Laser-assisted cold spray coating method and nozzle apparatus

Abstract

The present invention discloses a laser-assisted cold spray coating method and a nozzle apparatus. According to the nozzle apparatus, one side of the nozzle throat portion is a nozzle constriction section, the other side of the nozzle throat portion is a nozzle expansion section, the nozzle side on the nozzle constriction section is provided with a high pressure gas inlet and a light transmittance window for entering of a laser beam, the light transmittance window deviates from the axis line of the nozzle, the nozzle on the nozzle constriction section is provided with a reflecting mirror A, the nozzle side on the nozzle expansion section is provided with a powder inlet, a reflecting mirror B, a reflecting mirror C and a reflecting mirror D, a laser beam entering from the light transmittance window sequentially passes through the reflecting mirror A, the reflecting mirror D, the reflecting mirror B and the reflecting mirror C in the nozzle and then is emitted from the nozzle expansion section, and the powder inlet is positioned between the reflecting mirror D and the reflecting mirror B; and according to the technical scheme, the laser is incident onto the reflecting mirror in the nozzle in a certain angle forming with the nozzle axis line, and the light beam is subjected to multiple reflections through the reflecting mirrors on the inner wall of the nozzle and finally irradiates on the substrate, such that the gas, the powder and the substrate inside the nozzle can be uniformly pre-heated.

Description

technical field [0001] The invention relates to a laser-assisted cold spraying method and a nozzle device, in particular to a supersonic nozzle device for laser cold spraying. Background technique [0002] Cold spraying, also known as cold gas dynamic spraying (Cold Gas Dynamic Spray, CGDS), was proposed by former Soviet scientists in the middle and late 1980s. It is a spraying technology based on the principle of aerodynamics. The principle is to use high pressure The gas (nitrogen, helium, air, or mixed gas, etc.) carries the powder particles into the high-speed airflow, and the supersonic gas-solid two-phase flow is generated through the zoom tube (Laval tube), and the powder particles are accelerated by the supersonic nozzle in a solid state. It collides with the substrate at a very high speed, and deposits on the surface of the substrate to form a coating by generating strong plastic deformation. Unlike thermal spray, which relies on thermal or chemical energy, cold sp...

AI Technical Summary

Problems solved by technology

However, when the laser spot is irradiated sideways, only the substrate is preheated. For some hard particles, the carrier gas still needs to be preheated in the nozzle to make the powder finally deposit on the substrate, and the disadvantages of large gas consumption have not been resolved.

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