Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
  • B05B7/18—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed the material having originally the shape of a wire, rod or the like
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B7/00—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas
  • B05B7/16—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed
  • B05B7/22—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed electrically, magnetically or electromagnetically, e.g. by arc
  • B05B7/222—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed electrically, magnetically or electromagnetically, e.g. by arc using an arc
  • B05B7/224—Spraying apparatus for discharge of liquids or other fluent materials from two or more sources, e.g. of liquid and air, of powder and gas incorporating means for heating or cooling the material to be sprayed electrically, magnetically or electromagnetically, e.g. by arc using an arc the material having originally the shape of a wire, rod or the like
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
  • C23C4/131—Wire arc spraying
• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C4/00—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge
  • C23C4/12—Coating by spraying the coating material in the molten state, e.g. by flame, plasma or electric discharge characterised by the method of spraying
  • C23C4/134—Plasma spraying
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05H—PLASMA TECHNIQUE; PRODUCTION OF ACCELERATED ELECTRICALLY-CHARGED PARTICLES OR OF NEUTRONS; PRODUCTION OR ACCELERATION OF NEUTRAL MOLECULAR OR ATOMIC BEAMS
  • H05H1/00—Generating plasma; Handling plasma
  • H05H1/24—Generating plasma
  • H05H1/48—Generating plasma using an arc
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05B—SPRAYING APPARATUS; ATOMISING APPARATUS; NOZZLES
  • B05B13/00—Machines or plants for applying liquids or other fluent materials to surfaces of objects or other work by spraying, not covered by groups B05B1/00 - B05B11/00
  • B05B13/06—Machines or plants for applying liquids or other fluent materials to surfaces of objects or other work by spraying, not covered by groups B05B1/00 - B05B11/00 specially designed for treating the inside of hollow bodies
  • B05B13/0627—Arrangements of nozzles or spray heads specially adapted for treating the inside of hollow bodies
  • B05B13/0636—Arrangements of nozzles or spray heads specially adapted for treating the inside of hollow bodies by means of rotatable spray heads or nozzles

