METHOD TO PRODUCE SINTERED SOLID ALLOYS BASED ON TUNGSTEN CARBIDE Russian patent published in 1997 - IPC

FIELD: solid alloys processes using operations mode variations and selection of carbidization medium composition. SUBSTANCE: aim is to increase plastic properties, strength, to improve quality of produced powder due to decrease of free carbon concentration in tungsten carbide, to simplify whole process and make it cheaper. Method provides for tungsten trioxide reduction, carbidization in methane-hydrogen medium, mixing of tungsten carbide with metallic binder, pressing and calcining. Carbidization is carried out under temperature of 1800 - 2500 C and with gas mixture usage of 1 - 4 cu-m/h. Medium, that has 0,2 - 4.5 vol % of methane, is used as methane-hydrogen medium. In the case under temperature of 1800 C carbidization is carried out in methane-hydrogen medium with methane concentration of 0.2 - 1.2 vol % and mixture usage of 3,0 - 4.0 cu-m/h; under temperature of 2000 C - 0.5 - 1.8 vol % and mixture usage of 2.0 - 3.0 cu-m/h; under temperature of 2200 C - 0.7 - 0.25 vol % and mixture usage of 1.5 - 2.5 cu-m/h; under temperature of 2500 C - 2.0 - 4.5 vol % and mixture usage of 1.0 - 1.5 cu-m/h. EFFECT: increased plastic properties, strength, improved quality of produced powder. 5 cl, 1 dwg , 1 tbl