Abstract: The profiled surface is used as an abradable (1) in flow machines such as gas turbines where blade tips (2) move over the profiled abradable in a predetermined direction (v) to produce a partial abraded surface which is formed by material removal or ablation. The surface is formed by ribs (15) which surround chamber-like depressions (11) and extend in rib directions. The abradable (1) forms a pattern of strip-like elements (5) which lie in the directions of the ribs on connection lines (45) between corner points (41, 42; 43, 44) of a reference grid (40). Over at least more than 80-90% of the abraded surface the rib direction differs from the direction of movement (v) of the blade tips (2). For at least two-thirds of the abraded surface the direction of movement deviates from the rib direction by more than 30°, preferably more than 45°. The strip-like elements (5) of the abraded surface can be curved as well as discrete and/or partly connected strips.

Abstract: A plasma spraying apparatus is provided comprising a plasma gun shaft member and a plasma gun head member, connected to the plasma gun shaft member and adapted to create a plasma torch escaping radially from the head member. In order to enable the plasma gun head member and, thereby, those parts and elements thereof that are subject to wear quickly and easily, the plasma gun head member is of modular design. For fixing the plasma gun head member to the plasma gun shaft member, the electrical contact elements provided for transmitting electrical power on the plasma gun head member are used. These electrical contact elements tower above that front face of the plasma gun head member that is intended to be connected to the plasma gun shaft member. Clamping the head member to the shaft member is accomplished by means of quick release lever members provided on the shaft member. That lever members are provided with eccentric portions engaging recesses provided on the electrical contact elements.

Abstract: To improve the machining and processing, respectively, as well as the tribologic properties of ferrous coatings for the working surfaces of combustion engine cylinder blocks applied by a plasma spraying operation, a ferrous coating having a content of bound oxygen in the amount of between 1 to 4% by weight is suggested. Such coatings can be realized, for example, by adding an amount of 200 to 1000 normalized liters air per minute during the plasma spraying operation.

Abstract: A plasma spraying assembly comprising a treatment chamber and a plasma spraying device located in the interior thereof is disclosed that further comprises an assembly for controlling the gas flow in the interior of the treatment chamber. In order to prevent a gas flow in the interior of the treatment chamber that whirls deposits to be created, a deflection device is provided that is located at least partially in the interior of the treatment chamber. Vertically below the treatment chamber, a collecting shaft is located. In the region between the treatment chamber and the collecting shaft, there is provided a basic element comprising baffle members, but leaving open a passage between the treatment chamber and the collecting shaft. In the interior of the collecting shaft, a deflection element is located having essentially conical shape and towering into the passage of the basic element. The collecting shaft is in operative connection with the suction side of a blower and with a vacuum pump.

Abstract: The profiled surface is used as an abradable (1) in flow machines. In these machines blade tips (2) move over the profiled abradable in a predetermined direction (v). In so doing they produce a partial surface, an abraded surface (10), which is formed by material ablation. The profiling of the surface is formed by ribs (15) which surround chamber-like depressions (11). A rib direction can in each case be associated with the ribs. The abradable (1) forms a pattern which is built up of strip-like elements (5) and the elements of which lie in the directions of the ribs on connection lines (45) between corner points (41, 42; 43, 44) of a reference grid (40). Largely at each location of the abraded surface (10)—i.e. at least at more than 80 - 95% of the abraded surface—the rib direction differs from the direction of movement (v) of the blade tips (2).

Abstract: The nozzle is provided with a plurality of cooling channels running from an annular channel located in an inlet region of the nozzle through the nozzle in longitudinal direction up to an outlet region of the nozzle. The powder supply channels provided for the supply of coating material are led between the cooling channels. A nozzle support member adapted for receiving the nozzle is provided with cooling ducts that are hydraulically connected to the cooling channels of the nozzle and constitute therewith a nozzle cooling circulation system. The advantages of this design can be seen in the facts that the nozzle is homogeneously and efficiently cooled up to its outlet end and that the danger of building-up molten deposits within the nozzle is substantially avoided.

Abstract: To provide a substrate consisting of carbon or non-metallic materials containing carbon with a layer of a metal having a high melting point, first an undercoat layer is applied to the substrate by plasma spraying in an inert atmosphere. The undercoat layer predominantly consists of rhenium, molybdenum, zirconium, titan, chrome, niobium, tantalum, hafnium, vanadium, platinum, rhodium or iridium. Onto that undercoat layer, a covering layer can be applied, by plasma spraying as well. In order to reduce the thermo-mechanical stress and to improve the adhesion of the undercoat layer on the surface of the substrate, the substrate is preheated prior to applying the undercoat layer. By means of such a method, carbon-containing substrates can be provided with an undercoat layer and, if required, with a covering layer quickly and reliably at low costs.

