Milling dynamics: Part. II. dynamics of a SPEX mill and a one-dimensional mill

The dynamics of mechanical milling can be described in either local or global terms. Local descriptions consider aspects of powder deformation, fracture, and welding that transpire when powder is entrapped between grinding media during a typical media collision. Global descriptions consider heterogeneous aspects of milling in specific grinding devices; for example, the distribution of impact energies and powder segregation within a mill. In part I of this series, we described facets of attritor global dynamics. In this article, we do the same for a SPEX* mill and for a hypothetical one-dimensional vibratory mill. In a following companion article, we compare the dynamics of an attritor with a SPEX mill and, by extension, other kinds of mills. Specific attention is paid to the relative efficiencies of these devices and the characteristics of powder processed in them. *SPEX is a trademark of SPEX Industries, Edison, NJ