High strength, high density isotropic graphite articles - obtd. by vacuuming graphite preform, pressure impregnating with a carbonaceous fluid, carbonising and graphitising

摘要

Homogeneous, isotropic graphite article is made by impregnating a pre-formed isotropic graphite substrate of density 1.6-1.95 g/cc, having an isotropic ratio of =1.05, >=15% total porosity of which at least 50% is interconnected and open to the surface, ave. pore dia. of =5 mu and narrow pore size distribution. A vacuum is drawn on the substrate after which it contacted with phenolic or furfural resin or a pitch and then carbonised, baked and graphitised under conditions correlated to increase density without modifying the grahite matric structure. Prod. has high strength and density without degradation of other props. such as isotropic ratio. Prod. has a compressive strength of at least 20000 psi,flexural strength of >=8000 pi and density of >=2g/cc.