Does plasma spraying belong to thermal spraying?

Plasma spraying technology is a thermal spraying technology developed in the 1970s. Plasma spraying technology is more efficient than traditional high-pressure oxygen fuel spraying and arc spraying technologies. Plasma spraying has good adhesion and compact structure, variable thickness, and low thermal strain, making it particularly suitable for the formation of amorphous coatings.

The technical principle is to use combustion or discharge to heat the raw material particles to a molten or semi molten state, and then use flames to assist in the flow of fat or compressed air spraying onto the substrate, leveling and nationalizing the particles into accumulated fragments, forming a coating. Thermal spray coatings have functional characteristics such as wear resistance, friction reduction, thermal insulation, insulation, high temperature resistance, oxidation resistance, and microwave radiation resistance. They have the advantage of reducing the size of parts caused by wear and corrosion, saving materials and energy, and are widely used in aerospace, automotive, shipbuilding, petrochemical and other fields.

In plasma spraying, two important components can be seen: a nozzle that sprays sufficient plasma heat, and a powder particle sprayer. This will soften and coat the porcelain and metal materials. The characteristics of plasma flow are controlled by the negative electrode nozzle, gas type, gas pressure, gas mixture ratio, and electric arc power level. The coating powder is transported to the outlet of the plasma nozzle through a sprayer. When the particles arrive, they accelerate and heat up simultaneously, causing them to collide with high temperature and high kinetic energy, forming a thermal barrier layer on the surface.

When painting, pay attention to controlling and adjusting the heat and the painting distance from the parts. Distance too far can lead to waste, while distance too close can result in uneven melting and burnt black spots. So, after painting, it is usually necessary to check. Check if there are particles on the surface of the first floor and if the sprayed surface color is red. If there are no issues, proceed with the second spray painting; If there are any issues, repaint or manually remove the black spots.

To save time and improve work efficiency, it is generally necessary to place multiple components simultaneously on the workbench for painting. At the same time, monitoring personnel need to observe the operation of the production room through hot glass in the monitoring room. After spraying, it is necessary to clean and remove dust from the workshop.

As one of the key technologies in the field of materials science, thermal spraying technology is an important component of manufacturing technology. With the improvement of coating performance requirements and innovation of spraying technology, spraying technology has made new developments, such as supersonic spraying, plasma spraying, ceramic spraying, alumina spraying, tungsten carbide spraying wear-resistant pipelines, sandblasting and zinc spraying, etc.