Abstract: Methods and apparatus for reducing the TPM level of a diesel engine exhaust stream by providing a suitable oxidation catalyst into the exhaust train. The oxidation catalyst may be incorporated into a thermal insulative coating on the inner surface of the exhaust train, particularly the exhaust manifold and exhaust pipes prior to the turbocharger. Alternatively, when the exhaust train includes a turbocharger, the catalyst can be in a separate monolithic unit between the engine and the turbocharger. The system may also include an improved diesel oxidation catalyst unit having a metal monolithic substrate. The oxidation catalyst can also be incorporated into a thermal insulative coating inside the cylinders, particularly on non-rubbing surfaces such as The invention also includes the use of a protective mullite top coat on the thermal coating. A further embodiment is the use of a stainless steel bond coat to bind the thermal coating to a metallic substrate, particularly an aluminum substrate.

Abstract: Methods and apparatus for reducing the TPM level of a diesel engine exhaust stream by providing a suitable oxidation catalyst into the exhaust train. The oxidation catalyst may be incorporated into a thermal insulative coating on the inner surface of the exhaust train, particularly the exhaust manifold and exhaust pipes prior to the turbocharger. Alternatively, when the exhaust train includes a turbocharger, the catalyst can be in a separate monolithic unit between the engine and the turbocharger. The system may also include an improved diesel oxidation catalyst unit having a metal monolithic substrate. The oxidation catalyst can also be incorporated into a thermal insulative coating inside the cylinders, particularly on non-rubbing surfaces such as The invention also includes the use of a protective mullite top coat on the thermal coating. A further embodiment is the use of a stainless steel bond coat to bind the thermal coating to a metallic substrate, particularly an aluminum substrate.

Abstract: A powder pickup device has a tube formed of an elastomeric tube wall with an orifice therein receptive of powder from a vessel so as to direct powder into a carrier gas in a central passage in the tube. A tubular shell supports the tube and has an aperture therein aligned with the orifice. In another embodiment the tube is combined of a rigid tube and an elastomeric tube fitted tandemly in the shell. The rigid tube extends to an inner end proximate the aperture and has the orifice situated therein. The elastomeric tube extends from the rigid tube and is disposed so as to place a section thereof opposite the orifice.

Abstract: A superconductive oxide powder is produced by a method comprising spray drying a slip to form agglomerates, feeding the agglomerates sequentially through a first and a second oxygen supported combustion flame for fusing the fine particles in the agglomerates to form an intermediate powder, annealing the intermediate powder in an oxygen-containing environment such as to produce a friable mass, and crushing the mass to form the superconductive oxide powder. For example, a precursor compound in the slip is barrium carbonate, the other precursor constituents are yttrium oxide and copper oxide, and the yttrium, barium and copper in atomic proportions in the precursor constituents are 1:2:3+Y where Y denotes a copper surplus having a value of up to about 1.5. In the final powder the proportions are 1:2:3+Z where Z is between about 0.2 and 1.0.

Abstract: Two constituent powders of a powder blend for thermal spraying are in the form of composite particles containing subparticles of nickel alloy and benoite for clearance control coatings. The composite particles are formed by spray drying. In one embodiment the volume percentage of metal in one constituent powder is at least 25% greater than in the other powder. In another embodiment the difference is about 10% by volume, and the alloy rich constituent has alloy subparticles sufficiently large to act as core particles to which the finer subparticles of bentonite are bonded.

Abstract: A rotor blade is for a gas turbine engine having a plurality of rotor blades and a substantially coaxial shroud encompassing the tips of the blades. A ceramic layer is bonded to the blade tip, the ceramic layer consisting of a combination of aluminum oxide and zirconium oxide or at least partially stabilized zirconium oxide. The ceramic layer is formed as a plasma sprayed coating or a high velocity oxy-fuel sprayed coating.

Abstract: A gas cap for a thermal spray gun has a passage therethrough including an entrance channel, an exit channel, and an intermediate channel connecting between the entrance and exit channels. The entrance channel is cylindrical on an entrance axis, and the exit channel is convergingly conical on an exit axis oriented at 45.degree. to the entrance axis. The intermediate channel is symmetrical to the plane of the entrance and exit axes and has a near portion and a far portion. The near portion is semicylindrical about the entrance axis, and the far portion is semicylindrical about a far axis segment lying in the plane. That segment is offset from the entrance axis away from the exit end of the gas cap, and is oriented at 14.degree. to the entrance axis, the three axes intersecting at a common point.

