| abstract |
Composite members comprising a substrate of fine grained istropic graphite having a density of at least about 1.75 gr/cc, a coefficient of thermal expansion of from about 7.5 to 8.3 inch per inch per DEG Cx10<->6, in which the grains are of a maximum particle size of less than 0.001 inch, and characterized by a relatively uniform distribution of many interconnected fine pores of an average diameter of about 5 microns and less, the pores extending to the surface of the member, and a selected refractory meatal carbide coating firmly bonded to and conforming to the surface of the isotropic graphite member, the refractory metal carbide coating and the isotropic graphite having closely matching coefficients of thermal expansion. Such coated members are particularly well suited for use as anodes and other electrical members, particularly for use at elevated temperatures. Rotating anodes for X-ray tubes comprising such members are an application. Processes for manufacture of such metal carbide coated isotropic graphite members are also disclosed. |