Observations on the radial and axial shrinkage behaviour of CaF 2 and UO 2 Powder compacts

Abstract

The effect of compacting pressure, shape and size of powder particles, and sintering temperature on the radial, axial, and radial-to-axial shrinkage ratio for CaF 2 and UO 2 were studied. For CaF 2 the radial-to-axial shrinkage ratio was close to unity regardless of particle size, compacting pressure and sintering temperature. The same effect was observed in UO 2 powder compacts. The radial and axial density distributions in CaF 2 compacts were determined. Unlike in soft metals, it was found that both distributions were almost identical and they also behaved the same with increasing compacting pressure. The radial-to-axial shrinkage ratio of a slip-cast CaF 2 specimen was also found to be close to unity. The value of the radial-to-axial shrinkage ratio in CaF 2 and UO 2, which approached unity in both cases, was attributed to the similarity in radial and axial density distributions.