Crystal growth kinetics of nanocrystalline aluminum prepared by mechanical attrition in nylon media

Grain growth in nanocrystalline (nc) aluminum with an initial grain sizes of 22 and 40 nm produced by mechanical attrition using stainless steel and nylon media, respectively, was studied through X-ray diffraction, differential scanning calorimetry, and electron microscopy. Two-grain growth regimes are observed for aluminum milled in both nylon and stainless steel media. Grain growth occurred above T/TM of 0.72 and 0.83 for samples milled in stainless steel and nylon, respectively. The enhanced stability of Al grain size milled in nylon is attributed to the nylon impurity (phase).