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

Abstract

The dynamics of mechanical milling can be described in either local or global terms. Local descrip-tions 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.