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

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 0.70 Mpa 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 3 mu m FSSS, a higher packing density with 5.54 g/cm(3) was obtained, compared with the 3.71 g/cm(3) of the original powder. For tungsten powder with particle size of 1 mu m FSSS, the big agglomerates disappeared and the particle size distribution become narrower, while small aggregates about 2-3 mu m still exist after the jet milling process. For tungsten powder with particle size of 5 mu m and 10 mu m FSSS, 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. (C) 2017 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.