PLASMA SPRAYING METHOD Russian patent published in 2023 - IPC C23C4/134 C23C4/08 C23C24/04 C23C30/00 

FIELD: coatings.

SUBSTANCE: method for obtaining a wear-resistant coating by plasma spraying. Preliminary treatment and degreasing of the surface of the workpiece are carried out, coating is applied by layer-by-layer deposition of powdered material with the main plasma-forming gas using a plasma torch, and then the supply of powdered material is stopped. Compressed air is used as the main plasma gas. As a powder material, self-fluxing powder “ПР-НХ17СР4” with a mass fraction of 23%, powder “ПГ-ФБХ6-2” with a mass fraction of 73% and aluminium powder with a mass fraction of 4% are used. In the process of spraying powdered material, additional plasma-forming gas in the form of hydrocarbons is fed through the plasma torch. The mentioned layer-by-layer spraying is carried out at the current of the arc of the plasma torch - 170-175 A, voltage - 165-170 V, flow rate of the said plasma gases - 2.5-2.7 m³/h, at a pressure of 0.2 MPa, flow rate of the sprayed powder - 10 g/s, spraying distance - 140-160 mm and the speed of movement of the plasma torch - 40 cm/min. After stopping the supply of powdered material, plasma melting of the sprayed powdered material is carried out at a plasma torch arc current of 190-200 A, a main plasma gas flow rate of 2.5-2.7 m³/h, at a pressure of 0.2 MPa and a flashing distance of 40-60 mm. The plasma torch is delayed in the area of the sprayed powder material for heating until melting, after which the plasma torch is moved at a speed of 15-18 cm/min to another area of the sprayed powder coating material.

EFFECT: improved quality of the resulting coating characterized by increased values of hardness and wear resistance.

1 cl, 1 dwg, 3 tbl