The solidification structure and application of PM powder by centrifugal atomization
Powders of silver, palladium alloys and gold alloys are produced by the rapidly solidified centrifugal atomization, have been examined in terms of size and shape characteristics by laser scattering technique, scanning electron microscopy and in terms of solidification microstructure by scanning electron microscopy. The powders consist of relatively fine, spherical particles, with many satellite configuration, these observations have been correlated with feature of the processing conditions. It is noted that a number of small particles, with sectional diameters ranging up to about 1 - 100 μm, exhibited equiaxed grain structure, and thus solidification come up to high cooling rate and low oxygen content (<0.05 wt.%). Powders of silver are applied to make electrical contact materials, gold and palladium alloys powders are produced for use in industrial brazing pastes.