On the preparation of graphite matrix fuels containing thorium carbide

With the aim of finding the most desirable set of conditions for powder metallurgical preparation of graphite matrix fuels containing thorium carbide, the properties and structure of fuel samples prepared by compacting various mixtures of powdered material followed by heating were investigated. It was found that of the resulting compacts those consisting of (1) purified and milled natural graphite powder, (2) metallic thorium powder and (3) furfuryl alcohol as binder showed the best properties after heating to 600℃. These compacts possessed 1.90∼2.40 g/cc density, 3.5∼10.0 kg/mm² Vickers hardness, a thermal expansion coefficient at 900℃ of about 14 x 10^-6/℃ in the direction parallel to, and 2.5 x 10^-6/℃ normal to pressing direction, and a thermal conductivity, in the same temperature range, of 0.02 (parallel) and 0.07 cal/cm · sec℃ (normal). Since these favorable properties and structural features are not impaired by heating to about 2,000℃ subsequent to treatment at 600℃, it can be said that a new, simple and effective set of conditions for fuel preparation has been found. (author)