Classifications

• • 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
• • 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
  • B05B7/1606—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 spraying of the material involving the use of an atomising fluid, e.g. air
  • B05B7/1613—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 spraying of the material involving the use of an atomising fluid, e.g. air comprising means for heating the atomising fluid before mixing with the material to be sprayed

Definitions

• the invention relates to a method for coating substrate materials thermal spraying, wherein the gas or gas mixture from at least one gas pressure vessel into a gas buffer container and from this gas buffer container to one Device for mixing a powdered filler material with the gas or gas mixture is passed, wherein the gas or gas mixture is heated and wherein the filler material by means of the gas or gas mixture on the to be coated Surface of the substrate material is passed.
• the invention relates also a device for coating substrate materials by thermal Syringes, the device at least one gas pressure container, at least a gas buffer container, a device for mixing a powder Filler material with the gas or gas mixture and a device for heating of the gas or gas mixture, and lines for the gas or gas mixture the gas pressure container into the gas buffer container and from this gas buffer container to the device for mixing the powdered filler material with the Includes gas or gas mixture.
• Thermal spraying for coating is known as autogenous as process variants Flame spraying or high-speed flame spraying, arc spraying, plasma spraying, detonation spraying and laser spraying.
• Thermal spray processes are essentially characterized in that they enable evenly applied coatings.
• Coatings can be applied by varying the spray materials can be adapted to different requirements.
• the spray materials can be processed in the form of wires, rods or as powder. With thermal In addition, thermal post-treatment can be provided for spraying.
• the gas or gas mixture with the aid of which the filler material is applied to the material to be coated Surface of the substrate material is usually conducted in one or more gas pressure vessels, for example one or more gas tanks, stored under high pressure.
• gas pressure vessels for example one or more gas tanks
• the liquefied gas is converted into the gaseous state. Furthermore a pressure increase is required.
• air and / or helium are also suitable for the powdered filler gas carrying a nitrogen, argon, neon, krypton, Xenon, oxygen, a gas containing hydrogen, a carbon-containing gas, in particular carbon dioxide, or mixtures of the aforementioned gases and Mixtures of these gases with helium.
• the proportion of helium in the total gas can be up to 90% by volume.
• a helium content of 10 to 50% by volume is preferred Gas mixture observed.
• the layers produced in this way adhere very well to a wide variety of substrate materials, for example on metal, metal alloys, ceramics, glass, plastics and composite materials.
• the coatings are of high quality, have an extraordinary low porosity and have extremely smooth spray surfaces, so that rework is usually not necessary.
• the gases mentioned have one sufficient density and speed of sound to meet the required high To be able to ensure speeds of the powder particles.
• the gas can contain inert and / or reactive gases. With the gases mentioned is the manufacture of very dense and particularly uniform coatings possible, which also characterized by their hardness and strength.
• the layers point extremely low oxide levels.
• substrate is not heated by a flame or a plasma, so none or only extremely minor changes to the base body and also no distortion of Workpieces occur due to thermal stresses due to thermal spraying.
• the gas or gas mixture be buffered. It is conceivable that the hot gas generation directly in the Buffer tank, i.e. the gas or gas mixture stored for buffering to heat in the buffer tank. This seems advantageous because in this case with With the help of a control unit, the desired pressure and temperature can be easily achieved for the gas jet carrying the powdered filler material can.
• the present invention is based on the object of the method mentioned at the outset and to further develop the device, in particular the efficiency and the Increase flexibility.
• the task is solved for the method in that the gas or Gas mixture is heated after leaving the gas buffer container.
• the object is achieved for the device in that the device for heating the gas or gas mixture in the flow direction after the Gas buffer container is arranged.
• the advantage of the invention is that on the one hand only the gas and directly required not the entire amount of buffered gas is heated and thus the hot gas generation becomes more efficient, easier to set and cheaper.
• the energy efficiency can further and also the flexibility increase.
• the gas line must between the buffer container and the device for mixing the powder Filler material with the gas or gas mixture are thermally insulated and / or the heat loss in this line when heating the gas or gas mixture be taken into account.
• thermal insulation leads to thick relatively stiff and little or not flexible cables. These restrict the Flexibility and reduce or prevent the mobility of the device for Mixing the powdered filler material with the gas or gas mixture.
• the device for mixing the powdered Filler material with the gas or gas mixture for example a Spray gun, can also be carried out by hand if necessary.
• the hot gas can be generated by means of an electrical resistance heater. This has the advantage of easy-to-use and inexpensive heating.
• the gas or gas mixture can also be by means of a flame burner or a plasma torch. These options are usually energetic very cheap. Inductive heating can also be used (Induction heating) can be provided for heating the gas or gas mixture.
• the gas jet can reach a temperature in the range between 30 and 1000 ° C, preferably heated between 100 and 800 ° C, all known powdered spray materials can be used, for example spray powder made of metals, metal alloys, hard materials, ceramics and / or plastics.
• a gas jet with a Pressure of 5 to 50 bar can be used.
• gas pressures in the range of 21 are particularly suitable up to 50 bar.
• Excellent spray results were achieved, for example, with gas pressures of about 35 bar.
• the high pressure gas supply can for example by method described in the own German patent application DE 197 16 414.5 or the gas supply system described there can be ensured.
• the powder particles can advantageously at a speed of 300 to 1600 m / s can be accelerated.
• Speeds are particularly suitable the powder particles between 1000 and 1600 m / s, particularly preferred between 1250 and 1600 m / s, because in this case the energy transfer in the form of kinetic energy is particularly high.
• the powders used in the process according to the invention preferably have Particle sizes from 1 to 100 ⁇ m.
• the invention also offers the possibility in connection with automation and with computer-controlled movement of the substrate or the device for Mixing the powdered filler material with the gas or gas mixture or the spray gun the thermal spray process particularly quickly and to perform inexpensively.

Landscapes

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

Applications Claiming Priority (2)

Publications (2)

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Family Applications (1)

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Cited By (7)

Families Citing this family (4)

Citations (5)

• 1997
  • 1997-12-18 DE DE19756594A patent/DE19756594A1/de not_active Withdrawn
• 1998
  • 1998-12-11 DE DE59810950T patent/DE59810950D1/de not_active Expired - Lifetime
  • 1998-12-11 EP EP98123464A patent/EP0924315B1/fr not_active Expired - Lifetime

Patent Citations (5)

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