Abstract: A system for assuring a more even powder flow rate in a flame spray gun. A powder metering device entrains powder into a gas. The gas with entrained powder is coupled to the flame spray gun. Vibration means, coupled to the powder and gas conduit, is provided to prevent any powder from settling in the conduit.

Abstract: A plasma flame spray gun suitable for being constructed physically smaller than comparable power prior art plasma flame spray guns. The gun includes a nozzle having a tapering portion on the inlet side thereof. A cathode with a flat tip is positioned to at least partially extend into the tapering portion of the nozzle. A gas distribution ring is located around the cathode for creating a vortex around the cathode tip. This causes the arc formed between the tip and the nozzle to have a root which spins around the perimeter of the nozzle tip resulting in less wear and, therefore, extended part life.

Abstract: A heavy duty plasma spray gun for extended industrial service is disclosed. The gun includes a gas distribution member made of a material having a coefficient of expansion different from that of the parts surrounding it. The gas distribution member is forcibly urged by a resilient member such as a coiled spring against a seal so as to assure the plasma gas is introduced into the gun arc in a manner only defined by the gas distribution member. The gun has liquid cooling for the nozzle (anode) and the cathode. Double seals are provided between the coolant and the arc region and a vent is provided between the seals which provides an indication when a seal has failed. Some parts of the gun are electrically isolated from others by an intermediate member which is formed as a sandwich of two rigid metal face pieces and an insulator disposed between them. The metal face pieces provide a rigid body to attach the remaining parts in proper alignment therewith.

Abstract: A plasma spray gun nozzle with a thin annular coolant passage having extended life. The thin annular passage is located adjacent a thin nozzle wall which confines the arc formed in the nozzle. The dimensions of the thin annular passage and the wall thickness are selected to assure maximum nozzle life.

Abstract: A flame spray powder comprising particles with a central core of a material selected from the group consisting of zirconium oxide, magnesium oxide, hafnium oxide, cerium oxide, yttrium oxide and combinations thereof. The core then has discrete aluminum particles in a binder deposited therein to form the flame spray powder which may be flame sprayed produce an abradable and erosion resistant coating.

Abstract: A flame sprayable powder composition suitable for coating a plastic substrate comprising by weight (a) about 90 to 98% of a flame sprayable mineral powder, (b) about 1 to 5% of a nylon powder, and (c) about 1 to 5% of an epoxy resin powder. The coated plastic may thereafter be overcoated by flame spraying with conventional metal or ceramic powders. The undercoat results in a good bond to the substrate.

Abstract: A flame spraying device including a rocket accelerator wherein a low velocity flame is produced into which a coating material is introduced. At least one rocket accelerator producing a high velocity stream of combustion product gases is positioned relative to the low velocity flame so that the coating material carried thereby is accelerated toward the substrate to be coated. By positioning the rocket relative to the low velocity flame, the dwell time in the low velocity flame can be optimized to produce the best coating of a substrate. The coating quality is also enhanced by the fact that the coating material does not oxidize or cool significantly while in the high velocity stream and by the fact that the coating material strikes the substrate at high speed thereby resulting in high density coating.

Abstract: A self-bonding flame spray wire capable of forming a readily grindable coating formed of a sheath of aluminum and a compacted powder core containing a major portion of nickel and stainless steel and a minor portion of aluminum and metal oxide. The core may contain from about 10 to 90 percent, and preferably about 61 percent, by weight nickel, about 10 to 90, and preferably 30, percent by weight stainless steel, from 1 to 10 percent by weight, and preferably 5 percent by weight, aluminum, from 1/4 to 10 percent by weight, and preferably 4 percent by weight, of the metal oxide which may, for example, be cobalt oxide or zirconium oxide, and is most preferably zirconium oxide.

Abstract: A flame spray powder comprising particles having a core of nickel, iron, copper, cobalt or alloys thereof coated with a binder containing discrete particles of aluminum and substantially pure nickel. The core material should be present in amounts of 70-98, and preferably 80-94, weight percent of the total metal content of the powder. The core particles should range in size between -60 mesh and +3 microns, and preferably -100 mesh and +400 mesh. The core material is most preferably nickel, and the coating may, in addition to the aluminum and nickel, contain molybdenum.

Abstract: Method and apparatus for plasma flame-spraying coating material onto a substrate by means of passing a plasma-forming gas through a nozzle electrode, passing an arc-forming current between said nozzle electrode and a rear electrode to form a plasma effluent, introducing coating material into the plasma effluent, passing the plasma effluent axially through a wall shroud extending from the exit of said nozzle electrode and forming a flame shroud for the plasma effluent at least within the wall shroud.

Abstract: Method and apparatus for plasma flame-spraying coating material onto a substrate by means of passing a plasma-forming gas through a nozzle electrode, passing an arc-forming current between said nozzle electrode and a rear electrode to form a plasma effluent, introducing spray coating material into the plasma effluent, passing the plasma effluent axially through a wall shroud extending from the exit of said nozzle electrode and forming a hot gas shroud for the plasma effluent at least within the wall shroud.

