METHOD OF PLASMA CHEMICAL DEPOSITION FROM GASEOUS PHASE ON INNER SURFACE OF HOLLOW ITEM Russian patent published in 2012 - IPC C23C16/22 C23C14/24 H01J19/57 B01J19/12 

FIELD: metallurgy.

SUBSTANCE: method of plasma chemical treatment from gaseous phase for application of coating to or removal of material from inner surface of hollow item (42), namely from non-metallic material extended throughout the length and one hole (43) involves the following stages. Hollow item is installed in the middle of vacuum chamber (40) with earthed inner side so that minimum distance between external wall of hollow item and internal wall of vacuum chamber is 15 cm. High-frequency electrode (41) is located inside vacuum chamber. Gas tube (44) consisting of a tube with inner diameter of 0.001-10 mm, maximum outer diameter of 12 mm and end nozzle with hole diameter on the end of 0.002-6 mm is introduced through the hole made in hollow item. Gas tube is installed in hollow item so that gas tube is located in the middle relative to cross section of hollow item, and nozzle of gas tube is located at the distance comprising two thirds of the hollow item length of hollow item hole. Sealing of vacuum chamber and pumping of air from it is performed till residual pressure is 0.001-20 Pa. Introduction of inert working gas, as well as one or several reaction gases through gas supply device and gas tube to hollow item and ignition of plasma of hollow space (45) of the item at formation of plasma on gas tube tip is performed by creation of high-frequency electric field on HF electrode.

EFFECT: improved cleaning of hollow items; improved corrosion protection of surfaces with applied coating; reducing the friction coefficient of inner surface and improving heat release.

16 cl, 10 dwg