Definitions

• the invention relates to a device for thermal coating of a surface according to the preamble of claim 1 and to a method carried out thereby and a component produced by the method.
• Devices according to the invention for thermally coating a surface are described in US Pat. No. 6,372,298 B1, US Pat. No. 6,706,993 B1 and WO 2010/1 12567 A1. All apparatus include: a wire feeder for feeding a wire, the wire acting as a first electrode; a source of plasma gas for generating a plasma gas stream; a nozzle body having a nozzle opening through which the plasma gas stream is passed as a plasma jet to a wire end; and a second electrode disposed in the plasma gas stream before entering the nozzle orifice.
• This arc also forms the plasma gas flowing through the nozzle opening.
• the plasma jet emerging from the nozzle opening impinges on the end of the wire and there causes a melting of the wire with the arc and the removal of the molten wire material in the direction of the surface to be coated.
• Secondary air nozzles are mounted annularly around the nozzle opening, creating a fluidized secondary gas jet which strikes the wire-end-melted material behind the wire end to accelerate transport toward the surface to be coated and secondary atomization of the molten wire material.
• the coating should be produced without major inclusions of non or only partially melted spray particles. Such inclusions or so-called scratches are usually caused by not completely molten wire material. It has been found that if the wire is to be melted as completely and uniformly as possible, exact positioning of the wire relative to the nozzle opening is necessary. Likewise, a very short operating time of the device in the coating operation can make a new adjustment of the wire position necessary.
• the object of the invention is therefore to provide an improved device with which a safe and good coating of the surface, in particular a coating without inclusions and splashes, can be produced in a simple manner.
• the wire feeder is adjustable, whereby the wire end located in front of the nozzle opening can be moved by a certain displacement, an adjustment of the wire or the wire end can be made relative to the nozzle opening in a simple manner. Under the adjustability or adjustment of the wire is a very small adjustment to understand.
• adjustment paths of less than 0.2 mm are usually necessary in order to achieve sufficient accurate positioning.
• the adjustment is not greater than 0.08 mm.
• the wire feeder can, of course, due to the design, also move the wire end to larger adjustment paths. However, this is not necessary for the exact position of the wire end, but at best to be able to determine the optimal position during the adjustment process by a larger adjustment is driven and then the optimal wire position is determined iteratively.
• an adjustment of the adjustment is at least partially transverse to the wire longitudinal axis and / or at least partially transverse to the plasma jet.
• the wire feed direction can be designed so that an adjustment takes place in any direction. At least one component of the adjustment is transverse to the wire axis. Another component of the adjustment is transverse to the plasma jet. In this way, the adjustment of the wire end results in any case in a lateral displacement relative to the plasma jet. In this case, the nozzle longitudinal axis of the nozzle opening approximately in the same direction as the plasma jet.
• the wire feeder is adjustable by means of static adjustment.
• Static means that the setting is not changed during one or more coating operations.
• the setting is made when the device is switched off.
• the wire can be positioned in a simple manner in front of the nozzle opening or in the plasma jet.
• Particularly suitable are adjusting screws, by means of which the exact position of the wire can be adjusted quite accurately.
• the wire feed device is adjustable by means of dynamic adjustment means.
• This also allows an adjustment during operation of the device, including during a coating process.
• the adjustment can be quasi-static, so there is a continuous, but slight adjustment instead of the wire is always in the correct position. But it can also be done a dynamic adjustment by the adjustment takes place with a certain frequency.
• a rotatable device as z. B. is used for the coating of inner holes
• the frequency may be adjusted to the speed of the device to compensate for a slight curvature of the rotating relative to the device wire.
• the frequency can also be higher than the speed. Or the frequency is such that a slight swinging of the wire end in the higher frequency range, eg. B.
• Piezo crystals which are reliable and fast with little power, i. E. high frequency, can be switched.
• piezo stacks In order to achieve the required adjustment paths are possibly so-called piezo stacks, so to use several stacked piezocrystals.
• the wire feed device has an adjustable guide piece on which the adjustment means act.
• An adjustment of the guide piece allows the exact alignment of the wire.
• This guide piece is expediently arranged shortly before the exit of the wire from the wire feed direction.
• the wire feeding on an adjustable guide tube and a fixed attachment piece wherein the guide tube connecting piece and guide piece connects.
• the wire feeding device can be fixed in the device, and by means of the guide tube, the wire is guided to the guide piece.
• This provides a relatively long guide of the wire before it exits the leader.
• guide tube, attachment piece and guide piece on a continuous bore, through which the wire is guided.
• the leadership of the Wire in the wire feeder can also be done by other suitable means.
• the attachment piece and guide tube are made in one piece and the guide tube is elastically deformed during adjustment. Due to the small adjustment paths, the elastic deformation of the guide tube may be sufficient to position the wire.
• the guide piece can be firmly connected to the guide tube here. Or the guide piece is a separate part, the guide tube then takes over only the supply of the wire to the guide piece. The separate guide tube and guide piece can be centered over the wire itself.
• attachment piece and guide tube are made in two parts and between the attachment piece and guide tube, an elastic element is arranged, in particular an O-ring. While the attachment piece is firmly anchored in the device, the guide tube may be supported by the elastic element. At the same time allows the elastic support a small deflection of the guide tube to accomplish the adjustment of the wire end.
• the guide piece may be firmly connected to the guide tube or be designed as a separate part. Again, the wire takes over the centering of the individual parts to each other, at least of attachment piece and guide tube, and if the guide piece is also separate, of guide piece and guide tube.
• the guide piece has lateral guide surfaces for guiding in the device transversely to the adjustment direction. Since the adjustment direction is essentially transverse to the plasma jet, the positioning in the direction of the plasma jet is sufficient by means of the guide surfaces.