Abstract: The indirect plasmatron comprises a neutrode assembly comprising a plurality of plate-shaped electrode members which are electrically insulated from each other. In its interior, the neutrode assembly defines an elongated plasma channel. The outlet aperture for the plasma torch is in the shape of an elongate slot and extends parallel to the central longitudinal axis of the plasma channel. Each of the two electrodes of the plasmatron is surrounded by a cavity through which an inert gas can be fed into the plasma channel. For the purpose of stabilizing the electric arc, at least one pair of permanent magnet members is provided. Their magnetic field exerts a force onto the electric arc which is directed opposite to the force exerted onto the electric arc by the flow of the plasma gas. Particular neutrodes are provided with a channel for feeding a further gas into the plasma channel.

Abstract: In order to render it possible to give a forecast relating to the quality of a coating layer applied to a substrate by a thermal coating apparatus, an apparatus is provided, comprising a plurality of sensors and/or comprises optical means, in order to separately monitor the radiation emitted by the heated particles entrained by the coating jet in particular areas along a section of the coating jet extending crosswise to the direction of the coating jet. The apparatus further comprises electronic circuitry connected to the outputs of the sensors for further processing the measured values. By means of such an apparatus, the coating jet can be systematically and representatively scanned and monitored. On the basis of the signals supplied by the sensors, the spatial distribution of the intensity of the electromagnetic radiation emitted by the heated particles can be determined and can be used as a relevant parameter for qualitatively judging the coating layer or for regulating the coating process.

Abstract: A nozzle for the head of a plasma torch comprises a central aperture and is provided with a plurality of cooling channels uniformly distributed around the central longitudinal axis of the nozzle in a polar configuration. Each of the cooling channels comprises a first cooling channel portion and a second cooling channel portion communicating with the first one and enclosing an angle between each other. The first cooling channel portions extend radially towards the central longitudinal axis of the nozzle and at least approximately perpendicularly thereto. The second cooling channel portions extend under an acute angle with respect to the central longitudinal axis. By this design, a substantially more uniform and more effective cooling of the nozzle is achieved, with the result that the useful working life is prolonged.

Abstract: A plasma system forms a dense, uniform coating of metallic oxide or other material on a relatively large substrate of metal foil or other composition located a substantial distance from the plasma gun so that the plasma stream covers the entire width of the substrate. A large pressure differential between the pressure inside the plasma gun and the ambient pressure outside of the plasma gun creates a shock pattern within the exiting plasma stream so as to disperse the plasma stream and maintain a high energy level therein, as well as thoroughly mixing a coating material introduced into the plasma stream within the gun. Mixing of the coating material within the plasma stream is further enhanced by introducing the coating material into the plasma stream either in liquid form or in the form of very small particles. In one arrangement, the plasma stream is delivered in a long, narrow configuration across the width of the substrate by a nozzle with a slit-like opening at the lower end of the plasma gun.

Abstract: A plasma system forms a dense, uniform coating of metallic oxide or other material on a relatively large substrate of metal foil or other composition located a substantial distance from the plasma gun so that the plasma stream covers the entire width of the substrate. A large pressure differential between the pressure inside the plasma gun and the ambient pressure outside of the plasma gun creates a shock pattern within the exiting plasma-stream so as to disperse the plasma stream and maintain a high energy level therein, as well as thoroughly mixing a coating material introduced into the plasma stream within the gun. Mixing of the coating material within the plasma stream is further enhanced by introducing the coating material into the plasma stream in the form of very small particles. In one arrangement, the plasma stream is delivered in a long, narrow configuration across the width of the substrate by a nozzle with a slit-like opening at the lower end of the plasma gun.

Abstract: The invention provides an apparatus for sand-blasting the inner walls of bores, tubes, pipes and the like, comprising a housing with a first tube member for feeding blasting material and a second tube member for feeding pressurized air. The second tube member is provided with a curved end portion, the orifice thereof being located beyond the outlet opening of the first tube member. The second tube member, together with its end portion, is rotatable around the central longitudinal axis of the first tube member. Thus, the stream of blasting material escaping from the outlet of the first tube member is deflected and accelerated under the influence of the stream of pressurized air escaping from the curved end portion of the second tube member. Due to the provision of such a touchless deflection, the wear of the apparatus can be substantially reduced.