The use of polymeric milling media in the reduction of contamination during mechanical attrition

Aluminum samples were milled in a high-energy ball mill at times ranging from 10 to 500 min in stainless vial/media and nylon vial/media. The crystallite size of aluminum milled in the stainless steel setup reached a plateau at 25 nm around 100 min, whereas the crystallite size of aluminum milled in the nylon setup reached the same plateau at 500 min. Contamination studies were conducted using x-ray fluorescence, hydrogen–carbon–nitrogen analysis, and thermogravimetric analysis. Although organic contamination due to the nylon milling media was high at 12 wt% when milled for 500 min, it is shown that the contaminant could be easily removed by thermal treatment.