METHOD OF PRODUCING GRAPHITE-BASED MATERIAL FOR SLIDING ELECTRIC CONTACTS AND MATERIAL Russian patent published in 2019 - IPC C04B35/532 C04B35/84 H01R39/26 

FIELD: electrical engineering.

SUBSTANCE: invention relates to electrical engineering, in particular to materials for sliding electric contacts used on electric transport. Method of making material for sliding electric contacts involves the following stages: (A) producing a mixture based on graphite, coke and a coke-forming binder, where the content of graphite is not less than 15 % of the weight of the mixture; (B) forming, from a mixture, a workpiece; (C) annealing the workpiece, which provides formation of residual coke from the binder, to produce a porous workpiece with open porosity; (D) gas-phase thermogradient saturation of workpiece from stage (C) with pyrolytic carbon in reaction chamber by means of pulsed supply of hydrocarbon gas and its decomposition with formation of pyrolytic carbon on surface of open pores in moving zone of pyrolysis and its further pumping. Moving pyrolysis zone is created by maintaining the temperature of one of the walls of said billet in the range of decomposition temperatures of said hydrocarbon gas and increasing the temperature of the opposite wall of the workpiece from the ambient temperature at the beginning of the gas-phase thermogradient saturation process to the decomposition temperatures of said hydrocarbon gas at the end of the gas-phase thermogradient saturation process at rate of 1.0–10.0 °C/hour. Invention makes it possible to produce material for sliding electric contacts with improved operational characteristics: hardness on outer surface of not less than 36 HS, hardness at depth equal to half of thickness of material, measured by layer-by-layer method, at least 30 HS, specific electric resistance, 4–17 mcOhm⋅m, volume loss in electric arc, (2.3 kA, 0.5 s) 3–49 mm³ and density of 1.33–1.8 g/cm³.

EFFECT: disclosed is a method of making graphite-based material for sliding electrical contacts and material.

11 cl, 1 ex, 1 tbl