SU1727923A1 - Device for electric arc application of metal coating - Google Patents

Abstract

Usage: the invention relates to devices for spraying materials and can be used to improve the quality of coatings and the performance of the process when applying coatings by arc metallization. SUMMARY OF THE INVENTION: The device includes two coaxially mounted electrodes and two nozzles for supplying compressed air located in a vertical plane perpendicular to the plane of the electrodes; acoustic oscillators with reflectors are installed at the ends of the nozzles, the axis of the generators located in a vertical plane perpendicular to the plane of the electrodes . 1 il.

Description

The invention relates to a device for spraying materials and can be used when applying coatings by arc metallization.

A device for electric arc metallization is known, comprising a housing, two nozzles installed therein for supplying compressed air and two coaxially mounted electrodes.

The disadvantage of this device is the formation during its operation of a wide range of sprayed particles, which causes the formation of coatings with increased roughness and porosity with significant losses of sprayed material and low process performance.

The purpose of the invention is to improve the quality of the coating and the performance of the process.

The goal is achieved by those. that at the ends of compressed air nozzles, acoustic oscillators with reflectors are installed, the generator axis being located in a vertical plane perpendicular to the plane of the electrodes of the device for electric arc metallization.

The drawing shows a device for arc metallization, a cut.

The device for arc metallization consists of two electrodes 1 and two nozzles 2 for supplying compressed air to the inside of the nozzle 3. Above the nozzle outlet, acoustic oscillators are installed, consisting of a rack 4 with internal mutually perpendicular channels, the inlet tube 5 and the nozzle 6, as well as axis 7 and resonator 8 common to two generators. Racks 4 strengthened reflectors 9, which provide the effect of acoustic oscillations on the melting and sputtering zone of metal wires 10

The device works as follows.

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After switching on the voltage and supplying compressed air and wires, the following processes occur. The compressed air, the exit from the nozzle 2 and the passage through the inlet tube 5, expire from the nozzle of the generator 6. Facing the resonator 8 in its path, the air flow generates acoustic oscillations. By adjusting the gap between the compressed air supply nozzle and the generator inlet tube, the pressure of the air flow at the outlet of the generator nozzles is changed. By changing the angle of inclination of the plane of the reflector JLK of the grid of electrodes 1, a maximum of cell pressure is located in the region of the center of the electric arc.

In the process of coating by arc metallization, the ends of the sprayed wire, moving along the current collecting plates, are brought closer together by a distance sufficient to form an electric arc. A jet of compressed air blows off a layer of molten liquid material formed at the ends of the wires and sprays it to form particles that form the coating.

When acoustic oscillations are communicated to compressed air, shock waves are applied to the surface of a thin film of the melt formed as a result of the melting of the wires. Micro-streams formed in this case in the melt layer intensify the heat exchange processes between the surface and the boundary of the liquid metal-wire. As a result, the overheating of the melt surface decreases and, consequently, the viscosity gradient decreases over the layer thickness, as well as the probability of formation of particles with a size of less than 5x10 m. Thus, the amount of oxides in the sprayed layer decreases, and the loss factor due to oxidation and evaporation decreases. small particles.

The impact of shock waves on the volume of liquid metal formed in the electric arc field causes its crushing and the formation of particles with a size smaller than without the use of acoustic oscillations. The reduction in the surface tension of the melt as a result of the impact of shock waves further reduces the size of the sprayed particles and accelerates the process of spraying the wires.

Claims (1)

Apparatus of the Invention A device for arc metallization comprising two coaxially mounted electrodes and two nozzles for supplying compressed air located in a vertical plane perpendicular to the plane of the electrodes, characterized in that, in order to improve the quality of the coating and the performance of the process, at the ends of the nozzles acoustic oscillators with reflectors were installed, the generator axis being located in a vertical plane perpendicular to the plane of the electrodes.