PLASMA SPRAYING METHOD OF WEAR-RESISTANT COATING WITH THICKNESS MORE THAN 2 mm Russian patent published in 2018 - IPC C23C4/12 C23C24/08 C23C28/00 

FIELD: instrument engineering.

SUBSTANCE: invention relates to a method for plasma spraying of wear-resistant powder coatings on parts of various mechanisms, used in mechanical engineering, metallurgy, power engineering, aviation, shipbuilding, defense industry and other spheres of production. Method includes pre-blasting and degreasing of the sprayed surface. First, a coating layer with a thickness of no more than 0.2 mm is sprayed with a high-speed turbulent flow regime of the plasma jet with a plasma-forming gas consumption of 2.8–3 g/s and with the location of the plasma torch at the initial distance from the deposited surface. Stop feeding the powder and reduce the initial distance of the plasma torch from the sprayed surface. After this, the surface is heated at a low-speed laminar flow-out regime of a plasma jet with a plasma-forming gas consumption of 0.7–0.9 g/s to a temperature (0.2–0.3) T_mel, where T_mel – the melting point of the coating material. Plasma torch is set at the initial sputtering distance from the sprayed surface and the main coating layer is sprayed to a predetermined thickness at a high-speed turbulent flow regime of a plasma jet with a plasma-forming gas flow rate of 2.8–3 g/s.

EFFECT: technical result consists in the formation of a wear-resistant coating with a thickness of more than 2 mm with a minimum level of residual stresses that are substantially lower than the adhesion strength of coatings.

1 cl, 4 dwg, 2 ex