• the dynamic / and or static adjustment during the starting process of the method may be different than during the actual coating process.
• the wire position or the Dynamic adjusting movement can be well adapted to the requirements of an optimal wire melt. This includes z. B. that at the start of the process, a position of the wire is different than during coating, and that when starting the process, a dynamic adjustment is different than during coating, both with respect to the adjustment and the frequency of the adjustment.
• the small, adjustable wire feeder can be easily accommodated in a dimensionally limited device. Limited because a device that is to be able to enter a cylinder bore can only have a certain dimensions, usually not more than 4 to 5 cm in diameter.
• Figure 1 shows a longitudinal section along the wire and transversely to the nozzle opening by an inventive device.
• Figure 2 is a longitudinal section along the wire and along the nozzle opening by the inventive device of Fig. 1.
• FIG. 3 shows only the wire feed device from FIG. 1;
• FIG. and FIG. 4 shows only the wire feed device from FIG. 2.
• FIGS. 1 and 2 show sections through an inventive device 1.
• the device 1 has a nozzle body 2 with a nozzle opening 3 and a wire feed device 4 for feeding a wire 5.
• 1 shows the longitudinal section along the wire 5 and transversely to the nozzle opening 3
• Figure 2 shows the longitudinal section along the wire 5 and along the nozzle opening 3.
• the wire 5 is connected via an electrical contact, not shown
• Wire feeder 4 is arranged, connected to a power source and thus acts as a first electrode.
• a plasma gas feed 6 designed as a cavity, which is connected to a source of plasma gas (not shown).
• a second electrode 7 is arranged, which is also connected to the power source.
• gas flows from the plasma gas feed 6 through the nozzle opening 3 onto the wire end 8 of the wire 5.
• the current source supplies a corresponding voltage and current, an arc forms between the wire end 8 and the second electrode 7 through the nozzle opening 5 , whereby the gas flowing through the nozzle opening 5 ionizes and thus becomes the plasma gas.
• the plasma jet emerging from the nozzle opening 3 impinges on the wire end 8 and causes there with the arc a melting of the wire 5 and the removal of the molten wire material in the direction of the surface to be coated.
• the wire 5 must be constantly promoted in the direction of feed V to compensate for the melting of the wire end 8.
• Secondary air nozzles 9 are mounted in annular fashion around the nozzle opening 3 and produce a fluidized secondary gas jet which atomises the molten material at the wire end 8 towards the melt area, thus accelerating transport towards the surface to be coated and finer distribution of the molten wire material ,
• the wire feed 4 is shown. It consists of an adjustable guide piece 1 1, an adjustable guide tube 12 and a fastened in the device 1 attachment piece 13, wherein the guide tube 12 attachment piece 13 and guide piece 1 1 connects.
• This guide of the wire 5 in turn centers the three parts against each other.
• the guide piece 1 1 has lateral guide surfaces 14 for guiding in the device 1 transversely to the adjustment directions F. At the bottom, the guide piece 1 1 lower support surfaces 15 which cause a guide of the guide piece 1 1 in the direction of the wire longitudinal axis. Thus, the guide piece can be performed in the device 1, that only a shift in the adjustment directions F is possible.
• the adjustment S is shown by the dashed line of the guide piece 1 to the left and right. At least at its lower end, the guide tube 12 moves accordingly, while it is rather immovable in the upper region, at the transition to the attachment piece 13.
• an O-ring 16 is arranged between attachment piece 13 and guide tube 12, between attachment piece 13 and guide tube 12, an O-ring 16 is arranged.
• the attachment piece 13 is firmly screwed into the device 1 and presses the O-ring 16 against the guide tube 12, which in turn presses the guide piece 1 1 on the support surfaces 15 against the device 1.
• guide piece 1 1, guide tube 12 and attachment piece 13th braced against each other and clearly positioned in the device - except for the degree of freedom of the adjustment directions F - wherein the tension depends on the degree of deformation of the O-ring 16.
• the bias of the O-ring 16 still has the task of allowing the adjustment of the guide piece 1 1, a rotation of the guide tube 12 relative to the attachment piece 13 by its elastic deformation.
• the wire feeder 4 is connected to the wire 5 as the first electrode.
• the housing 18 of the device 1 is electrically connected to the second electrode 7.
• the insulation of the wire feeder 4 relative to the housing 18 is carried out by the wire feeder 4 is fixed in the insulating block 20, wherein the insulating block 20 is made of a non-conductive plastic.
• the insulating pieces 19 are therefore necessary so that via the grub screws 17 no electrical contact between the housing 18 and wire feed 4 is made.
• the insulating pieces 19 may also be designed as piezoelectric actuators. Then either a static voltage and thus a static adjustment can be applied to create a low clearance compensation. Or an AC voltage can be applied which causes a dynamic adjustment of the position of the wire 5.
• the dynamic adjustment takes place with a frequency not less than 50 Hz. Particularly advantageous is an adjustment frequency of 1 kHz or greater. In any event, these frequencies are significantly higher than the speed of the device 1 as it rotates about the fixed wire 5 to produce the coating in a bore.
• the speed of the device 1 is usually a function of the bore diameter to be coated in a range of 100 - 700 U / min, ie at a frequency of 1 - 12 Hz.
• adjustment frequency is significantly higher and the fixed wire 5 to which the Device turns 1, is applied from all sides with the necessary adjustment of the plasma jet.
• the dynamic adjustment can also be combined with a static adjustment. Furthermore, during the starting process of the method, the dynamic / and or static adjustment may be different than during the actual coating process. This can be a variety of tolerances at the beginning and / or during the coating compensate.

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• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Electromagnetism (AREA)
• Nozzles (AREA)
• Plasma Technology (AREA)
• Coating By Spraying Or Casting (AREA)

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• 2011
  • 2011-01-11 DE DE102011002501A patent/DE102011002501A1/en not_active Ceased
• 2012
  • 2012-01-06 WO PCT/EP2012/050192 patent/WO2012095371A1/en not_active Ceased
  • 2012-01-06 EP EP12701688.9A patent/EP2663406B1/en active Active
  • 2012-01-06 CN CN201280004725.7A patent/CN103379965B/en active Active
  • 2012-01-06 US US13/978,856 patent/US9056326B2/en active Active

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