SINTERED MATERIAL ON BASE OF SILVER-TIN OXIDE FOR ELECTRIC CONTACTS AND METHOD OF ITS MANUFACTURE Russian patent published in 2000 - IPC

FIELD: sintered materials manufactured by powder metallurgy method. SUBSTANCE: sintered material contains, wt.-%: tin oxide, 3.2 to 19.9; indium oxide, 0.05 to 0.4; bismuth oxide, 0.05 to 0.4 and silver, remainder. Method consists in mixing the powders and pressing the powder mixture in cold state at evenly distributed pressure followed by sintering this material at temperatures from 500 to 940 C and stamping wire or profiles. Prior to mixing silver powder with other oxide powders, more than 60 wt.% of tin oxide powder shall have particles more than 1 mkm. Bismuth powder and tin oxide powder are transformed by thermal method into Bi₂Sn₂O₇, that is mixture of powder oxides at more than 60 wt.% of particles having size more than 1 mkm. Then powder mixture is mixed with silver powder and indium oxide powder. EFFECT: limited weldability, limited rise of temperature at changing-over currents between 20 and 100 A; increased service life similar to service life of silver-cadmium oxide. 5 cl, 4 ex