METHOD OF PRODUCING THICK-LAYER HEAT-SHIELDING COATINGS BY MICROARC OXIDATION ON HIGH-SILICON ALUMINUM ALLOY Russian patent published in 2019 - IPC C25D11/06 

FIELD: technological processes.

SUBSTANCE: invention relates to electroplating and can be used for thermal protection of parts of machine building, for example, pistons and heads of cylinder blocks of internal combustion engines. Method includes installation of part in electrolyte on current-conducting holder, covered with insulating material, creation of working voltage between part and electrolyte, which is an aqueous solution of caustic potassium and liquid glass at concentration of each substance 4 g/l, high voltage before occurrence of micro-arc discharge on surface of part, wherein micro-arc oxidation is carried out for 1.5–2.0 hours at current strength I=10–17 A, ratio of anode and cathode current 1:1 and voltage at anode Ua=250–350 V.

EFFECT: increasing thickness of oxide ceramic coating and, accordingly, its heat-protective properties, on high-silicon hypereutectic aluminum alloys with silicon content higher than 12 %.

1 cl, 1 ex