Advantages of high-power plasma thermal spraying equipment for preparing ceramic coatings

       Introduction of high-power plasma thermal spraying equipment



Usually, we call the plasma thermal spraying system with an output power of more than 80KW as high-power plasma equipment. The domestic equipment with the word 80 is basically the equipment with this power, and some foreign equipment can reach 100KW or even higher. Such equipment is more common in Three-cathode or three-anode spray guns, some are five-anode spray guns (this development is just like the evolution of car gear boxes, from 4AT to 6AT, then 8, 9, 10AT, with each passing day. P.S. I prefer CVT gearboxes).

The spray gun with cascaded arc technology reduces the dependence on gas and gas flow, the plasma flame flow is more stable, the raw material powder is heated more uniformly, and there is no or little process drift.

At the same time, since the plasma arc of this spray gun is elongated, high-power thermal spraying at low current and high voltage can be achieved. This working mode is of great help to prolong the service life of the anode and cathode of the spray gun in the thermal spraying system.



Advantages of preparing ceramic coatings



Take the metal oxide coating in the ceramic coating as an example: since the ceramic coating is mostly built on the metal substrate, and the crystal structure, expansion coefficient and physical properties of the former are very different from those of the latter, it is necessary to bond coating to eliminate the internal stress between the coatings, make the thermal expansion coefficient convergent, and increase the bonding strength between the surface layer and the substrate.

In the preparation of chromium oxide ceramic coatings, a common base layer is a nickel-chromium alloy coating. Orthogonal experiment method is generally used to determine spraying parameters (current, voltage, spraying distance and powder feeding amount). This official account has introduced the measurement methods of bonding strength and deposition efficiency in previous articles, you can click on the bold words to follow up. For the reference spraying parameters of powder on thermal spraying equipment, you can ask our sales representative to receive you.

In general, the process stability and efficiency of high-power plasma thermal spraying equipment in the preparation of ceramic coatings are worth looking forward to, and its use cost also has a comparative advantage.



Post-treatment of ceramic coating



The porosity problem of ceramic coatings is usually solved by sealing (also achieved by laser cladding modification). The surface layer is penetrated, sealed and cured to further play the role of corrosion resistance and insulation. After the sealing process, the coating is transparent and can still be machined.