New pulverization parameter derived from indentation and dynamic compression of brittle microspheres

• A new attrition model for brittle microspheres was proposed.
• The new model relates material properties to their fracture behavior.
• Failure mechanism was observed in high speed X-ray imaging for dynamic compression.
• Three different failure mechanisms were identified.

Particulates may experience dynamic compression loading during materials handling and processing, which in turn can lead to fracture of the particles. In this study, the dynamic fracture behavior of microspherical particles of soda lime glass (SLG), polycrystalline silica, polycrystalline silicon, barium titanate glass (BTG) and yttrium-stabilized zirconia (YSZ) was characterized with high speed, in situ X-ray phase-contrast imaging to examine the failure mechanisms in situ for spheroidal particles with diameters (d) from 600 to 2000 μm under dynamic compression. Nanoindentation was used to measure the hardness (H) and elastic modulus (E), and microindentation was used to measure the fracture toughness (T  ) of the materials. Based on the experimental results, a new pulverization parameter was proposed to predict the failure mechanism of the materials given by: PP = Hd / TE5/3  . The results showed that high PP values are associated with comminution failure, low PP values are associated with single cracking failure, and intermediate PP values reflect failure modes in between these two extremes.

Figure optionsDownload as PowerPoint slide