Physicochemical properties of ball milled boron particles: Dry vs. wet ball milling process

Physicochemical properties of both dry and wet milled boron particles with sub-micron sizes were investigated. Milling process was performed in N-2 atmosphere and the mass ratio of tungsten carbide ball and boron was fixed at 20:1. It was found that the size distribution of boron particles grinded under dry milling condition was much broader than that under wet milling condition, and the size reduction rate in the dry process was faster than that in the wet process. Dry milled boron particles showed rougher surface morphology and more agglomerated particles, compared to wet milled boron particles. On the basis of X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and FT-IR results, it was confirmed that the initial oxide layer on the surface of boron particles was removed in the wet milling process, and B-O-C bond was newly formed on the surface of boron. On the other hand, XRD results showed that crystalline boron oxide layer was formed on the surface of dry milled boron particles. In addition, appropriate cleaning cycles and drying time for wet milled boron particles were suggested on the basis of FT-IR data. (C) 2014 Elsevier B.V. All rights reserved.