Ball-milled powders, morphology

Two important morphological parameters characterizing ball-milled powders are the particle and grain size of constituent phases within the powders. In our laboratory, the size measurement of the powder particles is carried out by attaching loose powder to sticky carbon tape and taking pictures under secondary electron (SE) mode in the SEM. The images are then analyzed by an image analysis software. The size of the powders is calculated as the particle equivalent circle diameter, ECD = AA/nf, where A represents the projected particle area. Usually from -300 to 700 particles are analyzed for each batch. 

FIGURE 6.3 (a) Morphology of ball-milled NiO and SDC powders produced separately and (b) NiO-SDC composite powders coproduced by spray pyrolysis, showing a possible mechanism by which the composite powders retain a higher surface area resulting in a higher performance [19]. Reprinted from [19] with permission from Elsevier. 

Fig. 3.6 Secondary electron micrographs showing morphology of (a) as-received NaAlH and (b) after milling for 5 h in the magneto mill Uni-BaU-MiU 5 under HES57 mode in argon (two magnets at 5 and 7 o clock positions ball to powder weight ratio 50 1)...

Fig. 3.41 Scanning electron micrographs showing morphology of powder particles after ball milling for 20 h for (a) (NaBH + 70 wt%MgH2), (b) (NaBH + 80 wt%MgH2) and (c) (NaBH + 90 wt%MgH2) composites. Particle size ECD shown...

Fig. 3.47 Scanning electron micrographs of the morphology of powder particles after ball milling for (a) NaBH + 12 wt%Mg, (b) NaBH + 55 wt%Mg, (c) NaBH + 73 wt%Mg, (d) NaBH + 92 wt%Mg composites...

Lee, G.G., Hashimoto, H. and Watanabe, R. (1995) Development of particle morphology during dry ball milling of Cu powder. Material Transactions of The Japan Institute of Metals (JIM), 36, 548-54. 

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