THE STRUCTURE OF GRAPHITIC MATERIALS.

During the reporting period arrangements have been made to obtain a supply of a synthetic graphite material manufactured from petroleum coke and a small proportion of natural graphite with a pitch binder. This is supplied by the manufacturers in 2 conditions designated C.Y.9. and E.Y.9., the latter being in the graphitised form heated at 2,500 C. The two types of material are being examined following various heat treatments and creep tests using transmission electron microscopy. Transmission specimens have been prepared by a replication of fracture surfaces and b erosion of 3mm discs cut from 0.5mm thick sheet by a miniature sand blasting unit. Author