METHOD OF MAKING EROSION-RESISTANT HEAT-PROTECTIVE COATS Russian patent published in 2006 - IPC C23C4/00 C23C4/10 C23C4/12 

FIELD: metallurgy; making erosion-resistant heat-protective coats by plasma spraying.

SUBSTANCE: proposed method may be used in rocketry in manufacture of combustion chambers for liquid propellant engines with cermet erosion-resistant heat-protective coats on base of ZrO₂ NiCr composition. Proposed method includes spraying of nichrome precoat followed by spraying of cermet composition from mechanical powder mixture containing 50-80 wt-% of zirconium dioxide and 50-20 wt-% of nichrome. For spraying cermet composition, use is made of mechanical mixture containing zirconium dioxide and nichrome powders at size of particles of 10-40 mcm and 40-100 mcm, respectively. Powder mixture is delivered under nozzle exit section of plasmatron in way of its motion relative to surface to be coated. Calcium oxide is used as stabilizing additive in zirconium dioxide powder in the amount of 4-6 wt-%.

EFFECT: increase of adhesion strength by 2-3 times; enhanced heat resistance of cermet coats due to phase transition from metal precoat to main coat.

1 dwg, 1 tbl, 1 ex