Fistular cathodic axial powder feeding plasma painting gun

Abstract

The present invention relates to one kind of axially powder-feeding plasma spray gun for improved plasma spraying technological process. The spray gun consists of water-cooled hollow cathode and tubular anode. The sprayed powder material is fed through the hollow cathode and heated in the high temperature area inside the spray gun to reach melt state gradually before leaving from the spray gun and being sprayed at high speed to the surface of the workpiece to be sprayed to form plasma coating with specific performance.

Description

technical field [0001] The invention relates to a plasma spraying gun, in particular to an axial powder feeding type plasma spraying gun. Background technique [0002] Plasma spraying is the use of electric energy to convert gases such as argon, nitrogen and hydrogen into high-temperature plasma jets, heat and accelerate powders such as metals, metal oxides and ceramics to be sprayed, and then spray them onto the workpiece. [0003] A common plasma spray gun has a rod-shaped cathode and a tubular anode, and the powder material to be sprayed is sent into the plasma jet from the radial direction at the outlet of the spray gun, see "Plasma Spraying of Metallic and Ceramic Materials", New York, 1989. The disadvantage of this spray gun is that: since the powder is sent into the plasma jet outside the nozzle, the high-temperature area of ​​the plasma is not fully utilized, and after the high-temperature plasma gas is sprayed from the nozzle, it is affected by the mixing of extern...

AI Technical Summary

Problems solved by technology

The disadvantage of this spray gun is that: since the powder is sent into the plasma jet outside the nozzle, the high-temperature area of ​​the plasma is not fully utilized, and after the high-temperature plasma gas is sprayed from the nozzle, it is affected by the mixing of external air. At the same time, due to the dispersion of the particle size of the powder material, large particles can easily pass through the plasma jet, while small particles are not easy to enter the plasma jet, so the heating effect of the powder material is poor, and the energy utilization rate is very low. Low

This multi-cathode axial powder-feeding plasma spray gun has obvious improvements in improving energy utilization and coating quality, but it is obvious that it has disadvantages such as complex structure, difficult processing, and high cost, and requires three sets of power supplies Three cathode devices are supplied separately, which is inconvenient to operate and maintain

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