Particle size distribution control and related properties improvements of tungsten powders by fluidized bed jet milling

Abstract

Fine grinding process of different particle size tungsten powders was carried out by fluidized bed jet milling. The results showed that the jet milling treatment caused deagglomeration of tungsten powders, which led to particles sufficient dispersion and narrow particle size distribution. Grinding gas pressure of 0.70Mpa made the particles achieve high speed which promoted the particles collision contributing to particle dispersion and shape modification. For tungsten powder with particle size of 3μmFSSS, a higher packing density with 5.54g/cm3 was obtained, compared with the 3.71g/cm3 of the original powder. For tungsten powder with particle size of 1μmFSSS, the big agglomerates disappeared and the particle size distribution become narrower, while small aggregates about 2–3μm still exist after the jet milling process. For tungsten powder with particle size of 5μm and 10μmFSSS, different medium diameter particle size and narrow particle size distribution of monodisperse tungsten powders can be produced by the optimized jet milling parameters. More important, the effective dispersion, favorable shape modification and precise classification have been achieved in the simple process.