SEDL / STP / STP306-EB / STP44390S

Some Comments Regarding Sintering Characteristics in a Radiation Environment

Aitken, EA
General Electric Co., Aircraft Nuclear Propulsion Division, Cincinnati, Ohio

Pages: 8    Published: Jan 1962

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Abstract

Various sintering models are reviewed and their shrinkage characteristics in the initial stages are described. For most crystalline ceramics, diffusion in the bulk is considered the controlling mechanism. Beryllium oxide, however, is an exception when the sintering atmosphere contains appreciable amounts of water vapor. The effects of radiation on the sintering mechanisms are examined and a comparison is made with the few direct observations reported in the literature. The shrinkage rates of Al²O³ compacts determined by Coble are compared with those calculated from radiation-enhanced diffusion. The influence of radiation on shrinkage appears to be significant at low temperatures. If the particle size is less than 0.1 μ, enhanced diffusion from fast neutron collisions should enable measurable shrinkage to occur in a reasonable time for fluxes of 10¹² nv.