Abstract: A flame-sprayable flexible wire comprising a mineral powder having a particle size of less than about 140 mesh and about 5 to 70% by volume of the wire of a polyurethane or epoxy polymer. Advantageously the wire is produced by forming the requisite mixture plus a curing agent, effecting a partial cure in a sheet form, crumbling the sheet to coarse granules and extruding the granules to form the wire. The mineral powder particles may first be coated with a surface active resin such as a silicone which promotes adhesion to the polymer and which protects the polymer from the degradative effect of the mineral. The preferred surface active resins are silicones. The wire retains its strength and flexibility over long periods of time and produces high quality flame sprayed surfaces.

Abstract: An arc spray gun in which the ends of two metal wires, respectively connected to opposite terminals of a DC power source, are fed to an intersection point to strike and maintain an electric arc, melting the wires. A gas jet directed at the intersection point sprays the molten metal onto the object to be coated. The wire connected to the positive terminal of the power source is of larger diameter than the negative-terminal-connected wire. Parallel guides are provided for feeding the wires through hollow electrodes converging toward the arc-melting zone, the guide path of the larger wire being straighter than that of the smaller wire.

Abstract: A flame spray material in the form of a composite comprising (1) as a first component an alloy containing at least about 40% of its weight of at least one of nickel and cobalt, and about 1 to 6% by weight of boron, and (2) aluminum powder as a second component, the first component being present in about 66 to 99% by weight of the composite. The material, desirably blended with about 10% of an aluminum-molybdenum-coated nickel core powder, produces self-bonded wear resistant coatings which can be ground without cracking.

Abstract: A composite flame spray powder comprising powder particles having as components, cast iron, molybdenum (as such and/or as ferromolybdenum), and boron (as such and/or as ferroboron), unalloyed together. The composite particles are preferably in a form having a cast iron core, of a size between -170 mesh standard screen size and +15 microns, with particles of molybdenum and boron of a size between about -20 and +0.1 microns, bound to the surface of the cast iron core with a binder, the molybdenum being present in amounts of about 20% by weight and the boron in amounts of about 1% by weight based on the total of the cast iron and molybdenum. When flame sprayed, the composite particles produce a coating having high wear and scuff resistance characteristics and low friction.

Abstract: A device for feeding metal powders suspended in a conveying gas uniformly and controllably to a point of utilization such as a flame spray gun comprising an enclosed hopper which contains the powder in particulate loose and by and large unfluidized form and is supplied in its upper portion with a controlled amount of fluidizing gas. A conduit with a downwardly opening powder intake conduit passes through the lower portion of the hopper and is supplied with a conveying gas at a pre-determined rate. The fluidizing gas passes through the mass of solids and is diffused thereby. It converges towards the orifice, suspends the powder in the vicinity of the orifice, upturning into the orifice to do so, and propels the fluidized powder therethrough into the conveying gas. The amount of fluidizing gas flow determines the amount of solids placed in the conveying gas. The fluidizing gas flow is controlled inversely responsive to the pressure at a point in the conveying gas line.

Abstract: An improvement in a process for high velocity plasma flame-spraying of a powder onto a workpiece wherein an unlit plasma gas is passed through the nozzle of a plasma flame-spraying gun at a high velocity of at least 90 meters per second and an electric arc is struck between an electrode within said gun and a portion of said nozzle and powder is fed into the resultant flame exteriorly of said nozzle and said gun, which improvement comprises increasing the deposit efficiency of the coating of the powder onto the workpiece by carrying out said process such that the power through said electric arc is at least 15 kilowatts, disposing the arc created at the exit rim of said nozzle by regulating the gas velocity, length of nozzle and diameter of nozzle bore such that said arc is established at said exit rim of said nozzle, especially a process wherein a gas back pressure is maintained within said nozzle which is greater than 1 atmosphere gauge, the ignited plasma gas has an enthalpy of at least 7000 joules/standard

Abstract: An improvement in a plasma flame spraying apparatus, particularly one in which at least two gases form the plasma, which improvement comprises means associated with the plasma gas inlet, said means being time related to an increase in the current through the arc maintained in the plasma flame spray gun, said current and said means associated with the plasma gas inlet each independently being associated with a timing means whereby the full flow of a secondary gas through the nozzle of the gun and the electric arc established therein is substantially simultaneous with an establishment of a full current level through the electric arc through which said secondary gas passes; a fully automatic ignition system for a plasma gas flame spraying process whereby establishment of an optimum gas mixture for normal operation is time coordinated with respect to start-up of the current passing in the circuit of the electric arc in the gun, such that the current rise and rise of secondary gas flow through the gun occur within

Abstract: A flowmeter for measuring the quantitative flow of fluids such as gases passing therethrough is disclosed and includes a housing forming at its upper end a centrally located tubular guide. The housing has a centrally located chamber which terminates at its upper end at the tubular guide. The chamber is in communication with a gas outlet. A gas tube is mounted in the chamber and has a fluid escape slot which opens to the chamber. The gas tube communicates at its lower end with a gas inlet. A float is provided which is adapted to slidably move up and down within the gas tube and the tubular guide of the housing. A sight glass is mounted on the upper portion of the housing co-axial with the float for viewing movement of the upper portion of the float therein. The sight glass is sealed at its upper end forming fluid shock absorbing means to accommodate and compensate for rapid upward and downward movement of the float.