HARD ALLOY BODY Russian patent published in 2014 - IPC C22C1/05 B22F3/16 C22C29/08 B23P15/28 

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy, particularly, to production of hard alloy body from hard alloy containing tungsten carbide grains and metallic binder comprising cobalt with definite concentration of tungsten dissolved therein. Hard alloy body has bordering surface area and inner area. Note here that mean fraction of binder in inner area is larger than that in surface area. Note here that carbon concentration in the binder is larger in surface area than that in inner area. Note that hard alloy body does not contain eta-phase and free carbon. Concentration of tungsten dissolved in binder in surface area is smaller than that in inner area and defined as (16.1-σ_t)/0.275, where σ_t is quotient of had alloy body magnetic moment division by mass fraction of binder in this area. Hard alloy body is produced by forming of unsintered blank containing the tungsten carbide grains distributed in cobalt-containing binder, preliminary sintering at 1000-1280°C for 1-3 hours, thermal treatment in carburising medium and liquid-phase sintering at 1320-1400°C.

EFFECT: higher wear resistance and resilience in surface area.

11 cl, 4 dwg, 1 tbl, 1 ex