METHOD OF OBTAINING HARD ALLOYS WITH ROUND GRAINS OF TUNGSTEN CARBIDE FOR ROCK CUTTING TOOL Russian patent published in 2019 - IPC B22F3/12 C22C29/08 

FIELD: metallurgy.

SUBSTANCE: invention relates to powder metallurgy, particularly, to coarse-grained solid alloys of WC-Co/Ni/Fe system. It can be used for production of rock-destroying hard-alloy tool. Coarse-grained narrow-grain WC powders with grain size of 5–20 mcm are mixed without grinding with powders of cobalt or iron or nickel in amount of 5.91–9.85 % and functional additive W in amount of 0.5–2 % until homogeneous state. Produced mixture is granulated, molded in molds at pressure of 100–150 MPa and subjected to vacuum-compression sintering at temperatures of 1380–1430 °C, holding at maximum compression vacuum sintering temperature makes 50–70 minutes. Stage of vacuum sintering has duration of 15–25 minutes, stage of sintering under pressure of inert gas in furnace chamber 45–50 atm. has duration of 35–45 minutes. Solid alloy with tungsten carbide grain size Dcp of 4–10 mcm is obtained, wherein 95 % of grains have average diameter of 0.5Dcp–1.75Dcp.

EFFECT: higher bending strength, fracture strength and hardness of coarse solid alloys WC-Co/Ni/Fe.

1 cl, 3 dwg, 6 tbl, 3 ex