Abstract: An arc spray apparatus includes a spray gun body with a pair of converging wire guides to guide two feeding metal wires to a region of contact at the wire tips where an arc melts the tips. A gas jet member has a projection extending forwardly from the gun body and offset laterally from a guide plane defined by the axes of the wire guides. The projection has a primary orifice to issue a primary gas jet directed laterally to the point of contact for atomization of the molten metal and production of a spray stream at an angle to the guide plane, preferably perpendicular. A plurality of at least four secondary orifices are arcuately spaced about the primary orifice. The secondary orifices effect secondary gas jets substantially parallel to the primary jet, so that the spray stream is constricted by the secondary gas jets.

Abstract: In a two-wire arc spray extension two metal wires are guided into contact, and a gas cap is affixed to a gun body. The feeding wires receive an arc current to effect an arc and thereby molten metal at the wire tips. The gas cap has a plurality of orifices therein that receive pressurized gas to generate gas jets. The orifices are disposed with substantially equal spacing arcuately such that the jets are directed with a radially inward component toward the tips to effect atomization of the molten metal into a spray stream. The orifices have axes that are offset forwardly and tangentially from radial so as to create a vortex flow such that the spray stream is effected in the form of a conical fan. Insertion of the spray stream centrally into a hole can effect a coating circumferentially on an inside surface of the hole.

Abstract: A thermal spray powder consists of nickel, chromium and carbon. The chromium consists of a first portion and a second portion, the nickel being alloyed with the first portion in an alloy matrix. The second portion and the carbon are combined into chromium carbide substantially as Cr.sub.3 C.sub.2 or Cr.sub.7 C.sub.3 or a combination thereof, with the chromium carbide being in the form of precipitates between 0.1 .mu.m and 5 .mu.m distributed uniformly in the alloy matrix.

Abstract: A figure eight mechanism moves a thermal spray gun over a substrate such that the deposit pattern has a figure eight configuration. The mechanism and thereby the thermal spray gun and the pattern are traversed along the substrate. The mechanism is such that, when driven by an input drive of constant speed, the deposit travels along the configuration at a non-uniform velocity. A drive system provides an input drive with varying speed so as to reduce the non-uniformity of the velocity. In one aspect a motor has varying speed, and in another aspect a linkage between a constant speed motor and the mechanism provides the varying speed.

Abstract: A gas cap for a thermal spray gun has a spray passage extending from the combustion chamber to an exit end, and a thermal spray material is fed into the passage. A nozzle component of the gas cap is formed of a tubular inner member in thermal contact with a metallic outer member, such as copper, that is in contact with a fluid coolant. The inner member is formed of a hard, thermally conductive material, preferably a carbide in a metal matrix, such as tungsten carbide in cobalt.

Abstract: A granular composition is applied to tips of rotor blades utilized in a gas turbine engine wherein the blade tips rub against an abradable ceramic layer. Individual grains each have a core of silicon carbide and a layer of aluminum nitride on the core. A layer of a cladding metal may be bonded to the aluminum nitride. The composition also may include particles of cubic boron nitride and/or particles of metal alloy blended with the grains of silicon carbide.

Abstract: An arc spray gun has a pair of tubular wire guides that guide two metal wires to a point of contact at the wire tips where an arc current through the wires effect an arc, thereby melting the tips. Primary gas channeling on a central axis issues a primary gas flow that atomizes the molten metal and effects a spray stream thereof. A gas cap has at least four orifices arcuately spaced equally about the central axis. The orifices direct secondary gas jets inwardly with a forward directional component toward a point of intersection of the orifice axes on the central axis. The point of intersection is located proximate the point of contact and spaced downstream therefrom sufficiently for the jets not to interfere substantially with the atomization. The spray stream thereby is constricted and accelerated by the secondary gas jets.

Abstract: A wire thermal spray gun such as a two-wire arc gun has a speed regulator for a DC pull motor in the gun. Armature current corresponds to pulling torque on the pull motor depending on load resistance of the wires. A DC push motor is between a wire supply and the gun, with wire conduits connecting to the gun. A controller provides the push motor with a controlled pushing torque. Feedback of the armature current of the pull motor to the controller adjusts the pushing torque in direct response to change in the pulling torque, such that load sharing is maintained between the push motor and the pull motor.

Abstract: A single cathode plasma gun injects powder therein so that the powder exits along a central axis of an exit barrel of the gun, in order to provide improved coatings of the powder material on a workpiece. The central axis of the single cathode extends from an arc chamber and intersects with the central axis of the exit barrel so as to form an acute angle which is substantially greater than 0.degree. but no greater than 90.degree.. Examples of the acute angle include 45.degree. and 10.degree.. A powder feed passage extends along an axis which may be coincident with the central axis of the exit barrel or may form an angle with the central axis of the exit barrel of as much as 45.degree.. Consequently, the axis of the powder feed passage forms an angle with the central axis of the single cathode which is at least as great as the acute angle between the central axes of the single cathode and the exit barrel.

Abstract: A composite thermal spray powder, for producing abradable coatings, is substantially in the form of clad particles each of which has a core particle of boron nitride and subparticles of aluminum-silicon alloy. The subparticles are bonded to the core particle with an polymeric binder.

Abstract: A cooling fixture for thermal spraying includes a rotatable tubular member for supporting a tubular substrate such as for an oxygen sensor. A cooling tube extends from the tubular member into an open end of the substrate so as to delimit an annular channel therein. The other end of the substrate is closed. Air is forced through the cooling tube into the substrate and thence out via the annular channel, to cool the substrate during thermal spray coating of the outside surface.