METHOD OF APPLYING THERMAL-PROTECTIVE COMPOSITE COATING CONTAINING ZIRCONIUM OXIDE, ON METAL SURFACE OF ARTICLE Russian patent published in 2017 - IPC C23C4/10 C23C4/12 

FIELD: engines and pumps, heat exchange.

SUBSTANCE: method of applying thermal-protective composite coating containing zirconium oxide on metal surface of an article involves formation on metal surface of a composite metal-oxide structure by combined sputtering of metals, wherein obtained coating of zirconium oxide is stabilised by yttrium and a gradient transition layer is formed, containing two phases in form of metal phase with composition corresponding to composition of protected surface, and dielectric phase containing zirconium oxide stabilised with yttrium, deposited on said metal phase. Phase ratio in transition layer varies with increase in proportion of oxide phase with increasing film thickness. Gradient transition layer is formed using a magnetron system with two magnetrons, first magnetron is used to sputter a target made of nickel alloy, which corresponds to composition of metal article, and second magnetron is used to sputter a target made of zirconium with additives of stabilising yttrium element. Initial sputtering of targets is carried out in an argon atmosphere, wherein intensity of atomic flux formed from said first target is greater than intensity of atomic flux from said second target. After formation of primary solid layer of nickel alloy, oxygen is fed into working chamber to ensure jet spraying to form sprayed zirconium oxide film at non-oxidised nickel. In process of sputtering oxygen partial pressure is gradually increased to 1.5⋅10^-3 Pa, and power of first magnetron, sputtering first target from nickel alloy, is reduced up to its complete disconnection, then sputtering of zirconium oxide continues until film of required thickness is achieved. When performing said operations, a smooth transition is formed from said layer of nickel alloy to a film of zirconium oxide with mechanical properties, smoothly varying thickness of obtained layer with isotropic distribution of internal stresses at cyclic thermal loads.

EFFECT: higher mechanical strength of coating, high heat resistance, as well as high adhesion and cohesion.

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