METHOD FOR PRODUCING COMPOSITION MATERIAL FOR ELECTRICAL- ENGINEERING DESIGNATION Russian patent published in 2007 - IPC B22F3/12 C22C29/08 

FIELD: powder metallurgy, namely production of composition materials on base of tungsten carbide for making electric contacts.

SUBSTANCE: method for producing composition material comprises steps of mixing powders by two stages: at first mixing powders of tungsten-cobalt hard alloy and copper, then mixing prepared mixture with graphite. Alcoholic solution of orthophosphoric acid is added to prepared mixture in quantity providing next relation of components of sintered material, mass %: copper, 30 - 50; nickel, 5.0 - 15.0; graphite, 1.0 - 3.0; phosphorus, 0.8 - 1.5; hard alloy, the balance. Then stages of plasticizing, pressing and liquid-phase sintering in vacuum are realized. At heating process during sintering stage three isothermal soaking stages are performed. At first soaking is performed at temperature of creating easy-to-melt eutectics Cu-P; then sintering is performed at temperature of creating easy-to-melt eutectics Ni - P and third sintering stage is performed at temperature of creating easy-to-melt eutectics Co - P.

EFFECT: enhanced rigidity and wear resistance of material.

2 cl, 2 dwg