Abstract: Manufacture of glass mold plungers utilizes a thermal spray gun having combustion chamber with an open channel for propelling combustion products into the ambient atmosphere at supersonic velocity. The method comprises injecting into the chamber a combustible mixture of combustion gas and oxygen at a pressure in the chamber of at least two atmospheres above ambient atmospheric pressure, feeding into the chamber a powder comprising self-fluxing alloy particles, and combusting the combustible mixture in the chamber means whereby a supersonic spray stream containing the powder is propelled through the open channel. The spray stream is directed toward a glass mold plunger substrate such as to produce a coating thereon which is ground and polished. The coating may be fused prior to grinding.

Abstract: A method for producing a dense and tenacious coating with a thermal spray gun including a nozzle member and a gas cap. The gas cap extends from the nozzle and has an inwardly facing cylindrical wall defining a combustion chamber with an open end and an opposite end bounded by the nozzle. An annular flow of a combustible mixture is injected at a pressure of at least two bar above atmospheric pressure from the nozzle coaxially into the combustion chamber. An annular outer flow of pressurized air is injected from the nozzle adjacent to the cylindrical wall. Powder particles having a heat-stable, non-fusible component and a heat-softenable component, and entrained in a carrier gas, are fed axially from the nozzle into the combustion chamber. An annular inner flow of pressurized air is injected from the nozzle into the combustion chamber coaxially between the combustible mixture and the powder-carrier gas.

Abstract: A powder or wire thermal spray gun, useful for spraying a low oxide coating of oxidizable material, comprises a nozzle member with a nozzle face, and a gas cap extending from the nozzle member and having an inwardly facing cylindrical wall defining a combustion chamber with an open end for propelling combustion products into the ambient atmosphere at supersonic velocity and an opposite end bounded by the nozzle face. An annular flow of a combustible mixture is injected from the nozzle member coaxially into the combustion chamber at a pressure therein sufficient to propel combustion products of the mixture from the open end at supersonic velocity. A first annular flow of inert gas is injected adjacent to the cylindrical wall radially outward of the annular flow of the combustible mixture.

Abstract: A thermal spray gun, for spraying wire and powder simultaneously at high velocity to produce a dense and tenacious coating, comprises a nozzle and a gas cap extending from the nozzle. Combustible gas is injected from the nozzle coaxially into the combustion chamber in the gas cap. An annular outer flow of pressurized air is injected into the chamber adjacent to the gas cap. Heat fusible wire is fed axially from the nozzle into the combustion chamber. An annular inner flow of pressurized air is injected into the combustion chamber adjacent to the wire. Powder in a carrier gas is fed annularly from the nozzle into the combustion chamber coaxially between the combustible mixture and the inner flow, such that a spray stream containing the powder and the heat fusible material commingled in finely divided form is propelled through the open end.

Abstract: A plasma gun apparatus with precision adjustment of arc voltage, includes a gun body with a bore therethrough, a nozzle anode in the bore, a cathode holder engaged in the bore with threads, and a cathode mounted on the cathode holder. A locking ring is engaged in the bore with threads for locking the cathode holder. An inner wrench is formed of a handle attached to a shaft inserted through a hole in the locking ring and engaged with the cathode holder to rotate the same for axial positioning. A sleeve wrench is disposed coaxially over the shaft and engaged with the locking ring. The handle and the sleeve wrench each has a plurality of angular position markings thereon mutually alignable to provide rotational reference for precision positioning of the cathode holder.

Abstract: A method of and apparatus for producing a dense and tenacious coating with a thermal spray gun including a nozzle member and a gas cap. The gas cap extends from the nozzle and has an inwardly facing cylindrical wall defining a combustion chamber with an open end and an opposite end bounded by the nozzle. An annular flow of a combustible mixture is injected at a pressure of at least two bar above atmospheric pressure from the nozzle coaxially into the combustion chamber. An annular outer flow of pressurized air is injected from the nozzle adjacent to the cylindrical wall. Heat fusible powder entrained in a carrier gas is fed axially from the nozzle into the combustion chamber. An annular inner flow of pressurized air is injected from the nozzle into the combustion chamber coaxially between the combustible mixture and the powder-carrier gas. Upon combusting the annular mixture a supersonic spray stream containing the powder is propelled through the open end to produce a coating.

