Method of increasing the strength of carbon and graphite members

Claim 1

Method of increasing the strength of a porous carbon or graphite body formed from a mixture of granular carbon-containing substances with a carbonizable binder and heating in the absence of air to carbonize the binder which comprises subjecting said body to a single resin impregnation and carbonization by (a) immersing the porous body in a mixture in which 35 to 70% by weight of a hardenable resin containing an aldehyde, selected from the group consisting of phenol-formaldehyde resins, furan resins and melamine resins is admixed with 30 to 65% by weight of a volatile liquid, organic solvent and in the absence of colloidal graphite, to impregnate the pores of the porous body with said mixture; (b) Heating the impregnated porous body to a temperature of 120° to 180° C. to effect hardening the resin in said pores; and (c) carbonizing the impregnating medium by heating in an inert or reducing atmosphere at a rate of at least 3 K/hr to a temperature of 800° to 1300° C.