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
  • B05B7/20—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 by flame or combustion
  • B05B7/201—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 by flame or combustion downstream of the nozzle
  • B05B7/203—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 by flame or combustion downstream of the nozzle the material to be sprayed 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
  • C23C4/129—Flame spraying

Definitions

• the present invention relates to methods of forming a deposit by projection, by means of a fusion and projection gun, of a filler material on a substrate, of the type comprising the steps of melting the material with a flame. of filler continuously conveyed in the form of a wire or rod and of projecting onto the substrate the filler material melted by a flow of carrier gas.
• the flame projection of a filler material makes it possible to increase the properties of the substrate by the production on it of a protective surface coating having specific characteristics, in particular of resistance to corrosion and to wear.
• the filler material is heated by a flame, typically oxycombustible, melting a film of the material which is atomized by the carrier gas, the particles thus formed being accelerated and coming to crash onto the substrate to be coated.
• the two most important criteria are, for equivalent quality of deposition: the yield (ratio between the weight of filler material actually deposited on the substrate and the weight of filler material actually consumed) and the deposition rate (in kg per hour) (product of the yield by the weight of filler material actually consumed per unit of time).
• This last parameter if it depends directly on the value of the yield, is also a function of the speed of advance of the wire of filler material.
• the latter for a given quality of deposit, depends mainly on the power of the flame which is generally limited by the geometry of the heating nozzle of the spray gun.
• the object of the present invention is to propose an improved method making it possible to increase significantly, and with increased safety, the feed rates of the filler material wire and therefore, - with conventional materials, to increase notably, equivalent returns, the deposit rate.
• the method comprises the step of preheating in a controlled manner the filler material before its introduction into the gun.
• the filler material being typically metallic
• the filler material wire is preheated to a temperature between 100 and 650 ⁇ C, approximately, typically between 300 and 600 e C, the heating preferably carried out for oxidizable filler materials, under a controlled, typically inert, atmosphere.
• the present invention also relates to a device for implementing the method, comprising a spray gun comprising a passage channel for the wire of filler material, and a wire reel, further comprising, on the path of the wire from the reel, a heating station traversed by the wire and comprising means for heating the wire, advantageously associated with means for regulating the temperature and a controlled atmosphere in the heating station.
• the single figure is a schematic view of a device for implementing the method according to the invention.
• a flame spray gun 1 comprising a channel 2 for passing and guiding a wire or a flexible rod 3 of filler material to be projected through the central ent in a nozzle-shaped end of the gun into which open, concentrically around the central outlet of the channel 2, angular conduits 4 distributed ejection of flammable oxycombustible mixture and a peripheral crown 5 of ejection of a carrier gas.
• the conduits 4 are connected, by a pipe 6, to. a source 7 of combustible gas, for example a propylene and methylacetylene compound sold under the name "TETRENE” or an ethylene and acetylene compound sold under the name "CRYLENE".
• the ring 5 is connected, by a pipe 8, to a source 9 of carrier gas under pressure, for example compressed air or nitrogen under pressure.
• the gun 1 comprises means 10 for selectively driving the wire 3, which is generally available from a reel or a reel 11.
• the preheating station 12 is in the form of an insulated chamber crossed by the wire 3 and containing heating means, advantageously electric for better temperature control and for exploiting the power source.
• electrical already available for the gun typically electrical resistors, or tubes, infrared or induction coils supplied by an electrical generator 13 via a control block 14 coupled to a temperature sensor in the chamber (not shown) so as to bring the temperature of the wire 3 at the outlet of the enclosure to a temperature higher than 100 ° C., typically higher than 300 "C., depending on the type of filler material.
• the preheating station can be coupled gun 1, immediately upstream from channel 2.
• the wire speeds conventionally obtained are of the order of 40 cm / minute, or a deposition rate of approximately 1.4 kg / hour .
• the speed of movement of the wire can be brought to more than 50 cm / minute, ie a deposition rate greater than 1.8 kg / hour for an equivalent yield, of the order of 75%.
• a chamber is created and maintained in inert atmosphere by connecting the latter, via a control valve 15, to a source 16 of inert gas under pressure, typically nitrogen, argon or a mixture of these two gases.

Landscapes

• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Plasma & Fusion (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Physics & Mathematics (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Combustion & Propulsion (AREA)
• Coating By Spraying Or Casting (AREA)
• Application Of Or Painting With Fluid Materials (AREA)
• Physical Vapour Deposition (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=9417095

Family Applications (1)

Country Status (3)

Families Citing this family (7)

Family Cites Families (2)

• 1991
  • 1991-09-19 FR FR9111545A patent/FR2681538B1/fr not_active Expired - Fee Related
• 1992
  • 1992-09-18 EP EP92920780A patent/EP0560964A1/de not_active Withdrawn
  • 1992-09-18 WO PCT/FR1992/000875 patent/WO1993006256A1/fr not_active Application Discontinuation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events