Abstract: A gas distribution ring for a plasma gun comprises a ring member with two sets of gas inlet orifices extending from the outer surface inwardly through the ring member. The outer surface has an undulated groove for an O-ring formed therein, and the orifices are positioned with respect to the undulated O-ring such that one set of orifices are isolated on one side of the O-ring and the other set of orifices are isolated on the other side of the O-ring. In a preferred embodiment the orifices of one set are radial with respect to the axis of the ring, and the orifices on the other side of the undulated O-ring have a tangential component to provide vortical gas flow in the arc region of the gun. The gas distribution ring positioned in the plasma spray gun permits a simple choice between radial and vortical flow in the arc region of the gun, without alteration of the gun.

Abstract: Plural powders are supplied to one or more torches from different fluidized-powder zones, and plural independent lines through each of these zones enable each torch to be supplied with one or more independent lines of powder flow to the nozzle-discharge region of each torch.

Abstract: A flame spray system comprising a torch is provided having a gas mixing chamber and means for feeding acetylene and oxygen to the mixing chamber in a preselected proportion. The system includes acetylene valve means with an orifice restrictor for feeding the gas to a mixing chamber, the orifice size being selected to provide, in the choked state, a flow of acetylene therethrough under a selected choke pressure.

Abstract: The invention contemplates a powder-feeding system for gas-propelled delivery of a powder to be controllably supplied, as to a flame-spraying gas torch or to a transferred-arc plasma torch. A fluidizing chamber receives (a) fluidizing-gas flow from below a porous screen, and (b) a restricted gravitational flow of powder at a relatively small central discharge location above the porous screen. A gas conduit extends transversely through the chamber between the powder-discharge location and the porous screen; it has a carrier-gas supply connection at one end and a gas-propelled powder-delivery connection at its other end. The conduit also has an upwardly extending opening virtually beneath and facing the powder-discharge location, but a shed interposed between this opening and the powder-discharge location sufficiently overlaps the opening to assure that no powder will pass through the opening and into the conduit unless it has been gas-fluidized.

Abstract: The invention contemplates a plasma-transferred-arc torch construction wherein, optionally, a single releasable clamp enables rapid separation of downstream-end fittings of an anode subassembly and a cathode subassembly, as for inspection, servicing and/or replacement; in an alternative option, release of the single clamp enables rapid further disassembly of the entirety of the respective subassemblies from mounting structure which includes the single clamp. These options are available for torch structure incorporating provision for sealed independent fluid-flow supplies of (a) coolant serving both electrode subassemblies, (b) plasma gas serving an annular interelectrode gap at the downstream end of the torch, (c) a metallic, ceramic or other powder fluidized in a carrier gas, for torch-deposition of the powder, and (d) a shielding gas to protect the zone of plasma-transfer of the arc and any powder conveyed therewith.

Abstract: The invention contemplates improved nozzle structure removably securable to a gas-distributor body for delivering and discharging independent flows of combustible-gas mixture and of powder material to be flame-sprayed by a gas torch to which the nozzle is fitted. The combustible-gas mixture is successively accommodated in annular manifold regions of relatively large sectional area, respectively upstream and downstream from an intermediate annular manifold region of relatively restricted sectional area, for inhibiting flash-back to the gas distributor and for effectively limiting any flash-back effects to the manifold region downstream of the annular restriction.

Abstract: The invention contemplates a powder-feeding system for gas-propelled delivery of a powder to be controllably supplied, as to a flame-spraying gas torch or to a transferred-arc plasma torch. A fluidizing chamber receives (a) fluidizing-gas flow from below a porous screen, and (b) a restricted gravitational flow of powder at a relatively small central discharge location above the porous screen. A gas conduit extends transversely through the chamber between the powder-discharge location and the porous screen; it has a carrier-gas supply connection at one end and a gas-propelled powder-delivery connection at its other end. The conduit also has an upwardly extending opening virtually beneath and facing the powder-discharge location, but a shed interposed between this opening and the powder-discharge location sufficiently overlaps the opening to assure that no powder will pass through the opening and into the conduit unless it has been gas-fluidized.