METHOD OF FABRICATING PROTECTIVE COATING ITEM FROM BERYLLIUM AND ITS ALLOYS Russian patent published in 2009 - IPC C03C8/10 C23C22/37 

FIELD: metallurgy.

SUBSTANCE: invention refers to machine building and to process of fabricating items out of non-ferrous alloys, particularly to protective coatings against gas corrosion during continuous operation and at process heating during production of items and semi-products of high quality out of beryllium and its alloys at thermal and thermal-mechanical forming operations. The method includes preparing surface of the item and its successive immunisation by means of applying water solution on the surface of the item; this water solution contains potassium bichromate 170-250 g/l, hydrofluoric acid 7.5-11.5 g/l, sodium fluoride 3-12 g/l, beryllium 0.1-0.5 g/l, and chromium oxide 0.1-0.5 g/l with following thermal treatment of this surface and with applying on it a non-organic enamel coat of the system B₂O₃-PbO-CaO-MgO-Al₂O₃-Cr₂O₃-CoO-SiO₂. Immunisation is carried out during 30-80 minutes at the temperature of 45-70°C, while thermal treatment of the immunised surface is performed at the temperature of 550-650°C during 0.5-1.5 h. Forming non-organic enamel coating of system B₂O₃-PbO-CaO-MgO-Al₂O₃-Cr₂O₃-CoO-SiO₂ is executed at the temperature of 520-600°C during 0.1-0.5 h.

EFFECT: producing protective coating possessing upgraded temperature resistance up to 1200°C and high heat resistance on items from beryllium and its alloy.

4 cl, 3 tbl