not melt or soften, and projecting the powder particles at high velocity onto a workpiece surface.

Abstract: A method of operation of a plasma torch and the plasma apparatus to produce a hot gas jet stream directed towards a workpiece to be coated by first injecting a cold high pressure carrier gas containing a powder material into a cold main high pressure gas flow and then directing this combined high pressure gas flow coaxially around a plasma exiting from an operating plasma generator and converging directly into the hot plasma effluent, thereby mixing with the hot plasma effluent to form a gas stream with a net temperature based on the enthalpy of the plasma stream and the temperature and volume of the cold high pressure converging gas, establishing a net temperature of the gas stream at a temperature such that the powdered material will not melt or soften, and projecting the powder particles at high velocity onto a workpiece surface.

Abstract: A method of operation of a plasma torch and the plasma apparatus to produce a hot gas jet stream directed towards a workpiece to be coated by first injecting a cold high pressure carrier gas containing a powder material into a cold main high pressure gas flow and then directing this combined high pressure gas flow coaxially around a plasma exiting from an operating plasma generator and converging directly into the hot plasma effluent, thereby mixing with the hot plasma effluent to form a gas stream with a net temperature based on the enthalpy of the plasma stream and the temperature and volume of the cold high pressure converging gas, establishing a net temperature of the gas stream at a temperature such that the powdered material will not melt or soften, and projecting the powder particles at high velocity onto a workpiece surface.

Abstract: A method of operation of a plasma torch. A cold high pressure carrier gas containing a powder material is injected into a cold main high pressure gas flow and then this combined flow is directed coaxially around a plasma exiting from an operating plasma generator and converging into the hot plasma effluent, mixing with the effluent to form a gas stream with a net temperature, based on the enthalpy of the plasma stream and the temperature and volume of the cold high pressure converging gas, such that the powdered material will not melt. The combined flow with entrained is directed through a supersonic nozzle accelerating the flow to supersonic velocites sufficient that the particles striking the workpiece achieve kinetic energy transformation into elastic deformation of the particles as they impact the workpiece forming a cohesive coating.

Abstract: A feedstock feeder for supplying feedstock to a system operating at a level of pressure. The feedstock feeder includes a pressure vessel having a pressure which is higher than the level of pressure; a mechanical feeder portion which meters the flow of feedstock to the system, the mechanical feeder portion located within the pressure vessel; a feedstock supplier which supplies feedstock to the mechanical feeder portion, the feedstock supplier located within the pressure vessel; a drive mechanism for driving a dynamically moving portion attached to the drive mechanism, the dynamically moving portion coupled to the mechanical feeder portion for moving the mechanical feeder portion; and wherein all dynamic seals operating to seal about the dynamically moving portion are positioned within the pressure vessel.

Abstract: A feedstock feeder for supplying feedstock to a system operating at a level of pressure. The feedstock feeder includes a pressure vessel having a pressure which is higher than the level of pressure; a mechanical feeder portion which meters the flow of feedstock to the system, the mechanical feeder portion located within the pressure vessel; a feedstock supplier which supplies feedstock to the mechanical feeder portion, the feedstock supplier located within the pressure vessel; a drive mechanism for driving a dynamically moving portion attached to the drive mechanism, the dynamically moving portion coupled to the mechanical feeder portion for moving the mechanical feeder portion; and wherein all dynamic seals operating to seal about the dynamically moving portion are positioned within the pressure vessel.

Abstract: A plasma transferred wire arc thermal spray apparatus and method producing an extended-arc and supersonic plasma jet stream for applying a dense metallic coating on a substrate, such as a concave internal surface of a bore. The apparatus includes a plasma generating torch assembling having a cathode and an anode nozzle surrounding the cathode and a wire feeder which continuously feeds the tip of a wire feedstock opposite a constricted nozzle orifice and wherein the wire feedstock is maintained at the same positive electrical potential as the nozzle. Plasma gas is directed into the nozzle, preferably generating a vortex flow around the cathode and exiting the restricted nozzle orifice. The improved apparatus includes a pilot power supply and a high voltage or high frequency power supply which initiates the electric arc and the constricted plasma arc and a separate main power supply which extends the constricted plasma arc to the wire tip.

Abstract: A plasma transferred wire arc thermal spray apparatus and method producing an extended-arc and supersonic plasma jet stream for applying a dense metallic coating on a substrate, such as a concave internal surface of a bore. The apparatus includes a plasma generating torch assembling having a cathode and an anode nozzle surrounding the cathode and a wire feeder which continuously feeds the tip of a wire feedstock opposite a constricted nozzle orifice and wherein the wire feedstock is maintained at the same positive electrical potential as the nozzle. Plasma gas is directed into the nozzle, preferably generating a vortex flow around the cathode and exiting the restricted nozzle orifice. The improved apparatus includes a pilot power supply and a high voltage or high frequency power supply which initiates the electric arc and the constricted plasma arc and a separate main power supply which extends the constricted plasma arc to the wire tip.

Abstract: A method of thermal spray coating a surface with a metal coating material includes the provision of a nozzle about a thermal spray coating apparatus, such as a two wire electric-arc apparatus. The nozzle includes a plurality of ports facing generally radially inwardly towards a coating material particle stream, such as an atomized molten metal stream of a two-wire arc thermal spray apparatus. The ports sequentially receive a deflecting gas flow, such that the direction moves circumferentially about the axis of the particle stream. The deflecting gas entrains the coating material and carries it radially to the surface of the part to be coated or the nozzle assembly. By utilizing a plurality of valve ports, one simplifies the assembly over prior art systems which have rotated the part to be coated. In one embodiment of this invention, a valve disk selectively communicates a compressed gas to the ports sequentially.

Abstract: A method of thermal spray coating a surface with a metal coating material includes the provision of a nozzle about a thermal spray coating apparatus, such as a two wire electric-arc apparatus. The nozzle includes a plurality of ports facing generally radially inwardly towards a coating material particle stream, such as an atomized molten metal stream of a two-wire arc thermal spray apparatus. The ports sequentially receive a deflecting gas flow, such that the direction moves circumferentially about the axis of the particle stream. The deflecting gas entrains the coating material and carries it radially to the surface of the part to be coated or the nozzle assembly. By utilizing a plurality of valve ports, one simplifies the assembly over prior art systems which have rotated the part to be coated. In one embodiment of this invention, a valve disk selectively communicates a compressed gas to the ports sequentially.

Abstract: A high velocity arc spray apparatus includes a transferred-arc-plasma torch assembly which forms a transferred-arc column. A metal feedstock is fed into the transferred-arc column at an angle such that no portion of the metal feedstock is closer to the transferred-arc-plasma torch assembly than the leading edge of the metal feedstock in the feeding direction. A power source is coupled to both the metal feedstock and transferred-arc-plasma torch assembly for creating an electrical potential difference between the metal feedstock and the transferred torch assembly.