Breakage Mechanism of Mg During Ball Milling with NaCl, KCl and Urea for Nanopowder Production

摘要

In this research, ball milling of magnesium fillings with NaCl, KCl and urea was investigated as a simple way to produce Mg nanoparticles. Effects of feed geometry and milling time on crush mechanism and product size were determined. Optical, scanning and transmission electron microscopes were used to study the morphology of the products. Spherical charge particles were milled under argon atmosphere with 10 wt% cuboidal NaCl at 250 rpm for 50 h. With ball to powder ratio of 10: 1, the average diameter of the product was 17 nm. Addition of NaCl changed the breakage mechanism from ductile-ductile to ductile-brittle, reduced particle size, stopped agglomeration and prevented the undesirable adhesion of particles to walls and balls of the milling machine. Using more than 70 wt% NaCl resulted in conversion of the mechanism from ductile- brittle to brittle-brittle. This resulted in fracture of the particles, but reduced the yield of the system.