Abstract: The plasma gun head for plasma spraying apparatuses essentially comprises a cathode body mender, an anode body member and an insulating member inserted there between and electrically insulating these two members from each other. Inserted into the cathode body member is a cathode assembly, and into the anode body member an anode nozzle, both extending transverse to the longitudinal axis of the plasma gun head. The anode body member and the cathode body member both are provided with cooling channel sections which are connected in series as seen in the direction of flow of the cooling medium. The anode nozzle is rigidly integrated into the anode body member; thus, it is not necessary to provide sealing elements in this thermally highly stressed region. The sealing elements required for sealing the cooling channel sections are located remote from the anode nozzle and the cathode assembly, respectively, in a region, which is thermally not stressed.

Abstract: The plasma spray apparatus for the coating of the inner walls of bores and tubes essentially comprises a housing, a supply member, a plasma gun shaft member and a plasma gun head member. The plasma torch created in the head member escapes transversely with regard to the central longitudinal axis of the plasma spray apparatus. The supply member is rotatably received in the interior of the housing and is driven by an electric motor and a gear box. The supply member comprises a swiveling coupling member by means of which the plasma gun shaft member is connected to the shaft member. Thus, the rotatable shaft member can be radially deflected with reference to the axis of rotation. Thus, the head member fixed to the free end of the shaft member can be radially adjusted. With such a plasma spray apparatus, bores and tubes having greatly varying inner diameters can be reliably coated.

Abstract: The plasma gun assembly of the invention is particularly suitable for coating the inner surfaces of narrow cavities, bores, channels or the like. It essentially comprises a plasma gun head member, a plasma gun shaft member and a connector member. These three units are designed as replaceable modules which can be replaced by the operator of the plasma gun assembly quickly and easily. The plasma gun head member is connected to the plasma gun shaft member by means of only two screws, and the connector member is connected to the plasma gun shaft member by means of only three screws. All channels, conductors and conduits for supplying the media and the electric energy required for the operation of the plasma gun assembly are running in the interior of the plasma gun shaft assembly.

Abstract: The invention provides an apparatus for depositing particulate or powder-like material on the surface of a substrate. The apparatus comprises a hollow tube-like chamber consisting of a heat-resistant material, in which a plasma torch is generated. By means of a device for supplying solid particulate or powder-like material, the material is molten in the plasma torch and deposited on the surface of the substrate. In order to achieve a uniform temperature distribution in the plasma torch, the apparatus comprises at least two induction coils located at the outer surface of the hollow tube-like member and a high frequency generator means having at least two generator sections. A first of the at least two generator sections generates energy with a first higher frequency and a second of the at least two generator sections generates energy with a second lower frequency.

Abstract: The device for the dosed conveying of powder to a powder processing unit, particularly to a plasma spray device, comprises a volumetric dosing unit and a weighing unit which together allow a gravimetric powder dosing. The dosing unit includes: a rotatable dosing disc having a vertical axis of rotation; a drive unit mounted below said rotatable dosing disc; and powder feeding and withdrawal means mounted above said dosing disc. This dosing unit, having first and foremost a vertical extension, is fixed to a weighing platform which rests on a plurality of weighing cells. The drive unit is arranged below said weighing platform, in order to situate the center of gravity of said dosing unit at least approximately at the level of said weighing platform. This considerably reduces the liking of the dosing unit, as compared with a weighing platform arranged entirely above the dosing unit, thus allowing a gravimetric powder dosing with high accuracy and uniformity.

Abstract: In order to initiate the automatic regulation of the operating current of a current source in a power supply unit upon closing the operating load circuit connected to the current source, it is proposed that the current source is controlled by presetting the circuit parameters such that the current flowing in the operating load circuit upon closing the operating load circuit reaches a preset or desired value. The current regulation is brought into effect as soon as the difference between the effective value and the preset desired value of the current flowing in the operating load circuit falls below a predetermined threshold value. For this purpose, a regulation circuitry is provided, comprising a voltage regulator, a current regulator and a switching circuitry with a threshold value circuit. The switching circuitry generates a switching signal which effects the change from the initial voltage regulation to the subsequent current regulation as soon as the operating current exceeds a preset value.

Abstract: A method for forming an abradable composite material and the material so formed. A filler is fed axially into a stream of high-temperature combustion gases such that the filler is entrained in the gaseous stream. The gaseous stream containing the filler is then used to atomize the molten tip of a metal wire which is continuously fed into the gaseous stream. The resultant gaseous stream which contains both the filler and the atomized molten metal is directed to the surface of a target. The filler and the molten metal impact the target and combine to form a substantially continuous metal matrix in which the interstices are filled by the filler. The composite material abrades readily upon frictional contact with a moving part.

Abstract: A plasma spray apparatus for spraying powdery or gaseous material comprises an indirect plasmatron to create an elongated plasma torch. The plasmatron comprises at least one, preferably three cathode members, an annular anode member located distantly from the cathode members and a plasma channel extending from the cathode members to the anode member. The plasma channel is delimited by a plurality of annular neutrode members which are electrically insulated from each other. For axially feeding the powdery or gaseous material into the plasma torch a supply tube is provided which is located close to the cathode member at the beginning of the plasma channel. The plasma channel has a first zone with a reduced diameter located in that region of the plasma torch which is near to the cathode member and a second zone with increased diameter located between the first zone with a reduced diameter and the anode member.

Abstract: A method of forming a composite material by flame spraying. A composite thermal spray coating is formed by heating and accelerating a particulate material with a thermal spray gun and atomizing a molten metal to produce a combined, high-velocity stream containing both the heated particulate material and the atomized molten metal. The spray stream is directed to a substrate on which the composite coating is formed by a deposition of the materials.

Abstract: A thermal spray gun having an advanced, streamlined design which simplifies assembly of the gun components and reduces maintenance downtime. The thermal spray gun has a fuel/oxidant gas nozzle with a plurality of oxygen outlets arranged in a ring upon a discharge face. Three alternative fuel gas outlet configurations provide a combustion flame within a barrel having an inlet adjacent the fuel/oxidant gas nozzle discharge face. Powdered feedstock is supplied through a centrally disposed feedstock injector and is heated by the combustion flame. Oxidant gas, fuel gas and power feedstock are simultaneously discharged into the barrel, through a single plane perpendicular to the direction of gas and feedstock flow.