Characteristics of U3Si and U3Si2 powders prepared by centrifugal atomization

Abstract

The characteristics: that is, morphology, size distribution, alloy phase and microstructure of U3Si and U3Si2 powders, solidified rapidly by a centrifugal atomization, were investigated. The atomized powders consist of spherical particles with a relatively narrow size distribution independent of the alloy composition. The particle size distribution can be controlled by adjusting the atomization parameters such as feeding rates of the melt and revolution speeds of the disk. The major phases of atomized U3Si and U3Si2 powders are alpha-U and U3Si2 and U3Si2; respectively. The atomized U3Si powder has a dendritic structure of very fine and non-faceted U3Si2 precipitates with less fibric and eutectic U3Si2 structure. The microstructure of U3Si2 powder shows a cellular structure with fine U3Si2 grains and finely dispersed silicon-rich precipitates. The time for complete peritectoid reaction of the atomized U3Si particles and the resulting grain size are greatly reduced, due to the refinement of primary U3Si2 precipitates.