METHOD FOR OBTAINING DIAMOND FILM ON HARD-ALLOY ITEMS MADE OF CARBIDE TUNGSTEN Russian patent published in 2017 - IPC C23C16/27 C23C16/44 B82Y30/00 

FIELD: metallurgy.

SUBSTANCE: surface preparation of said hard alloy and gas-phase chemical deposition of carbon are carried out. The preparation of the surface of said hard alloy is carried out by grinding with a diamond paste followed by washing in acetone using ultrasound and removing the cobalt binder in the surface layer of said hard alloy by sequential treatment in concentrated H₂SO₄, Mixtures of H₂O₂:H₂SO₄ in the ratio 1:3 and H₂O₂ for 10, 40, 20 minutes, respectively. Then, an ultrasonic treatment is carried out in a nanodiamond suspension consisting of a oxide ceramic nanopowder ZrO₂-Y₂O₃-CeO₂ and nanodiamond powder and isopropyl alcohol. Then, gas-phase chemical precipitation of carbon is carried out at a microwave power of 700 W, a pressure in the chamber of 25 Torr, a composition of a gas mixture of 99:1 (H₂:CH₄), gas consumption 150 cm³/Min and sample temperature 720°C to obtain a continuous diamond film on said carbide hard-alloy items. In particular embodiments of the invention, the ultrasonic treatment is carried out in a nanodiamond suspension containing a nanopowder of an oxide ceramic ZrO₂-Y₂O₃-CeO₂ with a particle size of 18-21 nm and a nanodiamond powder synthesized by the CVD method, with a size of 90-120 nm.

EFFECT: increasing the nucleation of the diamond phase and obtaining a film on a solid alloy of tungsten carbide that does not contain additional impurities.

2 cl, 4 dwg, 1 ex