Abstract: The present invention discloses a thermal spray apparatus with improved thermal efficiency and wear resistance in both the nozzle and barrel combustion chamber. Specifically, disclosed herein is a thermal spray apparatus for spraying substrate coatings, comprising a high velocity oxygen fuel (HVOF) gun wherein said gun includes a combustion chamber generating heated flow therefrom and a nozzle downstream from said chamber. The nozzle and/or chamber contain a first layer of material heated by the flow, and a second layer of material which contacts the first layer when said first layer is heated. The first layer has a thermal conductivity that is lower than said second layer and preferably a lower thermal expansion coefficient. In use, the contact of the first heated layer of material with the second layer operates to remove heat from the first layer therein providing automatic/self-regulating temperature control of the HVOF apparatus.

Abstract: An apparatus for coating a part with a metallic coating comprising at least two consumable electrically conductive metallic wire electrodes converging to converging point at their ends, an electric current into said wires creating an arc and melting said wire ends forming an arc ball, an atomizing gas supply supplying gas to said converging point of said wires to convert said arc ball into a molten particle stream, and a deflecting gas valve assembly disposed outwardly of said consumable wires, said deflecting gas valve assembly deflecting gas from a direction which is rotatable relative to said two wires, said deflecting gas valve assembly containing a plurality of ports relative to and behind said molten particle stream supplying a steady flow of deflecting gas thereby deflecting said molten metal particle stream radially outward towards a surface to be coated.

Abstract: A narrow beam arc spray head device includes a convergent-divergent nozzle; a number of wires the paths of which intersect at a point in the nozzle; controller for supplying an electrical current to the wires so that an arc is formed between the wires causing a portion of at least one of the wires to melt; a primary axial gas stream impinging upon the wire path intersection to cause the molten metal to be carried axially away from the area of the intersection; and a secondary gas stream forming a generally conical sheath around the axial gas stream in the divergent portion of the nozzle; whereby the primary gas stream and the secondary gas stream emerge from the nozzle as substantially coaxial gas streams thus tending to concentrate the flow of the molten metal carried by the coaxial streams. The spray head device may also include a regulator for regulating the secondary gas stream relative to the primary axial gas stream.

Abstract: A metal spray gun of the arc spray type has a nozzle-positioner member of electrically insulating material that is disposed between a gas inlet and an arc zone. A primary stream of gas is flowed through a through passage in the nozzle-positioner member, and seat surfaces in the through passage receive tips of individual electrically conductive contact tube assemblies that are biased outwardly away from one another. The nozzle-positioner member aligns the contact tube assemblies and configures the gas stream such that each metal wire is immediately enveloped in gas flow as it emerges from its contact tube and remains in that enveloping gas flow throughout the region between the contact tube tip and the arc zone. The spray gun produces quality metal spray coatings with lower gas pressures and has lower noise levels.

Abstract: The present invention discloses a thermal spray apparatus with improved thermal efficiency and wear resistance in both the nozzle and barrel combustion chamber. Specifically, disclosed herein is a thermal spray apparatus for spraying substrate coatings, comprising a high velocity oxygen fuel (HVOF) gun wherein said gun includes a combustion chamber generating heated flow therefrom and a nozzle downstream from said chamber. The nozzle and/or chamber contain a first layer of material heated by the flow, and a second layer of material which contacts the first layer when said first layer is heated. The first layer has a thermal conductivity that is lower than said second layer and preferably a lower thermal expansion coefficient. In use, the contact of the first heated layer of material with the second layer operates to remove heat from the first layer therein providing automatic/self-regulating temperature control of the HVOF apparatus.