SINTERED HARD METAL PART AND METHOD TO THIS END Russian patent published in 2014 - IPC C22C1/05 C22C29/08 B22F3/12 

FIELD: process engineering.

SUBSTANCE: invention relates to powder metallurgy, particularly, to production of cutting tools from hard alloys. It can be used for production of inserts for metal forming, mining and cold forming. Grain grinding additive including grain grinding agent and carbon and/or nitrogen as well as grain growth activator are placed at, at least, a part of the surface of WC-based initial material blank including one or more solid phase components and binder to sinter the blank. Said additive represents carbide, mixed carbide, carbonitride or nitride. Hard alloy part includes WC-based solid phase and binding phase. Note here that one part on the zone intermediate part has lower mean content of binder that that located deeper in the part and at least one part of the zone top surface zone has, on the average, greater mean WC grain size compared with mid surface zone. Hard alloy part features at least one hardness peak located under the surface.

EFFECT: higher breaking resistance.

19 cl, 11 dwg, 6 tbl, 5 ex